Re-work ad-hoc command (XEP-0050) implementation

Fixes SMACK-933.

smack-experimental/src/main/java/org/jivesoftware/smackx/mam/MamManager.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright © 2017-2020 Florian Schmaus, 2016-2017 Fernando Ramirez
+ * Copyright © 2017-2023 Florian Schmaus, 2016-2017 Fernando Ramirez
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -44,8 +44,8 @@ import org.jivesoftware.smack.packet.Stanza;
 import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smack.util.StringUtils;
 
+import org.jivesoftware.smackx.commands.AdHocCommand;
 import org.jivesoftware.smackx.commands.AdHocCommandManager;
-import org.jivesoftware.smackx.commands.RemoteCommand;
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 import org.jivesoftware.smackx.disco.packet.DiscoverItems;
@@ -233,7 +233,7 @@ public final class MamManager extends Manager {
         super(connection);
         this.archiveAddress = archiveAddress;
         serviceDiscoveryManager = ServiceDiscoveryManager.getInstanceFor(connection);
-        adHocCommandManager = AdHocCommandManager.getAddHocCommandsManager(connection);
+        adHocCommandManager = AdHocCommandManager.getInstance(connection);
     }
 
     /**
@@ -759,7 +759,7 @@ public final class MamManager extends Manager {
         return false;
     }
 
-    public RemoteCommand getAdvancedConfigurationCommand() throws InterruptedException, XMPPException, SmackException {
+    public AdHocCommand getAdvancedConfigurationCommand() throws InterruptedException, XMPPException, SmackException {
         DiscoverItems discoverItems = adHocCommandManager.discoverCommands(archiveAddress);
         for (DiscoverItems.Item item : discoverItems.getItems()) {
             if (item.getNode().equals(ADVANCED_CONFIG_NODE))

smack-extensions/src/main/java/org/jivesoftware/smackx/admin/ServiceAdministrationManager.java

@@ -1,6 +1,6 @@
 /**
  *
- * Copyright 2016-2020 Florian Schmaus
+ * Copyright 2016-2023 Florian Schmaus
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -27,8 +27,9 @@ import org.jivesoftware.smack.SmackException.NotConnectedException;
 import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
 
+import org.jivesoftware.smackx.commands.AdHocCommand;
 import org.jivesoftware.smackx.commands.AdHocCommandManager;
-import org.jivesoftware.smackx.commands.RemoteCommand;
+import org.jivesoftware.smackx.commands.AdHocCommandResult;
 import org.jivesoftware.smackx.xdata.form.FillableForm;
 
 import org.jxmpp.jid.EntityBareJid;
@@ -56,37 +57,38 @@ public class ServiceAdministrationManager extends Manager {
     public ServiceAdministrationManager(XMPPConnection connection) {
         super(connection);
 
-        adHocCommandManager = AdHocCommandManager.getAddHocCommandsManager(connection);
+        adHocCommandManager = AdHocCommandManager.getInstance(connection);
     }
 
-    public RemoteCommand addUser() {
+    public AdHocCommand addUser() {
         return addUser(connection().getXMPPServiceDomain());
     }
 
-    public RemoteCommand addUser(Jid service) {
+    public AdHocCommand addUser(Jid service) {
         return adHocCommandManager.getRemoteCommand(service, COMMAND_NODE_HASHSIGN + "add-user");
     }
 
     public void addUser(final EntityBareJid userJid, final String password)
                     throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        RemoteCommand command = addUser();
+        AdHocCommand command = addUser();
-        command.execute();
 
-        FillableForm answerForm = new FillableForm(command.getForm());
+        AdHocCommandResult.StatusExecuting commandExecutingResult = command.execute().asExecutingOrThrow();
+
+        FillableForm answerForm = commandExecutingResult.getFillableForm();
 
         answerForm.setAnswer("accountjid", userJid);
         answerForm.setAnswer("password", password);
         answerForm.setAnswer("password-verify", password);
 
-        command.execute(answerForm);
+        AdHocCommandResult result = command.execute(answerForm);
-        assert command.isCompleted();
+        assert result.isCompleted();
     }
 
-    public RemoteCommand deleteUser() {
+    public AdHocCommand deleteUser() {
         return deleteUser(connection().getXMPPServiceDomain());
     }
 
-    public RemoteCommand deleteUser(Jid service) {
+    public AdHocCommand deleteUser(Jid service) {
         return adHocCommandManager.getRemoteCommand(service, COMMAND_NODE_HASHSIGN + "delete-user");
     }
 
@@ -98,14 +100,14 @@ public class ServiceAdministrationManager extends Manager {
 
     public void deleteUser(Set<EntityBareJid> jidsToDelete)
                     throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        RemoteCommand command = deleteUser();
+        AdHocCommand command = deleteUser();
-        command.execute();
+        AdHocCommandResult.StatusExecuting commandExecutingResult = command.execute().asExecutingOrThrow();
 
-        FillableForm answerForm = new FillableForm(command.getForm());
+        FillableForm answerForm = commandExecutingResult.getFillableForm();
 
         answerForm.setAnswer("accountjids", jidsToDelete);
 
-        command.execute(answerForm);
+        AdHocCommandResult result = command.execute(answerForm);
-        assert command.isCompleted();
+        assert result.isCompleted();
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AbstractAdHocCommand.java

@@ -0,0 +1,277 @@
+/**
+ *
+ * Copyright 2005-2007 Jive Software.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+import org.jivesoftware.smack.SmackException.NoResponseException;
+import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.XMPPException.XMPPErrorException;
+import org.jivesoftware.smack.packet.StanzaError;
+import org.jivesoftware.smack.util.StringUtils;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Action;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Status;
+
+/**
+ * An ad-hoc command is responsible for executing the provided service and
+ * storing the result of the execution. Each new request will create a new
+ * instance of the command, allowing information related to executions to be
+ * stored in it. For example suppose that a command that retrieves the list of
+ * users on a server is implemented. When the command is executed it gets that
+ * list and the result is stored as a form in the command instance, i.e. the
+ * <code>getForm</code> method retrieves a form with all the users.
+ * <p>
+ * Each command has a <code>node</code> that should be unique within a given JID.
+ * </p>
+ * <p>
+ * Commands may have zero or more stages. Each stage is usually used for
+ * gathering information required for the command execution. Users are able to
+ * move forward or backward across the different stages. Commands may not be
+ * cancelled while they are being executed. However, users may request the
+ * "cancel" action when submitting a stage response indicating that the command
+ * execution should be aborted. Thus, releasing any collected information.
+ * Commands that require user interaction (i.e. have more than one stage) will
+ * have to provide the data forms the user must complete in each stage and the
+ * allowed actions the user might perform during each stage (e.g. go to the
+ * previous stage or go to the next stage).
+ * </p>
+ * All the actions may throw an XMPPException if there is a problem executing
+ * them. The <code>XMPPError</code> of that exception may have some specific
+ * information about the problem. The possible extensions are:
+ * <ul>
+ * <li><i>malformed-action</i>. Extension of a <i>bad-request</i> error.</li>
+ * <li><i>bad-action</i>. Extension of a <i>bad-request</i> error.</li>
+ * <li><i>bad-locale</i>. Extension of a <i>bad-request</i> error.</li>
+ * <li><i>bad-payload</i>. Extension of a <i>bad-request</i> error.</li>
+ * <li><i>bad-sessionid</i>. Extension of a <i>bad-request</i> error.</li>
+ * <li><i>session-expired</i>. Extension of a <i>not-allowed</i> error.</li>
+ * </ul>
+ * <p>
+ * See the <code>SpecificErrorCondition</code> class for detailed description
+ * of each one.
+ * </p>
+ * Use the <code>getSpecificErrorConditionFrom</code> to obtain the specific
+ * information from an <code>XMPPError</code>.
+ *
+ * @author Gabriel Guardincerri
+ * @author Florian Schmaus
+ *
+ */
+public abstract class AbstractAdHocCommand {
+    private final List<AdHocCommandData> requests = new ArrayList<>();
+    private final List<AdHocCommandResult> results = new ArrayList<>();
+
+    private final String node;
+
+    private final String name;
+
+    /**
+     * The session ID of this execution.
+     */
+    private String sessionId;
+
+    protected AbstractAdHocCommand(String node, String name) {
+        this.node = StringUtils.requireNotNullNorEmpty(node, "Ad-Hoc command node must be given");
+        this.name = name;
+    }
+
+    protected AbstractAdHocCommand(String node) {
+        this(node, null);
+    }
+
+    void addRequest(AdHocCommandData request) {
+        requests.add(request);
+    }
+
+    void addResult(AdHocCommandResult result) {
+        results.add(result);
+    }
+
+    /**
+     * Returns the specific condition of the <code>error</code> or <code>null</code> if the
+     * error doesn't have any.
+     *
+     * @param error the error the get the specific condition from.
+     * @return the specific condition of this error, or null if it doesn't have
+     *         any.
+     */
+    public static SpecificErrorCondition getSpecificErrorCondition(StanzaError error) {
+        // This method is implemented to provide an easy way of getting a packet
+        // extension of the XMPPError.
+        for (SpecificErrorCondition condition : SpecificErrorCondition.values()) {
+            if (error.getExtension(condition.toString(),
+                    AdHocCommandData.SpecificError.namespace) != null) {
+                return condition;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Returns the human readable name of the command.
+     *
+     * @return the human readable name of the command
+     */
+    public String getName() {
+        return name;
+    }
+
+    /**
+     * Returns the unique identifier of the command. It is unique for the
+     * <code>OwnerJID</code>.
+     *
+     * @return the unique identifier of the command.
+     */
+    public String getNode() {
+        return node;
+    }
+
+    public String getSessionId() {
+        return sessionId;
+    }
+
+    protected void setSessionId(String sessionId) {
+        assert this.sessionId == null || this.sessionId.equals(sessionId);
+        this.sessionId = StringUtils.requireNotNullNorEmpty(sessionId, "Must provide a session ID");
+    }
+
+    public AdHocCommandData getLastRequest() {
+        if (requests.isEmpty()) return null;
+        return requests.get(requests.size() - 1);
+    }
+
+    public AdHocCommandResult getLastResult() {
+        if (results.isEmpty()) return null;
+        return results.get(results.size() - 1);
+    }
+
+    /**
+     * Returns the notes that the command has at the current stage.
+     *
+     * @return a list of notes.
+     */
+    public List<AdHocCommandNote> getNotes() {
+        AdHocCommandResult result = getLastResult();
+        if (result == null) return null;
+
+        return result.getResponse().getNotes();
+    }
+
+    /**
+     * Cancels the execution of the command. This can be invoked on any stage of
+     * the execution. If there is a problem executing the command it throws an
+     * XMPPException.
+     *
+     * @throws NoResponseException if there was no response from the remote entity.
+     * @throws XMPPErrorException if there is a problem executing the command.
+     * @throws NotConnectedException if the XMPP connection is not connected.
+     * @throws InterruptedException if the calling thread was interrupted.
+     */
+    public abstract void cancel() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+
+    /**
+     * Returns a collection with the allowed actions based on the current stage.
+     * Possible actions are: {@link AllowedAction#prev prev}, {@link AllowedAction#next next} and
+     * {@link AllowedAction#complete complete}. This method will be only invoked for commands that
+     * have one or more stages.
+     *
+     * @return a collection with the allowed actions based on the current stage
+     *      as defined in the SessionData.
+     */
+    public final Set<AllowedAction> getActions() {
+        AdHocCommandResult result = getLastResult();
+        if (result == null) return null;
+
+        return result.getResponse().getActions();
+    }
+
+    /**
+     * Returns the action available for the current stage which is
+     * considered the equivalent to "execute". When the requester sends his
+     * reply, if no action was defined in the command then the action will be
+     * assumed "execute" thus assuming the action returned by this method. This
+     * method will never be invoked for commands that have no stages.
+     *
+     * @return the action available for the current stage which is considered
+     *      the equivalent to "execute".
+     */
+    protected AllowedAction getExecuteAction() {
+        AdHocCommandResult result = getLastResult();
+        if (result == null) return null;
+
+        return result.getResponse().getExecuteAction();
+    }
+
+    /**
+     * Returns the status of the current stage.
+     *
+     * @return the current status.
+     */
+    public Status getStatus() {
+        AdHocCommandResult result = getLastResult();
+        if (result == null) return null;
+
+        return result.getResponse().getStatus();
+    }
+
+    /**
+     * Check if this command has been completed successfully.
+     *
+     * @return <code>true</code> if this command is completed.
+     * @since 4.2
+     */
+    public boolean isCompleted() {
+        return getStatus() == AdHocCommandData.Status.completed;
+    }
+
+    /**
+     * Returns true if the <code>action</code> is available in the current stage.
+     * The {@link Action#cancel cancel} action is always allowed. To define the
+     * available actions use the <code>addActionAvailable</code> method.
+     *
+     * @param action The action to check if it is available.
+     * @return True if the action is available for the current stage.
+     */
+    public final boolean isValidAction(Action action) {
+        if (action == Action.cancel) {
+            return true;
+        }
+
+        final AllowedAction executeAction;
+        if (action == Action.execute) {
+            AdHocCommandResult result = getLastResult();
+            executeAction = result.getResponse().getExecuteAction();
+
+            // This is basically the case that was clarified with
+            // https://github.com/xsf/xeps/commit/fdaee2da8ffd34b5b5151e90ef1df8b396a06531 and
+            // https://github.com/xsf/xeps/pull/591.
+            if (executeAction == null) {
+                return false;
+            }
+        } else {
+            executeAction = action.allowedAction;
+            assert executeAction != null;
+        }
+
+        Set<AllowedAction> actions = getActions();
+        return actions != null && actions.contains(executeAction);
+    }
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommand.java

@@ -16,193 +16,68 @@
  */
 package org.jivesoftware.smackx.commands;
 
-import java.util.List;
-
 import org.jivesoftware.smack.SmackException.NoResponseException;
 import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.XMPPException.XMPPErrorException;
-import org.jivesoftware.smack.packet.StanzaError;
+import org.jivesoftware.smack.packet.IQ;
-
+import org.jivesoftware.smack.util.Objects;
 import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
 import org.jivesoftware.smackx.xdata.form.FillableForm;
+import org.jivesoftware.smackx.xdata.form.SubmitForm;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
 import org.jxmpp.jid.Jid;
 
 /**
- * An ad-hoc command is responsible for executing the provided service and
+ * Represents a ad-hoc command invoked on a remote entity. Invoking one of the
- * storing the result of the execution. Each new request will create a new
+ * {@link #execute()}, {@link #next(SubmitForm)},
- * instance of the command, allowing information related to executions to be
+ * {@link #prev()}, {@link #cancel()} or
- * stored in it. For example suppose that a command that retrieves the list of
+ * {@link #complete(SubmitForm)} actions results in executing that
- * users on a server is implemented. When the command is executed it gets that
+ * action on the remote entity. In response to that action the internal state
- * list and the result is stored as a form in the command instance, i.e. the
+ * of the this command instance will change. For example, if the command is a
- * <code>getForm</code> method retrieves a form with all the users.
+ * single stage command, then invoking the execute action will execute this
- * <p>
+ * action in the remote location. After that the local instance will have a
- * Each command has a <code>node</code> that should be unique within a given JID.
+ * state of "completed" and a form or notes that applies.
- * </p>
- * <p>
- * Commands may have zero or more stages. Each stage is usually used for
- * gathering information required for the command execution. Users are able to
- * move forward or backward across the different stages. Commands may not be
- * cancelled while they are being executed. However, users may request the
- * "cancel" action when submitting a stage response indicating that the command
- * execution should be aborted. Thus, releasing any collected information.
- * Commands that require user interaction (i.e. have more than one stage) will
- * have to provide the data forms the user must complete in each stage and the
- * allowed actions the user might perform during each stage (e.g. go to the
- * previous stage or go to the next stage).
- * </p>
- * All the actions may throw an XMPPException if there is a problem executing
- * them. The <code>XMPPError</code> of that exception may have some specific
- * information about the problem. The possible extensions are:
- * <ul>
- * <li><i>malformed-action</i>. Extension of a <i>bad-request</i> error.</li>
- * <li><i>bad-action</i>. Extension of a <i>bad-request</i> error.</li>
- * <li><i>bad-locale</i>. Extension of a <i>bad-request</i> error.</li>
- * <li><i>bad-payload</i>. Extension of a <i>bad-request</i> error.</li>
- * <li><i>bad-sessionid</i>. Extension of a <i>bad-request</i> error.</li>
- * <li><i>session-expired</i>. Extension of a <i>not-allowed</i> error.</li>
- * </ul>
- * <p>
- * See the <code>SpecificErrorCondition</code> class for detailed description
- * of each one.
- * </p>
- * Use the <code>getSpecificErrorConditionFrom</code> to obtain the specific
- * information from an <code>XMPPError</code>.
  *
  * @author Gabriel Guardincerri
+ * @author Florian Schmaus
  *
  */
-public abstract class AdHocCommand {
+public class AdHocCommand extends AbstractAdHocCommand {
-    // TODO: Analyze the redesign of command by having an ExecutionResponse as a
-    // TODO: result to the execution of every action. That result should have all the
-    // TODO: information related to the execution, e.g. the form to fill. Maybe this
-    // TODO: design is more intuitive and simpler than the current one that has all in
-    // TODO: one class.
-
-    private AdHocCommandData data;
-
-    public AdHocCommand() {
-        super();
-        data = new AdHocCommandData();
-    }
 
     /**
-     * Returns the specific condition of the <code>error</code> or <code>null</code> if the
+     * The connection that is used to execute this command
-     * error doesn't have any.
-     *
-     * @param error the error the get the specific condition from.
-     * @return the specific condition of this error, or null if it doesn't have
-     *         any.
      */
-    public static SpecificErrorCondition getSpecificErrorCondition(StanzaError error) {
+    private final XMPPConnection connection;
-        // This method is implemented to provide an easy way of getting a packet
-        // extension of the XMPPError.
-        for (SpecificErrorCondition condition : SpecificErrorCondition.values()) {
-            if (error.getExtension(condition.toString(),
-                    AdHocCommandData.SpecificError.namespace) != null) {
-                return condition;
-            }
-        }
-        return null;
-    }
 
     /**
-     * Set the human readable name of the command, usually used for
+     * The full JID of the command host
-     * displaying in a UI.
-     *
-     * @param name the name.
      */
-    public void setName(String name) {
+    private final Jid jid;
-        data.setName(name);
-    }
 
     /**
-     * Returns the human readable name of the command.
+     * Creates a new RemoteCommand that uses an specific connection to execute a
+     * command identified by <code>node</code> in the host identified by
+     * <code>jid</code>
      *
-     * @return the human readable name of the command
+     * @param connection the connection to use for the execution.
+     * @param node the identifier of the command.
+     * @param jid the JID of the host.
      */
-    public String getName() {
+    protected AdHocCommand(XMPPConnection connection, String node, Jid jid) {
-        return data.getName();
+        super(node);
+        this.connection = Objects.requireNonNull(connection);
+        this.jid = Objects.requireNonNull(jid);
     }
 
-    /**
+    public Jid getOwnerJID() {
-     * Sets the unique identifier of the command. This value must be unique for
+        return jid;
-     * the <code>OwnerJID</code>.
-     *
-     * @param node the unique identifier of the command.
-     */
-    public void setNode(String node) {
-        data.setNode(node);
     }
 
-    /**
+    @Override
-     * Returns the unique identifier of the command. It is unique for the
+    public final void cancel() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-     * <code>OwnerJID</code>.
+        executeAction(AdHocCommandData.Action.cancel);
-     *
-     * @return the unique identifier of the command.
-     */
-    public String getNode() {
-        return data.getNode();
-    }
-
-    /**
-     * Returns the full JID of the owner of this command. This JID is the "to" of a
-     * execution request.
-     *
-     * @return the owner JID.
-     */
-    public abstract Jid getOwnerJID();
-
-    /**
-     * Returns the notes that the command has at the current stage.
-     *
-     * @return a list of notes.
-     */
-    public List<AdHocCommandNote> getNotes() {
-        return data.getNotes();
-    }
-
-    /**
-     * Adds a note to the current stage. This should be used when setting a
-     * response to the execution of an action. All the notes added here are
-     * returned by the {@link #getNotes} method during the current stage.
-     * Once the stage changes all the notes are discarded.
-     *
-     * @param note the note.
-     */
-    protected void addNote(AdHocCommandNote note) {
-        data.addNote(note);
-    }
-
-    public String getRaw() {
-        return data.getChildElementXML().toString();
-    }
-
-    /**
-     * Returns the form of the current stage. Usually it is the form that must
-     * be answered to execute the next action. If that is the case it should be
-     * used by the requester to fill all the information that the executor needs
-     * to continue to the next stage. It can also be the result of the
-     * execution.
-     *
-     * @return the form of the current stage to fill out or the result of the
-     *         execution.
-     */
-    public DataForm getForm() {
-        return data.getForm();
-    }
-
-    /**
-     * Sets the form of the current stage. This should be used when setting a
-     * response. It could be a form to fill out the information needed to go to
-     * the next stage or the result of an execution.
-     *
-     * @param form the form of the current stage to fill out or the result of the
-     *      execution.
-     */
-    protected void setForm(DataForm form) {
-        data.setForm(form);
     }
 
     /**
@@ -210,12 +85,15 @@ public abstract class AdHocCommand {
      * command. It is invoked on every command. If there is a problem executing
      * the command it throws an XMPPException.
      *
+     * @return an ad-hoc command result.
      * @throws NoResponseException if there was no response from the remote entity.
      * @throws XMPPErrorException if there is an error executing the command.
      * @throws NotConnectedException if the XMPP connection is not connected.
      * @throws InterruptedException if the calling thread was interrupted.
      */
-    public abstract void execute() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+    public final AdHocCommandResult execute() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(AdHocCommandData.Action.execute);
+    }
 
     /**
      * Executes the next action of the command with the information provided in
@@ -224,13 +102,16 @@ public abstract class AdHocCommand {
      * or more stages. If there is a problem executing the command it throws an
      * XMPPException.
      *
-     * @param response the form answer of the previous stage.
+     * @param filledForm the form answer of the previous stage.
+     * @return an ad-hoc command result.
      * @throws NoResponseException if there was no response from the remote entity.
      * @throws XMPPErrorException if there is a problem executing the command.
      * @throws NotConnectedException if the XMPP connection is not connected.
      * @throws InterruptedException if the calling thread was interrupted.
      */
-    public abstract void next(FillableForm response) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+    public final AdHocCommandResult next(SubmitForm filledForm) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(AdHocCommandData.Action.next, filledForm.getDataForm());
+    }
 
     /**
      * Completes the command execution with the information provided in the
@@ -239,14 +120,16 @@ public abstract class AdHocCommand {
      * or more stages. If there is a problem executing the command it throws an
      * XMPPException.
      *
-     * @param response the form answer of the previous stage.
+     * @param filledForm the form answer of the previous stage.
-     *
+     * @return an ad-hoc command result.
      * @throws NoResponseException if there was no response from the remote entity.
      * @throws XMPPErrorException if there is a problem executing the command.
      * @throws NotConnectedException if the XMPP connection is not connected.
      * @throws InterruptedException if the calling thread was interrupted.
      */
-    public abstract void complete(FillableForm response) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+    public AdHocCommandResult complete(SubmitForm filledForm) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(AdHocCommandData.Action.complete, filledForm.getDataForm());
+    }
 
     /**
      * Goes to the previous stage. The requester is asking to re-send the
@@ -254,224 +137,70 @@ public abstract class AdHocCommand {
      * the previous one. If there is a problem executing the command it throws
      * an XMPPException.
      *
+     * @return an ad-hoc command result.
      * @throws NoResponseException if there was no response from the remote entity.
      * @throws XMPPErrorException if there is a problem executing the command.
      * @throws NotConnectedException if the XMPP connection is not connected.
      * @throws InterruptedException if the calling thread was interrupted.
      */
-    public abstract void prev() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+    public final AdHocCommandResult prev() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(AdHocCommandData.Action.prev);
+    }
 
     /**
-     * Cancels the execution of the command. This can be invoked on any stage of
+     * Executes the default action of the command with the information provided
-     * the execution. If there is a problem executing the command it throws an
+     * in the Form. This form must be the answer form of the previous stage. If
-     * XMPPException.
+     * there is a problem executing the command it throws an XMPPException.
      *
-     * @throws NoResponseException if there was no response from the remote entity.
+     * @param form the form answer of the previous stage.
-     * @throws XMPPErrorException if there is a problem executing the command.
+     * @return an ad-hoc command result.
+     * @throws XMPPErrorException if an error occurs.
+     * @throws NoResponseException if there was no response from the server.
      * @throws NotConnectedException if the XMPP connection is not connected.
      * @throws InterruptedException if the calling thread was interrupted.
      */
-    public abstract void cancel() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+    public final AdHocCommandResult execute(FillableForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(AdHocCommandData.Action.execute, form.getDataFormToSubmit());
+    }
+
+    private AdHocCommandResult executeAction(AdHocCommandData.Action action) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        return executeAction(action, null);
+    }
 
     /**
-     * Returns a collection with the allowed actions based on the current stage.
+     * Executes the <code>action</code> with the <code>form</code>.
-     * Possible actions are: {@link Action#prev prev}, {@link Action#next next} and
+     * The action could be any of the available actions. The form must
-     * {@link Action#complete complete}. This method will be only invoked for commands that
+     * be the answer of the previous stage. It can be <code>null</code> if it is the first stage.
-     * have one or more stages.
      *
-     * @return a collection with the allowed actions based on the current stage
+     * @param action the action to execute.
-     *      as defined in the SessionData.
+     * @param form the form with the information.
+     * @throws XMPPErrorException if there is a problem executing the command.
+     * @throws NoResponseException if there was no response from the server.
+     * @throws NotConnectedException if the XMPP connection is not connected.
+     * @throws InterruptedException if the calling thread was interrupted.
      */
-    protected List<Action> getActions() {
+    private synchronized AdHocCommandResult executeAction(AdHocCommandData.Action action, DataForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        return data.getActions();
+        AdHocCommandData request = AdHocCommandData.builder(getNode(), connection)
+                        .ofType(IQ.Type.set)
+                        .to(getOwnerJID())
+                        .setSessionId(getSessionId())
+                        .setAction(action)
+                        .setForm(form)
+                        .build();
+
+        addRequest(request);
+
+        AdHocCommandData response = connection.sendIqRequestAndWaitForResponse(request);
+
+        // The Ad-Hoc service ("server") may have generated a session id for us.
+        String sessionId = response.getSessionId();
+        if (sessionId != null) {
+            setSessionId(sessionId);
         }
 
-    /**
+        AdHocCommandResult result = AdHocCommandResult.from(response);
-     * Add an action to the current stage available actions. This should be used
+        addResult(result);
-     * when creating a response.
+        return result;
-     *
-     * @param action the action.
-     */
-    protected void addActionAvailable(Action action) {
-        data.addAction(action);
     }
 
-    /**
-     * Returns the action available for the current stage which is
-     * considered the equivalent to "execute". When the requester sends his
-     * reply, if no action was defined in the command then the action will be
-     * assumed "execute" thus assuming the action returned by this method. This
-     * method will never be invoked for commands that have no stages.
-     *
-     * @return the action available for the current stage which is considered
-     *      the equivalent to "execute".
-     */
-    protected Action getExecuteAction() {
-        return data.getExecuteAction();
-    }
-
-    /**
-     * Sets which of the actions available for the current stage is
-     * considered the equivalent to "execute". This should be used when setting
-     * a response. When the requester sends his reply, if no action was defined
-     * in the command then the action will be assumed "execute" thus assuming
-     * the action returned by this method.
-     *
-     * @param action the action.
-     */
-    protected void setExecuteAction(Action action) {
-        data.setExecuteAction(action);
-    }
-
-    /**
-     * Returns the status of the current stage.
-     *
-     * @return the current status.
-     */
-    public Status getStatus() {
-        return data.getStatus();
-    }
-
-    /**
-     * Check if this command has been completed successfully.
-     *
-     * @return <code>true</code> if this command is completed.
-     * @since 4.2
-     */
-    public boolean isCompleted() {
-        return getStatus() == Status.completed;
-    }
-
-    /**
-     * Sets the data of the current stage. This should not used.
-     *
-     * @param data the data.
-     */
-    void setData(AdHocCommandData data) {
-        this.data = data;
-    }
-
-    /**
-     * Gets the data of the current stage. This should not used.
-     *
-     * @return the data.
-     */
-    AdHocCommandData getData() {
-        return data;
-    }
-
-    /**
-     * Returns true if the <code>action</code> is available in the current stage.
-     * The {@link Action#cancel cancel} action is always allowed. To define the
-     * available actions use the <code>addActionAvailable</code> method.
-     *
-     * @param action TODO javadoc me please
-     *            The action to check if it is available.
-     * @return True if the action is available for the current stage.
-     */
-    protected boolean isValidAction(Action action) {
-        return getActions().contains(action) || Action.cancel.equals(action);
-    }
-
-    /**
-     * The status of the stage in the adhoc command.
-     */
-    public enum Status {
-
-        /**
-         * The command is being executed.
-         */
-        executing,
-
-        /**
-         * The command has completed. The command session has ended.
-         */
-        completed,
-
-        /**
-         * The command has been canceled. The command session has ended.
-         */
-        canceled
-    }
-
-    public enum Action {
-
-        /**
-         * The command should be executed or continue to be executed. This is
-         * the default value.
-         */
-        execute,
-
-        /**
-         * The command should be canceled.
-         */
-        cancel,
-
-        /**
-         * The command should be digress to the previous stage of execution.
-         */
-        prev,
-
-        /**
-         * The command should progress to the next stage of execution.
-         */
-        next,
-
-        /**
-         * The command should be completed (if possible).
-         */
-        complete,
-
-        /**
-         * The action is unknown. This is used when a received message has an
-         * unknown action. It must not be used to send an execution request.
-         */
-        unknown
-    }
-
-    public enum SpecificErrorCondition {
-
-        /**
-         * The responding JID cannot accept the specified action.
-         */
-        badAction("bad-action"),
-
-        /**
-         * The responding JID does not understand the specified action.
-         */
-        malformedAction("malformed-action"),
-
-        /**
-         * The responding JID cannot accept the specified language/locale.
-         */
-        badLocale("bad-locale"),
-
-        /**
-         * The responding JID cannot accept the specified payload (e.g. the data
-         * form did not provide one or more required fields).
-         */
-        badPayload("bad-payload"),
-
-        /**
-         * The responding JID cannot accept the specified sessionid.
-         */
-        badSessionid("bad-sessionid"),
-
-        /**
-         * The requesting JID specified a sessionid that is no longer active
-         * (either because it was completed, canceled, or timed out).
-         */
-        sessionExpired("session-expired");
-
-        private final String value;
-
-        SpecificErrorCondition(String value) {
-            this.value = value;
-        }
-
-        @Override
-        public String toString() {
-            return value;
-        }
-    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandHandler.java

@@ -0,0 +1,181 @@
+/**
+ *
+ * Copyright 2005-2007 Jive Software.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands;
+
+import org.jivesoftware.smack.SmackException.NoResponseException;
+import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.XMPPException.XMPPErrorException;
+import org.jivesoftware.smack.packet.StanzaError;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder;
+import org.jivesoftware.smackx.xdata.form.SubmitForm;
+
+import org.jxmpp.jid.Jid;
+
+/**
+ * Represents a command that can be executed locally from a remote location. This
+ * class must be extended to implement an specific ad-hoc command. This class
+ * provides some useful tools:<ul>
+ *      <li>Node</li>
+ *      <li>Name</li>
+ *      <li>Session ID</li>
+ *      <li>Current Stage</li>
+ *      <li>Available actions</li>
+ *      <li>Default action</li>
+ * </ul>
+ * To implement a new command extend this class and implement all the abstract
+ * methods. When implementing the actions remember that they could be invoked
+ * several times, and that you must use the current stage number to know what to
+ * do.
+ *
+ * @author Gabriel Guardincerri
+ * @author Florian Schmaus
+ */
+public abstract class AdHocCommandHandler extends AbstractAdHocCommand {
+
+    /**
+     * The time stamp of first invocation of the command. Used to implement the session timeout.
+     */
+    private final long creationDate;
+
+    /**
+     * The number of the current stage.
+     */
+    private int currentStage;
+
+    public AdHocCommandHandler(String node, String name, String sessionId) {
+        super(node, name);
+        setSessionId(sessionId);
+        this.creationDate = System.currentTimeMillis();
+    }
+
+    protected abstract AdHocCommandData execute(AdHocCommandDataBuilder response) throws NoResponseException,
+                    XMPPErrorException, NotConnectedException, InterruptedException, IllegalStateException;
+
+    protected abstract AdHocCommandData next(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                    throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException,
+                    IllegalStateException;
+
+    protected abstract AdHocCommandData complete(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                    throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException,
+                    IllegalStateException;
+
+    protected abstract AdHocCommandData prev(AdHocCommandDataBuilder response) throws NoResponseException,
+                    XMPPErrorException, NotConnectedException, InterruptedException, IllegalStateException;
+
+    /**
+     * Returns the date the command was created.
+     *
+     * @return the date the command was created.
+     */
+    public long getCreationDate() {
+        return creationDate;
+    }
+
+    /**
+     * Returns true if the specified requester has permission to execute all the
+     * stages of this action. This is checked when the first request is received,
+     * if the permission is grant then the requester will be able to execute
+     * all the stages of the command. It is not checked again during the
+     * execution.
+     *
+     * @param jid the JID to check permissions on.
+     * @return true if the user has permission to execute this action.
+     */
+    public boolean hasPermission(Jid jid) {
+        return true;
+    };
+
+    /**
+     * Returns the currently executing stage number. The first stage number is
+     * 1. During the execution of the first action this method will answer 1.
+     *
+     * @return the current stage number.
+     */
+    public final int getCurrentStage() {
+        return currentStage;
+    }
+
+    /**
+     * Increase the current stage number.
+     */
+    final void incrementStage() {
+        currentStage++;
+    }
+
+    /**
+     * Decrease the current stage number.
+     */
+    final void decrementStage() {
+        currentStage--;
+    }
+
+    protected static XMPPErrorException newXmppErrorException(StanzaError.Condition condition) {
+        return newXmppErrorException(condition, null);
+    }
+
+    protected static XMPPErrorException newXmppErrorException(StanzaError.Condition condition, String descriptiveText) {
+        StanzaError stanzaError = StanzaError.from(condition, descriptiveText).build();
+        return new XMPPErrorException(null, stanzaError);
+    }
+
+    protected static XMPPErrorException newBadRequestException(String descriptiveTest) {
+        return newXmppErrorException(StanzaError.Condition.bad_request, descriptiveTest);
+    }
+
+    public abstract static class SingleStage extends AdHocCommandHandler {
+
+        public SingleStage(String node, String name, String sessionId) {
+            super(node, name, sessionId);
+        }
+
+        protected abstract AdHocCommandData executeSingleStage(AdHocCommandDataBuilder response)
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException;
+
+        @Override
+        protected final AdHocCommandData execute(AdHocCommandDataBuilder response)
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+            response.setStatusCompleted();
+            return executeSingleStage(response);
+        }
+
+        @Override
+        public final AdHocCommandData next(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+            throw newXmppErrorException(StanzaError.Condition.bad_request);
+        }
+
+        @Override
+        public final AdHocCommandData complete(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+            throw newXmppErrorException(StanzaError.Condition.bad_request);
+        }
+
+        @Override
+        public final AdHocCommandData prev(AdHocCommandDataBuilder response)
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+            throw newXmppErrorException(StanzaError.Condition.bad_request);
+        }
+
+        @Override
+        public final void cancel()
+                        throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+            throw newXmppErrorException(StanzaError.Condition.bad_request);
+        }
+
+    }
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandHandlerFactory.java

@@ -19,28 +19,31 @@ package org.jivesoftware.smackx.commands;
 import java.lang.reflect.InvocationTargetException;
 
 /**
- * A factory for creating local commands. It's useful in cases where instantiation
+ * A factory for creating ad-hoc command handlers. It's useful in cases where instantiation
  * of a command is more complicated than just using the default constructor. For example,
  * when arguments must be passed into the constructor or when using a dependency injection
- * framework. When a LocalCommandFactory isn't used, you can provide the AdHocCommandManager
+ * framework. When a factory isn't used, you can provide the AdHocCommandManager
  * a Class object instead. For more details, see
- * {@link AdHocCommandManager#registerCommand(String, String, LocalCommandFactory)}.
+ * {@link AdHocCommandManager#registerCommand(String, String, AdHocCommandHandlerFactory)}.
  *
  * @author Matt Tucker
  */
-public interface LocalCommandFactory {
+public interface AdHocCommandHandlerFactory {
 
     /**
-     * Returns an instance of a LocalCommand.
+     * Returns a new instance of an ad-hoc command handler.
      *
+     * @param node the node of the ad-hoc command.
+     * @param name the name of the ad-hoc command.
+     * @param sessionId the session ID of the ad-hoc command.
      * @return a LocalCommand instance.
      * @throws InstantiationException if creating an instance failed.
      * @throws IllegalAccessException if creating an instance is not allowed.
-     * @throws SecurityException if there was a security violation.
-     * @throws NoSuchMethodException if no such method is declared
      * @throws InvocationTargetException if a reflection-based method or constructor invocation threw.
      * @throws IllegalArgumentException if an illegal argument was given.
      */
-    LocalCommand getInstance() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException;
+    AdHocCommandHandler create(String node, String name, String sessionId)
+                    throws InstantiationException, IllegalAccessException, IllegalArgumentException,
+                    InvocationTargetException;
 
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandManager.java

@@ -17,6 +17,7 @@
 
 package org.jivesoftware.smackx.commands;
 
+import java.lang.reflect.Constructor;
 import java.lang.reflect.InvocationTargetException;
 import java.util.ArrayList;
 import java.util.Collection;
@@ -44,16 +45,17 @@ import org.jivesoftware.smack.packet.IQ;
 import org.jivesoftware.smack.packet.StanzaError;
 import org.jivesoftware.smack.util.StringUtils;
 
-import org.jivesoftware.smackx.commands.AdHocCommand.Action;
-import org.jivesoftware.smackx.commands.AdHocCommand.Status;
 import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder;
 import org.jivesoftware.smackx.disco.AbstractNodeInformationProvider;
 import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
 import org.jivesoftware.smackx.disco.packet.DiscoverInfo;
 import org.jivesoftware.smackx.disco.packet.DiscoverItems;
-import org.jivesoftware.smackx.xdata.form.FillableForm;
+import org.jivesoftware.smackx.xdata.form.SubmitForm;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
+import org.jxmpp.jid.EntityFullJid;
 import org.jxmpp.jid.Jid;
 
 /**
@@ -65,6 +67,7 @@ import org.jxmpp.jid.Jid;
  * get an instance of this class.
  *
  * @author Gabriel Guardincerri
+ * @author Florian Schmaus
  */
 public final class AdHocCommandManager extends Manager {
     public static final String NAMESPACE = "http://jabber.org/protocol/commands";
@@ -74,7 +77,7 @@ public final class AdHocCommandManager extends Manager {
     /**
      * The session time out in seconds.
      */
-    private static final int SESSION_TIMEOUT = 2 * 60;
+    private static int DEFAULT_SESSION_TIMEOUT_SECS = 7 * 60;
 
     /**
      * Map an XMPPConnection with it AdHocCommandManager. This map have a key-value
@@ -91,7 +94,7 @@ public final class AdHocCommandManager extends Manager {
         XMPPConnectionRegistry.addConnectionCreationListener(new ConnectionCreationListener() {
             @Override
             public void connectionCreated(XMPPConnection connection) {
-                getAddHocCommandsManager(connection);
+                getInstance(connection);
             }
         });
     }
@@ -102,8 +105,21 @@ public final class AdHocCommandManager extends Manager {
      *
      * @param connection the XMPP connection.
      * @return the AdHocCommandManager associated with the connection.
+     * @deprecated use {@link #getInstance(XMPPConnection)} instead.
      */
-    public static synchronized AdHocCommandManager getAddHocCommandsManager(XMPPConnection connection) {
+    @Deprecated
+    public static AdHocCommandManager getAddHocCommandsManager(XMPPConnection connection) {
+        return getInstance(connection);
+    }
+
+    /**
+     * Returns the <code>AdHocCommandManager</code> related to the
+     * <code>connection</code>.
+     *
+     * @param connection the XMPP connection.
+     * @return the AdHocCommandManager associated with the connection.
+     */
+    public static synchronized AdHocCommandManager getInstance(XMPPConnection connection) {
         AdHocCommandManager ahcm = instances.get(connection);
         if (ahcm == null) {
             ahcm = new AdHocCommandManager(connection);
@@ -117,7 +133,8 @@ public final class AdHocCommandManager extends Manager {
      * Value=command. Command node matches the node attribute sent by command
      * requesters.
      */
-    private final Map<String, AdHocCommandInfo> commands = new ConcurrentHashMap<>();
+    // TODO: Change to Map once Smack's minimum Android API level is 24 or higher.
+    private final ConcurrentHashMap<String, AdHocCommandInfo> commands = new ConcurrentHashMap<>();
 
     /**
      * Map a command session ID with the instance LocalCommand. The LocalCommand
@@ -125,10 +142,12 @@ public final class AdHocCommandManager extends Manager {
      * the command execution. Note: Key=session ID, Value=LocalCommand. Session
      * ID matches the sessionid attribute sent by command responders.
      */
-    private final Map<String, LocalCommand> executingCommands = new ConcurrentHashMap<>();
+    private final Map<String, AdHocCommandHandler> executingCommands = new ConcurrentHashMap<>();
 
     private final ServiceDiscoveryManager serviceDiscoveryManager;
 
+    private int sessionTimeoutSecs = DEFAULT_SESSION_TIMEOUT_SECS;
+
     private AdHocCommandManager(XMPPConnection connection) {
         super(connection);
         this.serviceDiscoveryManager = ServiceDiscoveryManager.getInstanceFor(connection);
@@ -148,13 +167,17 @@ public final class AdHocCommandManager extends Manager {
                         new AbstractNodeInformationProvider() {
                             @Override
                             public List<DiscoverItems.Item> getNodeItems() {
-
                                 List<DiscoverItems.Item> answer = new ArrayList<>();
-                                Collection<AdHocCommandInfo> commandsList = getRegisteredCommands();
+                                Collection<AdHocCommandInfo> commandsList = commands.values();
+
+                                EntityFullJid ourJid = connection().getUser();
+                                if (ourJid == null) {
+                                    LOGGER.warning("Local connection JID not available, can not respond to " + NAMESPACE + " node information");
+                                    return null;
+                                }
 
                                 for (AdHocCommandInfo info : commandsList) {
-                                    DiscoverItems.Item item = new DiscoverItems.Item(
+                                    DiscoverItems.Item item = new DiscoverItems.Item(ourJid);
-                                            info.getOwnerJID());
                                     item.setName(info.getName());
                                     item.setNode(info.getNode());
                                     answer.add(item);
@@ -166,18 +189,17 @@ public final class AdHocCommandManager extends Manager {
 
         // The packet listener and the filter for processing some AdHoc Commands
         // Packets
+        // TODO: This handler being async means that requests for the same command could be handled out of order. Nobody
+        // complained so far, and I could imagine that it does not really matter in practice. But it is certainly
+        // something to keep in mind.
         connection.registerIQRequestHandler(new AbstractIqRequestHandler(AdHocCommandData.ELEMENT,
                         AdHocCommandData.NAMESPACE, IQ.Type.set, Mode.async) {
             @Override
             public IQ handleIQRequest(IQ iqRequest) {
                 AdHocCommandData requestData = (AdHocCommandData) iqRequest;
-                try {
+                AdHocCommandData response = processAdHocCommand(requestData);
-                    return processAdHocCommand(requestData);
+                assert response.getStatus() != null || response.getType() == IQ.Type.error;
-                }
+                return response;
-                catch (InterruptedException | NoResponseException | NotConnectedException e) {
-                    LOGGER.log(Level.INFO, "processAdHocCommand threw exception", e);
-                    return null;
-                }
             }
         });
     }
@@ -187,18 +209,21 @@ public final class AdHocCommandManager extends Manager {
      * connection. The <code>node</code> is an unique identifier of that command for
      * the connection related to this command manager. The <code>name</code> is the
      * human readable name of the command. The <code>class</code> is the class of
-     * the command, which must extend {@link LocalCommand} and have a default
+     * the command, which must extend {@link AdHocCommandHandler} and have a default
      * constructor.
      *
      * @param node the unique identifier of the command.
      * @param name the human readable name of the command.
-     * @param clazz the class of the command, which must extend {@link LocalCommand}.
+     * @param clazz the class of the command, which must extend {@link AdHocCommandHandler}.
+     * @throws SecurityException if there was a security violation.
+     * @throws NoSuchMethodException if no such method is declared.
      */
-    public void registerCommand(String node, String name, final Class<? extends LocalCommand> clazz) {
+    public void registerCommand(String node, String name, final Class<? extends AdHocCommandHandler> clazz) throws NoSuchMethodException, SecurityException {
-        registerCommand(node, name, new LocalCommandFactory() {
+        Constructor<? extends AdHocCommandHandler> constructor = clazz.getConstructor(String.class, String.class, String.class);
+        registerCommand(node, name, new AdHocCommandHandlerFactory() {
             @Override
-            public LocalCommand getInstance() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException  {
+            public AdHocCommandHandler create(String node, String name, String sessionId) throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException {
-                return clazz.getConstructor().newInstance();
+                return constructor.newInstance(node, name, sessionId);
             }
         });
     }
@@ -214,10 +239,12 @@ public final class AdHocCommandManager extends Manager {
      * @param name the human readable name of the command.
      * @param factory a factory to create new instances of the command.
      */
-    public void registerCommand(String node, final String name, LocalCommandFactory factory) {
+    public synchronized void registerCommand(String node, final String name, AdHocCommandHandlerFactory factory) {
-        AdHocCommandInfo commandInfo = new AdHocCommandInfo(node, name, connection().getUser(), factory);
+        AdHocCommandInfo commandInfo = new AdHocCommandInfo(node, name, factory);
+
+        AdHocCommandInfo existing = commands.putIfAbsent(node, commandInfo);
+        if (existing != null) throw new IllegalArgumentException("There is already an ad-hoc command registered for " + node);
 
-        commands.put(node, commandInfo);
         // Set the NodeInformationProvider that will provide information about
         // the added command
         serviceDiscoveryManager.setNodeInformationProvider(node,
@@ -242,6 +269,14 @@ public final class AdHocCommandManager extends Manager {
                 });
     }
 
+    public synchronized boolean unregisterCommand(String node) {
+        AdHocCommandInfo commandInfo = commands.remove(node);
+        if (commandInfo == null) return false;
+
+        serviceDiscoveryManager.removeNodeInformationProvider(node);
+        return true;
+    }
+
     /**
      * Discover the commands of an specific JID. The <code>jid</code> is a
      * full JID.
@@ -266,8 +301,8 @@ public final class AdHocCommandManager extends Manager {
      * @param node the identifier of the command
      * @return a local instance equivalent to the remote command.
      */
-    public RemoteCommand getRemoteCommand(Jid jid, String node) {
+    public AdHocCommand getRemoteCommand(Jid jid, String node) {
-        return new RemoteCommand(connection(), node, jid);
+        return new AdHocCommand(connection(), node, jid);
     }
 
     /**
@@ -291,240 +326,226 @@ public final class AdHocCommandManager extends Manager {
      *  <li>The action to execute is one of the available actions</li>
      * </ul>
      *
-     * @param requestData TODO javadoc me please
+     * @param request the incoming AdHoc command request.
-     *            the stanza to process.
-     * @throws NotConnectedException if the XMPP connection is not connected.
-     * @throws NoResponseException if there was no response from the remote entity.
-     * @throws InterruptedException if the calling thread was interrupted.
      */
-    private IQ processAdHocCommand(AdHocCommandData requestData) throws NoResponseException, NotConnectedException, InterruptedException {
+    private AdHocCommandData processAdHocCommand(AdHocCommandData request) {
-        // Creates the response with the corresponding data
+        String sessionId = request.getSessionId();
-        AdHocCommandData response = new AdHocCommandData();
-        response.setTo(requestData.getFrom());
-        response.setStanzaId(requestData.getStanzaId());
-        response.setNode(requestData.getNode());
-        response.setId(requestData.getTo());
-
-        String sessionId = requestData.getSessionID();
-        String commandNode = requestData.getNode();
 
+        final AdHocCommandHandler command;
         if (sessionId == null) {
+            String commandNode = request.getNode();
+
             // A new execution request has been received. Check that the
             // command exists
-            if (!commands.containsKey(commandNode)) {
+            AdHocCommandInfo commandInfo = commands.get(commandNode);
+            if (commandInfo == null) {
                 // Requested command does not exist so return
                 // item_not_found error.
-                return respondError(response, StanzaError.Condition.item_not_found);
+                return respondError(request, null, StanzaError.Condition.item_not_found);
             }
 
-            // Create new session ID
+            assert commandInfo.getNode().equals(commandNode);
-            sessionId = StringUtils.randomString(15);
 
-            try {
             // Create a new instance of the command with the
-                // corresponding sessionid
+            // corresponding session ID.
-                LocalCommand command;
             try {
-                    command = newInstanceOfCmd(commandNode, sessionId);
+                command = commandInfo.getCommandInstance();
             }
             catch (InstantiationException | IllegalAccessException | IllegalArgumentException
-                                | InvocationTargetException | NoSuchMethodException | SecurityException e) {
+                            | InvocationTargetException e) {
+                LOGGER.log(Level.WARNING, "Could not instanciate ad-hoc command server", e);
                 StanzaError xmppError = StanzaError.getBuilder()
                                 .setCondition(StanzaError.Condition.internal_server_error)
                                 .setDescriptiveEnText(e.getMessage())
                                 .build();
-                    return respondError(response, xmppError);
+                return respondError(request, null, xmppError);
             }
-
+        } else {
-                response.setType(IQ.Type.result);
+            command = executingCommands.get(sessionId);
-                command.setData(response);
-
-                // Check that the requester has enough permission.
-                // Answer forbidden error if requester permissions are not
-                // enough to execute the requested command
-                if (!command.hasPermission(requestData.getFrom())) {
-                    return respondError(response, StanzaError.Condition.forbidden);
-                }
-
-                Action action = requestData.getAction();
-
-                // If the action is unknown then respond an error.
-                if (action != null && action.equals(Action.unknown)) {
-                    return respondError(response, StanzaError.Condition.bad_request,
-                            AdHocCommand.SpecificErrorCondition.malformedAction);
-                }
-
-                // If the action is not execute, then it is an invalid action.
-                if (action != null && !action.equals(Action.execute)) {
-                    return respondError(response, StanzaError.Condition.bad_request,
-                            AdHocCommand.SpecificErrorCondition.badAction);
-                }
-
-                // Increase the state number, so the command knows in witch
-                // stage it is
-                command.incrementStage();
-                // Executes the command
-                command.execute();
-
-                if (command.isLastStage()) {
-                    // If there is only one stage then the command is completed
-                    response.setStatus(Status.completed);
-                }
-                else {
-                    // Else it is still executing, and is registered to be
-                    // available for the next call
-                    response.setStatus(Status.executing);
-                    executingCommands.put(sessionId, command);
-                    // See if the session sweeper thread is scheduled. If not, start it.
-                    maybeWindUpSessionSweeper();
-                }
-
-                // Sends the response packet
-                return response;
-
-            }
-            catch (XMPPErrorException e) {
-                // If there is an exception caused by the next, complete,
-                // prev or cancel method, then that error is returned to the
-                // requester.
-                StanzaError error = e.getStanzaError();
-
-                // If the error type is cancel, then the execution is
-                // canceled therefore the status must show that, and the
-                // command be removed from the executing list.
-                if (StanzaError.Type.CANCEL.equals(error.getType())) {
-                    response.setStatus(Status.canceled);
-                    executingCommands.remove(sessionId);
-                }
-                return respondError(response, error);
-            }
-        }
-        else {
-            LocalCommand command = executingCommands.get(sessionId);
-
             // Check that a command exists for the specified sessionID
             // This also handles if the command was removed in the meanwhile
             // of getting the key and the value of the map.
             if (command == null) {
-                return respondError(response, StanzaError.Condition.bad_request,
+                return respondError(request, null, StanzaError.Condition.bad_request,
-                        AdHocCommand.SpecificErrorCondition.badSessionid);
+                        SpecificErrorCondition.badSessionid);
+            }
         }
 
-            // Check if the Session data has expired (default is 10 minutes)
-            long creationStamp = command.getCreationDate();
-            if (System.currentTimeMillis() - creationStamp > SESSION_TIMEOUT * 1000) {
-                // Remove the expired session
-                executingCommands.remove(sessionId);
 
-                // Answer a not_allowed error (session-expired)
+        final AdHocCommandDataBuilder responseBuilder = AdHocCommandDataBuilder.buildResponseFor(request)
-                return respondError(response, StanzaError.Condition.not_allowed,
+                        .setSessionId(command.getSessionId());
-                        AdHocCommand.SpecificErrorCondition.sessionExpired);
-            }
 
+        final AdHocCommandData response;
         /*
          * Since the requester could send two requests for the same
          * executing command i.e. the same session id, all the execution of
          * the action must be synchronized to avoid inconsistencies.
          */
         synchronized (command) {
-                Action action = requestData.getAction();
+            command.addRequest(request);
 
-                // If the action is unknown the respond an error
+            if (sessionId == null) {
-                if (action != null && action.equals(Action.unknown)) {
+                response = processAdHocCommandOfNewSession(request, command, responseBuilder);
-                    return respondError(response, StanzaError.Condition.bad_request,
+            } else {
-                            AdHocCommand.SpecificErrorCondition.malformedAction);
+                response = processAdHocCommandOfExistingSession(request, command, responseBuilder);
             }
 
+
+            AdHocCommandResult commandResult = AdHocCommandResult.from(response);
+            command.addResult(commandResult);
+        }
+
+        return response;
+    }
+
+    private AdHocCommandData createResponseFrom(AdHocCommandData request, AdHocCommandDataBuilder response, XMPPErrorException exception, String sessionId) {
+        StanzaError error = exception.getStanzaError();
+
+        // If the error type is cancel, then the execution is
+        // canceled therefore the status must show that, and the
+        // command be removed from the executing list.
+        if (error.getType() == StanzaError.Type.CANCEL) {
+            response.setStatus(AdHocCommandData.Status.canceled);
+
+            executingCommands.remove(sessionId);
+
+            return response.build();
+        }
+
+        return respondError(request, response, error);
+    }
+
+    private static AdHocCommandData createResponseFrom(AdHocCommandData request, AdHocCommandDataBuilder response, Exception exception) {
+        StanzaError error = StanzaError.from(StanzaError.Condition.internal_server_error, exception.getMessage())
+                        .build();
+        return respondError(request, response, error);
+    }
+
+    private AdHocCommandData processAdHocCommandOfNewSession(AdHocCommandData request, AdHocCommandHandler command, AdHocCommandDataBuilder responseBuilder) {
+        // Check that the requester has enough permission.
+        // Answer forbidden error if requester permissions are not
+        // enough to execute the requested command
+        if (!command.hasPermission(request.getFrom())) {
+            return respondError(request, responseBuilder, StanzaError.Condition.forbidden);
+        }
+
+        AdHocCommandData.Action action = request.getAction();
+
+        // If the action is not execute, then it is an invalid action.
+        if (action != null && !action.equals(AdHocCommandData.Action.execute)) {
+            return respondError(request, responseBuilder, StanzaError.Condition.bad_request,
+                    SpecificErrorCondition.badAction);
+        }
+
+        // Increase the state number, so the command knows in witch
+        // stage it is
+        command.incrementStage();
+
+        final AdHocCommandData response;
+         try {
+            // Executes the command
+            response = command.execute(responseBuilder);
+        } catch (XMPPErrorException e) {
+            return createResponseFrom(request, responseBuilder, e, command.getSessionId());
+        } catch (NoResponseException | NotConnectedException | InterruptedException | IllegalStateException e) {
+            return createResponseFrom(request, responseBuilder, e);
+        }
+
+        if (response.isExecuting()) {
+            executingCommands.put(command.getSessionId(), command);
+            // See if the session sweeper thread is scheduled. If not, start it.
+            maybeWindUpSessionSweeper();
+        }
+
+        return response;
+    }
+
+    private AdHocCommandData processAdHocCommandOfExistingSession(AdHocCommandData request, AdHocCommandHandler command, AdHocCommandDataBuilder responseBuilder) {
+        // Check if the Session data has expired (default is 10 minutes)
+        long creationStamp = command.getCreationDate();
+        if (System.currentTimeMillis() - creationStamp > sessionTimeoutSecs * 1000) {
+            // Remove the expired session
+            executingCommands.remove(command.getSessionId());
+
+            // Answer a not_allowed error (session-expired)
+            return respondError(request, responseBuilder, StanzaError.Condition.not_allowed,
+                    SpecificErrorCondition.sessionExpired);
+        }
+
+        AdHocCommandData.Action action = request.getAction();
+
         // If the user didn't specify an action or specify the execute
         // action then follow the actual default execute action
-                if (action == null || Action.execute.equals(action)) {
+        if (action == null || AdHocCommandData.Action.execute.equals(action)) {
-                    action = command.getExecuteAction();
+            AllowedAction executeAction = command.getExecuteAction();
+            if (executeAction != null) {
+                action = executeAction.action;
+            }
         }
 
         // Check that the specified action was previously
         // offered
         if (!command.isValidAction(action)) {
-                    return respondError(response, StanzaError.Condition.bad_request,
+            return respondError(request, responseBuilder, StanzaError.Condition.bad_request,
-                            AdHocCommand.SpecificErrorCondition.badAction);
+                    SpecificErrorCondition.badAction);
         }
 
+        AdHocCommandData response;
         try {
-                    // TODO: Check that all the required fields of the form are
+           DataForm dataForm;
-                    // TODO: filled, if not throw an exception. This will simplify the
+           switch (action) {
-                    // TODO: construction of new commands
+           case next:
-
-                    // Since all errors were passed, the response is now a
-                    // result
-                    response.setType(IQ.Type.result);
-
-                    // Set the new data to the command.
-                    command.setData(response);
-
-                    if (Action.next.equals(action)) {
                command.incrementStage();
-                        DataForm dataForm = requestData.getForm();
+               dataForm = request.getForm();
-                        command.next(new FillableForm(dataForm));
+               response = command.next(responseBuilder, new SubmitForm(dataForm));
-                        if (command.isLastStage()) {
+               break;
-                            // If it is the last stage then the command is
+           case complete:
-                            // completed
-                            response.setStatus(Status.completed);
-                        }
-                        else {
-                            // Otherwise it is still executing
-                            response.setStatus(Status.executing);
-                        }
-                    }
-                    else if (Action.complete.equals(action)) {
                 command.incrementStage();
-                        DataForm dataForm = requestData.getForm();
+                dataForm = request.getForm();
-                        command.complete(new FillableForm(dataForm));
+                responseBuilder.setStatus(AdHocCommandData.Status.completed);
-                        response.setStatus(Status.completed);
+                response = command.complete(responseBuilder, new SubmitForm(dataForm));
                 // Remove the completed session
-                        executingCommands.remove(sessionId);
+                executingCommands.remove(command.getSessionId());
-                    }
+                break;
-                    else if (Action.prev.equals(action)) {
+            case prev:
                 command.decrementStage();
-                        command.prev();
+                response = command.prev(responseBuilder);
-                    }
+                break;
-                    else if (Action.cancel.equals(action)) {
+            case cancel:
                 command.cancel();
-                        response.setStatus(Status.canceled);
+                responseBuilder.setStatus(AdHocCommandData.Status.canceled);
+                response = responseBuilder.build();
                 // Remove the canceled session
-                        executingCommands.remove(sessionId);
+                executingCommands.remove(command.getSessionId());
+                break;
+            default:
+                return respondError(request, responseBuilder, StanzaError.Condition.bad_request,
+                                SpecificErrorCondition.badAction);
+            }
+        } catch (XMPPErrorException e) {
+            return createResponseFrom(request, responseBuilder, e, command.getSessionId());
+        } catch (NoResponseException | NotConnectedException | InterruptedException | IllegalStateException e) {
+            return createResponseFrom(request, responseBuilder, e);
         }
 
         return response;
     }
-                catch (XMPPErrorException e) {
-                    // If there is an exception caused by the next, complete,
-                    // prev or cancel method, then that error is returned to the
-                    // requester.
-                    StanzaError error = e.getStanzaError();
-
-                    // If the error type is cancel, then the execution is
-                    // canceled therefore the status must show that, and the
-                    // command be removed from the executing list.
-                    if (StanzaError.Type.CANCEL.equals(error.getType())) {
-                        response.setStatus(Status.canceled);
-                        executingCommands.remove(sessionId);
-                    }
-                    return respondError(response, error);
-                }
-            }
-        }
-    }
 
     private boolean sessionSweeperScheduled;
 
+    private int getSessionRemovalTimeoutSecs() {
+        return sessionTimeoutSecs * 2;
+    }
+
     private void sessionSweeper() {
         final long currentTime = System.currentTimeMillis();
         synchronized (this) {
-            for (Iterator<Map.Entry<String, LocalCommand>> it = executingCommands.entrySet().iterator(); it.hasNext();) {
+            for (Iterator<Map.Entry<String, AdHocCommandHandler>> it = executingCommands.entrySet().iterator(); it.hasNext();) {
-                Map.Entry<String, LocalCommand> entry = it.next();
+                Map.Entry<String, AdHocCommandHandler> entry = it.next();
-                LocalCommand command = entry.getValue();
+                AdHocCommandHandler command = entry.getValue();
 
                 long creationStamp = command.getCreationDate();
-                // Check if the Session data has expired (default is 10 minutes)
+                // Check if the Session data has expired.
                 // To remove it from the session list it waits for the double of
                 // the of time out time. This is to let
                 // the requester know why his execution request is
@@ -532,7 +553,7 @@ public final class AdHocCommandManager extends Manager {
                 // after the time out, then once the user requests to
                 // continue the execution he will received an
                 // invalid session error and not a time out error.
-                if (currentTime - creationStamp > SESSION_TIMEOUT * 1000 * 2) {
+                if (currentTime - creationStamp > getSessionRemovalTimeoutSecs() * 1000) {
                     // Remove the expired session
                     it.remove();
                 }
@@ -552,104 +573,100 @@ public final class AdHocCommandManager extends Manager {
         }
 
         sessionSweeperScheduled = true;
-        schedule(this::sessionSweeper, 10, TimeUnit.SECONDS);
+        schedule(this::sessionSweeper, getSessionRemovalTimeoutSecs() + 1, TimeUnit.SECONDS);
     }
 
     /**
      * Responds an error with an specific condition.
      *
-     * @param response the response to send.
+     * @param request the request that caused the error response.
      * @param condition the condition of the error.
      */
-    private static IQ respondError(AdHocCommandData response,
+    private static AdHocCommandData respondError(AdHocCommandData request, AdHocCommandDataBuilder response,
             StanzaError.Condition condition) {
-        return respondError(response, StanzaError.getBuilder(condition).build());
+        return respondError(request, response, StanzaError.getBuilder(condition).build());
     }
 
     /**
      * Responds an error with an specific condition.
      *
-     * @param response the response to send.
+     * @param request the request that caused the error response.
      * @param condition the condition of the error.
      * @param specificCondition the adhoc command error condition.
      */
-    private static IQ respondError(AdHocCommandData response, StanzaError.Condition condition,
+    private static AdHocCommandData respondError(AdHocCommandData request, AdHocCommandDataBuilder response, StanzaError.Condition condition,
-            AdHocCommand.SpecificErrorCondition specificCondition) {
+            SpecificErrorCondition specificCondition) {
         StanzaError error = StanzaError.getBuilder(condition)
                         .addExtension(new AdHocCommandData.SpecificError(specificCondition))
                         .build();
-        return respondError(response, error);
+        return respondError(request, response, error);
     }
 
     /**
      * Responds an error with an specific error.
      *
-     * @param response the response to send.
+     * @param request the request that caused the error response.
      * @param error the error to send.
      */
-    private static IQ respondError(AdHocCommandData response, StanzaError error) {
+    private static AdHocCommandData respondError(AdHocCommandData request, AdHocCommandDataBuilder response, StanzaError error) {
-        response.setType(IQ.Type.error);
+        if (response == null) {
-        response.setError(error);
+            return AdHocCommandDataBuilder.buildResponseFor(request, IQ.ResponseType.error).setError(error).build();
-        return response;
         }
 
-    /**
+        // Response may be not of IQ type error here, so switch that.
-     * Creates a new instance of a command to be used by a new execution request
+        return response.ofType(IQ.Type.error)
-     *
+            .setError(error)
-     * @param commandNode the command node that identifies it.
+            .build();
-     * @param sessionID the session id of this execution.
-     * @return the command instance to execute.
-     * @throws XMPPErrorException if there is problem creating the new instance.
-     * @throws SecurityException if there was a security violation.
-     * @throws NoSuchMethodException if no such method is declared
-     * @throws InvocationTargetException if a reflection-based method or constructor invocation threw.
-     * @throws IllegalArgumentException if an illegal argument was given.
-     * @throws IllegalAccessException in case of an illegal access.
-     * @throws InstantiationException in case of an instantiation error.
-     */
-    private LocalCommand newInstanceOfCmd(String commandNode, String sessionID)
-                    throws XMPPErrorException, InstantiationException, IllegalAccessException, IllegalArgumentException,
-                    InvocationTargetException, NoSuchMethodException, SecurityException {
-        AdHocCommandInfo commandInfo = commands.get(commandNode);
-        LocalCommand command = commandInfo.getCommandInstance();
-        command.setSessionID(sessionID);
-        command.setName(commandInfo.getName());
-        command.setNode(commandInfo.getNode());
-
-        return command;
     }
 
-    /**
+    public static void setDefaultSessionTimeoutSecs(int seconds) {
-     * Returns the registered commands of this command manager, which is related
+        if (seconds < 10) {
-     * to a connection.
+            throw new IllegalArgumentException();
-     *
+        }
-     * @return the registered commands.
+        DEFAULT_SESSION_TIMEOUT_SECS = seconds;
-     */
+    }
-    private Collection<AdHocCommandInfo> getRegisteredCommands() {
+
-        return commands.values();
+    public void setSessionTimeoutSecs(int seconds) {
+        if (seconds < 10) {
+            throw new IllegalArgumentException();
+        }
+
+        sessionTimeoutSecs = seconds;
     }
 
     /**
      * Stores ad-hoc command information.
      */
-    private static final class AdHocCommandInfo {
+    private final class AdHocCommandInfo {
 
-        private String node;
+        private final String node;
-        private String name;
+        private final String name;
-        private final Jid ownerJID;
+        private final AdHocCommandHandlerFactory factory;
-        private LocalCommandFactory factory;
 
-        private AdHocCommandInfo(String node, String name, Jid ownerJID,
+        private static final int MAX_SESSION_GEN_ATTEMPTS = 3;
-                LocalCommandFactory factory) {
+
+        private AdHocCommandInfo(String node, String name, AdHocCommandHandlerFactory factory) {
             this.node = node;
             this.name = name;
-            this.ownerJID = ownerJID;
             this.factory = factory;
         }
 
-        public LocalCommand getCommandInstance() throws InstantiationException,
+        public AdHocCommandHandler getCommandInstance() throws InstantiationException,
-                IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException {
+                IllegalAccessException, IllegalArgumentException, InvocationTargetException {
-            return factory.getInstance();
+            String sessionId;
+            // TODO: The code below contains a race condition. Use CopncurrentHashMap.computeIfAbsent() to remove the
+            // race condition once Smack's minimum Android API level 24 or higher.
+            int attempt = 0;
+            do {
+                attempt++;
+                if (attempt > MAX_SESSION_GEN_ATTEMPTS) {
+                    throw new RuntimeException("Failed to compute unique session ID");
+                }
+                // Create new session ID
+                sessionId = StringUtils.randomString(15);
+            } while (executingCommands.containsKey(sessionId));
+
+            return factory.create(node, name, sessionId);
         }
 
         public String getName() {
@@ -660,8 +677,5 @@ public final class AdHocCommandManager extends Manager {
             return node;
         }
 
-        public Jid getOwnerJID() {
-            return ownerJID;
-        }
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandResult.java

@@ -0,0 +1,102 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands;
+
+import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.xdata.form.FillableForm;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+// TODO: Make this a sealed class once Smack is Java 17 or higher.
+public abstract class AdHocCommandResult {
+
+    private final AdHocCommandData response;
+    private final boolean completed;
+
+    private AdHocCommandResult(AdHocCommandData response, boolean completed) {
+        this.response = response;
+        this.completed = completed;
+    }
+
+    public final AdHocCommandData getResponse() {
+        return response;
+    }
+
+    public final boolean isCompleted() {
+        return completed;
+    }
+
+    public StatusExecuting asExecutingOrThrow() {
+        if (this instanceof StatusExecuting)
+            return (StatusExecuting) this;
+
+        throw new IllegalStateException();
+    }
+
+    public StatusCompleted asCompletedOrThrow() {
+        if (this instanceof StatusCompleted)
+            return (StatusCompleted) this;
+
+        throw new IllegalStateException();
+    }
+
+    public static final class StatusExecuting extends AdHocCommandResult {
+        private StatusExecuting(AdHocCommandData response) {
+            super(response, false);
+            assert response.getStatus() == AdHocCommandData.Status.executing;
+        }
+
+        public FillableForm getFillableForm() {
+            DataForm form = getResponse().getForm();
+            return new FillableForm(form);
+        }
+    }
+
+    public static final class StatusCompleted extends AdHocCommandResult {
+        private StatusCompleted(AdHocCommandData response) {
+            super(response, true);
+            assert response.getStatus() == AdHocCommandData.Status.completed;
+        }
+    }
+
+    /**
+     * This subclass is only used internally by Smack.
+     */
+    @SuppressWarnings("JavaLangClash")
+    static final class Error extends AdHocCommandResult {
+        private Error(AdHocCommandData response) {
+            super(response, false);
+        }
+    }
+
+    public static AdHocCommandResult from(AdHocCommandData response) {
+        IQ.Type iqType = response.getType();
+        if (iqType == IQ.Type.error)
+            return new Error(response);
+
+        assert iqType == IQ.Type.result;
+
+        switch (response.getStatus()) {
+        case executing:
+            return new StatusExecuting(response);
+        case completed:
+            return new StatusCompleted(response);
+        default:
+            throw new IllegalArgumentException();
+        }
+    }
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/LocalCommand.java

@@ -1,168 +0,0 @@
-/**
- *
- * Copyright 2005-2007 Jive Software.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package org.jivesoftware.smackx.commands;
-
-import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
-
-import org.jxmpp.jid.Jid;
-
-/**
- * Represents a command that can be executed locally from a remote location. This
- * class must be extended to implement an specific ad-hoc command. This class
- * provides some useful tools:<ul>
- *      <li>Node</li>
- *      <li>Name</li>
- *      <li>Session ID</li>
- *      <li>Current Stage</li>
- *      <li>Available actions</li>
- *      <li>Default action</li>
- * </ul>
- * To implement a new command extend this class and implement all the abstract
- * methods. When implementing the actions remember that they could be invoked
- * several times, and that you must use the current stage number to know what to
- * do.
- *
- * @author Gabriel Guardincerri
- */
-public abstract class LocalCommand extends AdHocCommand {
-
-    /**
-     * The time stamp of first invocation of the command. Used to implement the session timeout.
-     */
-    private final long creationDate;
-
-    /**
-     * The unique ID of the execution of the command.
-     */
-    private String sessionID;
-
-    /**
-     * The full JID of the host of the command.
-     */
-    private Jid ownerJID;
-
-    /**
-     * The number of the current stage.
-     */
-    private int currentStage;
-
-    public LocalCommand() {
-        super();
-        this.creationDate = System.currentTimeMillis();
-        currentStage = -1;
-    }
-
-    /**
-     * The sessionID is an unique identifier of an execution request. This is
-     * automatically handled and should not be called.
-     *
-     * @param sessionID the unique session id of this execution
-     */
-    public void setSessionID(String sessionID) {
-        this.sessionID = sessionID;
-        getData().setSessionID(sessionID);
-    }
-
-    /**
-     * Returns the session ID of this execution.
-     *
-     * @return the unique session id of this execution
-     */
-    public String getSessionID() {
-        return sessionID;
-    }
-
-    /**
-     * Sets the JID of the command host. This is automatically handled and should
-     * not be called.
-     *
-     * @param ownerJID the JID of the owner.
-     */
-    public void setOwnerJID(Jid ownerJID) {
-        this.ownerJID = ownerJID;
-    }
-
-    @Override
-    public Jid getOwnerJID() {
-        return ownerJID;
-    }
-
-    /**
-     * Returns the date the command was created.
-     *
-     * @return the date the command was created.
-     */
-    public long getCreationDate() {
-        return creationDate;
-    }
-
-    /**
-     * Returns true if the current stage is the last one. If it is then the
-     * execution of some action will complete the execution of the command.
-     * Commands that don't have multiple stages can always return <code>true</code>.
-     *
-     * @return true if the command is in the last stage.
-     */
-    public abstract boolean isLastStage();
-
-    /**
-     * Returns true if the specified requester has permission to execute all the
-     * stages of this action. This is checked when the first request is received,
-     * if the permission is grant then the requester will be able to execute
-     * all the stages of the command. It is not checked again during the
-     * execution.
-     *
-     * @param jid the JID to check permissions on.
-     * @return true if the user has permission to execute this action.
-     */
-    public abstract boolean hasPermission(Jid jid);
-
-    /**
-     * Returns the currently executing stage number. The first stage number is
-     * 0. During the execution of the first action this method will answer 0.
-     *
-     * @return the current stage number.
-     */
-    public int getCurrentStage() {
-        return currentStage;
-    }
-
-    @Override
-    void setData(AdHocCommandData data) {
-        data.setSessionID(sessionID);
-        super.setData(data);
-    }
-
-    /**
-     * Increase the current stage number. This is automatically handled and should
-     * not be called.
-     *
-     */
-    void incrementStage() {
-        currentStage++;
-    }
-
-    /**
-     * Decrease the current stage number. This is automatically handled and should
-     * not be called.
-     *
-     */
-    void decrementStage() {
-        currentStage--;
-    }
-}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/RemoteCommand.java

@@ -1,164 +0,0 @@
-/**
- *
- * Copyright 2005-2007 Jive Software.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package org.jivesoftware.smackx.commands;
-
-import org.jivesoftware.smack.SmackException.NoResponseException;
-import org.jivesoftware.smack.SmackException.NotConnectedException;
-import org.jivesoftware.smack.XMPPConnection;
-import org.jivesoftware.smack.XMPPException.XMPPErrorException;
-import org.jivesoftware.smack.packet.IQ;
-
-import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
-import org.jivesoftware.smackx.xdata.form.FillableForm;
-import org.jivesoftware.smackx.xdata.packet.DataForm;
-
-import org.jxmpp.jid.Jid;
-
-/**
- * Represents a command that is in a remote location. Invoking one of the
- * {@link AdHocCommand.Action#execute execute}, {@link AdHocCommand.Action#next next},
- * {@link AdHocCommand.Action#prev prev}, {@link AdHocCommand.Action#cancel cancel} or
- * {@link AdHocCommand.Action#complete complete} actions results in executing that
- * action in the remote location. In response to that action the internal state
- * of the this command instance will change. For example, if the command is a
- * single stage command, then invoking the execute action will execute this
- * action in the remote location. After that the local instance will have a
- * state of "completed" and a form or notes that applies.
- *
- * @author Gabriel Guardincerri
- *
- */
-public class RemoteCommand extends AdHocCommand {
-
-    /**
-     * The connection that is used to execute this command
-     */
-    private final XMPPConnection connection;
-
-    /**
-     * The full JID of the command host
-     */
-    private final Jid jid;
-
-    /**
-     * The session ID of this execution.
-     */
-    private String sessionID;
-
-    /**
-     * Creates a new RemoteCommand that uses an specific connection to execute a
-     * command identified by <code>node</code> in the host identified by
-     * <code>jid</code>
-     *
-     * @param connection the connection to use for the execution.
-     * @param node the identifier of the command.
-     * @param jid the JID of the host.
-     */
-    protected RemoteCommand(XMPPConnection connection, String node, Jid jid) {
-        super();
-        this.connection = connection;
-        this.jid = jid;
-        this.setNode(node);
-    }
-
-    @Override
-    public void cancel() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.cancel);
-    }
-
-    @Override
-    public void complete(FillableForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.complete, form.getDataFormToSubmit());
-    }
-
-    @Override
-    public void execute() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.execute);
-    }
-
-    /**
-     * Executes the default action of the command with the information provided
-     * in the Form. This form must be the answer form of the previous stage. If
-     * there is a problem executing the command it throws an XMPPException.
-     *
-     * @param form the form answer of the previous stage.
-     * @throws XMPPErrorException if an error occurs.
-     * @throws NoResponseException if there was no response from the server.
-     * @throws NotConnectedException if the XMPP connection is not connected.
-     * @throws InterruptedException if the calling thread was interrupted.
-     */
-    public void execute(FillableForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.execute, form.getDataFormToSubmit());
-    }
-
-    @Override
-    public void next(FillableForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.next, form.getDataFormToSubmit());
-    }
-
-    @Override
-    public void prev() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(Action.prev);
-    }
-
-    private void executeAction(Action action) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        executeAction(action, null);
-    }
-
-    /**
-     * Executes the <code>action</code> with the <code>form</code>.
-     * The action could be any of the available actions. The form must
-     * be the answer of the previous stage. It can be <code>null</code> if it is the first stage.
-     *
-     * @param action the action to execute.
-     * @param form the form with the information.
-     * @throws XMPPErrorException if there is a problem executing the command.
-     * @throws NoResponseException if there was no response from the server.
-     * @throws NotConnectedException if the XMPP connection is not connected.
-     * @throws InterruptedException if the calling thread was interrupted.
-     */
-    private void executeAction(Action action, DataForm form) throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
-        // TODO: Check that all the required fields of the form were filled, if
-        // TODO: not throw the corresponding exception. This will make a faster response,
-        // TODO: since the request is stopped before it's sent.
-        AdHocCommandData data = new AdHocCommandData();
-        data.setType(IQ.Type.set);
-        data.setTo(getOwnerJID());
-        data.setNode(getNode());
-        data.setSessionID(sessionID);
-        data.setAction(action);
-        data.setForm(form);
-
-        AdHocCommandData responseData = null;
-        try {
-            responseData = connection.sendIqRequestAndWaitForResponse(data);
-        }
-        finally {
-            // We set the response data in a 'finally' block, so that it also gets set even if an error IQ was returned.
-            if (responseData != null) {
-                this.sessionID = responseData.getSessionID();
-                super.setData(responseData);
-            }
-        }
-
-    }
-
-    @Override
-    public Jid getOwnerJID() {
-        return jid;
-    }
-}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/SpecificErrorCondition.java

@@ -0,0 +1,63 @@
+/**
+ *
+ * Copyright 2005-2007 Jive Software.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands;
+
+public enum SpecificErrorCondition {
+
+    /**
+     * The responding JID cannot accept the specified action.
+     */
+    badAction("bad-action"),
+
+    /**
+     * The responding JID does not understand the specified action.
+     */
+    malformedAction("malformed-action"),
+
+    /**
+     * The responding JID cannot accept the specified language/locale.
+     */
+    badLocale("bad-locale"),
+
+    /**
+     * The responding JID cannot accept the specified payload (e.g. the data
+     * form did not provide one or more required fields).
+     */
+    badPayload("bad-payload"),
+
+    /**
+     * The responding JID cannot accept the specified sessionid.
+     */
+    badSessionid("bad-sessionid"),
+
+    /**
+     * The requesting JID specified a sessionid that is no longer active
+     * (either because it was completed, canceled, or timed out).
+     */
+    sessionExpired("session-expired");
+
+    private final String value;
+
+    SpecificErrorCondition(String value) {
+        this.value = value;
+    }
+
+    @Override
+    public String toString() {
+        return value;
+    }
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/packet/AdHocCommandData.java

@@ -18,63 +18,114 @@
 package org.jivesoftware.smackx.commands.packet;
 
 import java.util.ArrayList;
+import java.util.EnumSet;
 import java.util.List;
+import java.util.Set;
 
+import org.jivesoftware.smack.XMPPConnection;
 import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.packet.IqData;
 import org.jivesoftware.smack.packet.XmlElement;
 
-import org.jivesoftware.smackx.commands.AdHocCommand;
-import org.jivesoftware.smackx.commands.AdHocCommand.Action;
-import org.jivesoftware.smackx.commands.AdHocCommand.SpecificErrorCondition;
 import org.jivesoftware.smackx.commands.AdHocCommandNote;
+import org.jivesoftware.smackx.commands.SpecificErrorCondition;
 import org.jivesoftware.smackx.xdata.packet.DataForm;
 
-import org.jxmpp.jid.Jid;
-
 /**
  * Represents the state and the request of the execution of an adhoc command.
  *
  * @author Gabriel Guardincerri
+ * @author Florian Schmaus
  */
-public class AdHocCommandData extends IQ {
+public class AdHocCommandData extends IQ implements AdHocCommandDataView {
 
     public static final String ELEMENT = "command";
     public static final String NAMESPACE = "http://jabber.org/protocol/commands";
 
-    /* JID of the command host */
+    private final String node;
-    private Jid id;
 
-    /* Command name */
+    private final String name;
-    private String name;
 
-    /* Command identifier */
+    private final String sessionId;
-    private String node;
-
-    /* Unique ID of the execution */
-    private String sessionID;
 
     private final List<AdHocCommandNote> notes = new ArrayList<>();
 
-    private DataForm form;
+    private final DataForm form;
 
-    /* Action request to be executed */
+    private final Action action;
-    private AdHocCommand.Action action;
 
-    /* Current execution status */
+    private final Status status;
-    private AdHocCommand.Status status;
 
-    private final ArrayList<AdHocCommand.Action> actions = new ArrayList<>();
+    private final Set<AllowedAction> actions = EnumSet.noneOf(AllowedAction.class);
 
-    private AdHocCommand.Action executeAction;
+    private final AllowedAction executeAction;
 
-    public AdHocCommandData() {
+    public AdHocCommandData(AdHocCommandDataBuilder builder) {
-        super(ELEMENT, NAMESPACE);
+        super(builder, ELEMENT, NAMESPACE);
+        node = builder.getNode();
+        name = builder.getName();
+        sessionId = builder.getSessionId();
+        notes.addAll(builder.getNotes());
+        form = builder.getForm();
+        action = builder.getAction();
+        status = builder.getStatus();
+        actions.addAll(builder.getActions());
+        executeAction = builder.getExecuteAction();
+
+        if (executeAction != null && !actions.contains(executeAction)) {
+            throw new IllegalArgumentException("Execute action " + executeAction + " is not part of allowed actions: " + actions);
+        }
+    }
+
+    @Override
+    public String getNode() {
+        return node;
+    }
+
+   @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String getSessionId() {
+        return sessionId;
+    }
+
+    @Override
+    public List<AdHocCommandNote> getNotes() {
+        return notes;
+    }
+
+    @Override
+    public DataForm getForm() {
+        return form;
+    }
+
+    @Override
+    public Action getAction() {
+        return action;
+    }
+
+    @Override
+    public Status getStatus() {
+        return status;
+    }
+
+    @Override
+    public Set<AllowedAction> getActions() {
+        return actions;
+    }
+
+    @Override
+    public AllowedAction getExecuteAction() {
+        return executeAction;
     }
 
     @Override
     protected IQChildElementXmlStringBuilder getIQChildElementBuilder(IQChildElementXmlStringBuilder xml) {
         xml.attribute("node", node);
-        xml.optAttribute("sessionid", sessionID);
+        xml.optAttribute("sessionid", sessionId);
         xml.optAttribute("status", status);
         xml.optAttribute("action", action);
         xml.rightAngleBracket();
@@ -87,19 +138,19 @@ public class AdHocCommandData extends IQ {
             } else {
                 xml.rightAngleBracket();
 
-                for (AdHocCommand.Action action : actions) {
+                for (AdHocCommandData.AllowedAction action : actions) {
                     xml.emptyElement(action);
                 }
                 xml.closeElement("actions");
             }
         }
 
-        if (form != null) {
+        xml.optAppend(form);
-            xml.append(form.toXML());
-        }
 
         for (AdHocCommandNote note : notes) {
-            xml.halfOpenElement("note").attribute("type", note.getType().toString()).rightAngleBracket();
+            xml.halfOpenElement("note")
+              .attribute("type", note.getType().toString())
+              .rightAngleBracket();
             xml.append(note.getValue());
             xml.closeElement("note");
         }
@@ -112,132 +163,16 @@ public class AdHocCommandData extends IQ {
         return xml;
     }
 
-    /**
+    public static AdHocCommandDataBuilder builder(String node, IqData iqCommon) {
-     * Returns the JID of the command host.
+        return new AdHocCommandDataBuilder(node, iqCommon);
-     *
-     * @return the JID of the command host.
-     */
-    public Jid getId() {
-        return id;
     }
 
-    public void setId(Jid id) {
+    public static AdHocCommandDataBuilder builder(String node, String stanzaId) {
-        this.id = id;
+        return new AdHocCommandDataBuilder(node, stanzaId);
     }
 
-    /**
+    public static AdHocCommandDataBuilder builder(String node, XMPPConnection connection) {
-     * Returns the human name of the command.
+        return new AdHocCommandDataBuilder(node, connection);
-     *
-     * @return the name of the command.
-     */
-    public String getName() {
-        return name;
-    }
-
-    public void setName(String name) {
-        this.name = name;
-    }
-
-    /**
-     * Returns the identifier of the command.
-     *
-     * @return the node.
-     */
-    public String getNode() {
-        return node;
-    }
-
-    public void setNode(String node) {
-        this.node = node;
-    }
-
-    /**
-     * Returns the list of notes that the command has.
-     *
-     * @return the notes.
-     */
-    public List<AdHocCommandNote> getNotes() {
-        return notes;
-    }
-
-    public void addNote(AdHocCommandNote note) {
-        this.notes.add(note);
-    }
-
-    public void removeNote(AdHocCommandNote note) {
-        this.notes.remove(note);
-    }
-
-    /**
-     * Returns the form of the command.
-     *
-     * @return the data form associated with the command.
-     */
-    public DataForm getForm() {
-        return form;
-    }
-
-    public void setForm(DataForm form) {
-        this.form = form;
-    }
-
-    /**
-     * Returns the action to execute. The action is set only on a request.
-     *
-     * @return the action to execute.
-     */
-    public AdHocCommand.Action getAction() {
-        return action;
-    }
-
-    public void setAction(AdHocCommand.Action action) {
-        this.action = action;
-    }
-
-    /**
-     * Returns the status of the execution.
-     *
-     * @return the status.
-     */
-    public AdHocCommand.Status getStatus() {
-        return status;
-    }
-
-    public void setStatus(AdHocCommand.Status status) {
-        this.status = status;
-    }
-
-    public List<Action> getActions() {
-        return actions;
-    }
-
-    public void addAction(Action action) {
-        actions.add(action);
-    }
-
-    public void setExecuteAction(Action executeAction) {
-        this.executeAction = executeAction;
-    }
-
-    public Action getExecuteAction() {
-        return executeAction;
-    }
-
-    /**
-     * Set the 'sessionid' attribute of the command.
-     * <p>
-     * This value can be null or empty for the first command, but MUST be set for subsequent commands. See also <a
-     * href="http://xmpp.org/extensions/xep-0050.html#impl-session">XEP-0050 § 3.3 Session Lifetime</a>.
-     * </p>
-     *
-     * @param sessionID TODO javadoc me please
-     */
-    public void setSessionID(String sessionID) {
-        this.sessionID = sessionID;
-    }
-
-    public String getSessionID() {
-        return sessionID;
     }
 
     public static class SpecificError implements XmlElement {
@@ -271,4 +206,86 @@ public class AdHocCommandData extends IQ {
             return buf.toString();
         }
     }
+
+    /**
+     * The status of the stage in the adhoc command.
+     */
+    public enum Status {
+
+        /**
+         * The command is being executed.
+         */
+        executing,
+
+        /**
+         * The command has completed. The command session has ended.
+         */
+        completed,
+
+        /**
+         * The command has been canceled. The command session has ended.
+         */
+        canceled
+    }
+
+    public enum AllowedAction {
+
+        /**
+         * The command should be digress to the previous stage of execution.
+         */
+        prev(Action.prev),
+
+        /**
+         * The command should progress to the next stage of execution.
+         */
+        next(Action.next),
+
+        /**
+         * The command should be completed (if possible).
+         */
+        complete(Action.complete),
+        ;
+
+        public final Action action;
+
+        AllowedAction(Action action) {
+            this.action = action;
+        }
+    }
+
+    public enum Action {
+        /**
+         * The command should be executed or continue to be executed. This is
+         * the default value.
+         */
+        execute(null),
+
+        /**
+         * The command should be canceled.
+         */
+        cancel(null),
+
+        /**
+         * The command should be digress to the previous stage of execution.
+         */
+        prev(AllowedAction.prev),
+
+        /**
+         * The command should progress to the next stage of execution.
+         */
+        next(AllowedAction.next),
+
+        /**
+         * The command should be completed (if possible).
+         */
+        complete(AllowedAction.complete),
+        ;
+
+        public final AllowedAction allowedAction;
+
+        Action(AllowedAction allowedAction) {
+            this.allowedAction = allowedAction;
+        }
+
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/packet/AdHocCommandDataBuilder.java

@@ -0,0 +1,220 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands.packet;
+
+import java.util.ArrayList;
+import java.util.EnumSet;
+import java.util.List;
+import java.util.Set;
+
+import org.jivesoftware.smack.XMPPConnection;
+import org.jivesoftware.smack.packet.AbstractIqBuilder;
+import org.jivesoftware.smack.packet.IQ;
+import org.jivesoftware.smack.packet.IqBuilder;
+import org.jivesoftware.smack.packet.IqData;
+import org.jivesoftware.smack.util.StringUtils;
+
+import org.jivesoftware.smackx.commands.AdHocCommandNote;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Action;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Status;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+public class AdHocCommandDataBuilder extends IqBuilder<AdHocCommandDataBuilder, AdHocCommandData> implements AdHocCommandDataView {
+
+    private final String node;
+
+    private String name;
+
+    private String sessionId;
+
+    private final List<AdHocCommandNote> notes = new ArrayList<>();
+
+    private DataForm form;
+
+    /* Action request to be executed */
+    private Action action;
+
+    /* Current execution status */
+    private Status status;
+
+    private final Set<AllowedAction> actions = EnumSet.noneOf(AllowedAction.class);
+
+    private AllowedAction executeAction;
+
+    AdHocCommandDataBuilder(String node, IqData iqCommon) {
+        super(iqCommon);
+        this.node = StringUtils.requireNotNullNorEmpty(node, "Ad-Hoc Command node must be set");
+    }
+
+    AdHocCommandDataBuilder(String node, String stanzaId) {
+        super(stanzaId);
+        this.node = StringUtils.requireNotNullNorEmpty(node, "Ad-Hoc Command node must be set");
+    }
+
+    AdHocCommandDataBuilder(String node, XMPPConnection connection) {
+        super(connection);
+        this.node = StringUtils.requireNotNullNorEmpty(node, "Ad-Hoc Command node must be set");
+    }
+
+    @Override
+    public String getNode() {
+        return node;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    public AdHocCommandDataBuilder setName(String name) {
+        this.name = name;
+        return getThis();
+    }
+
+    @Override
+    public String getSessionId() {
+        return sessionId;
+    }
+
+    public AdHocCommandDataBuilder setSessionId(String sessionId) {
+        this.sessionId = sessionId;
+        return getThis();
+    }
+
+    @Override
+    public List<AdHocCommandNote> getNotes() {
+        return notes;
+    }
+
+    public AdHocCommandDataBuilder addNote(AdHocCommandNote note) {
+        notes.add(note);
+        return getThis();
+    }
+
+    @Override
+    public DataForm getForm() {
+        return form;
+    }
+
+    public AdHocCommandDataBuilder setForm(DataForm form) {
+        this.form = form;
+        return getThis();
+    }
+
+    @Override
+    public Action getAction() {
+        return action;
+    }
+
+    public AdHocCommandDataBuilder setAction(AdHocCommandData.Action action) {
+        this.action = action;
+        return getThis();
+    }
+    @Override
+
+    public AdHocCommandData.Status getStatus() {
+        return status;
+    }
+
+    public AdHocCommandDataBuilder setStatus(AdHocCommandData.Status status) {
+        this.status = status;
+        return getThis();
+    }
+
+    public AdHocCommandDataBuilder setStatusCompleted() {
+        return setStatus(AdHocCommandData.Status.completed);
+    }
+
+    public enum PreviousStage {
+        exists,
+        none,
+    }
+
+    public enum NextStage {
+        isFinal,
+        nonFinal,
+    }
+
+    @SuppressWarnings("fallthrough")
+    public AdHocCommandDataBuilder setStatusExecuting(PreviousStage previousStage, NextStage nextStage) {
+        setStatus(AdHocCommandData.Status.executing);
+
+        switch (previousStage) {
+        case exists:
+            addAction(AllowedAction.prev);
+            break;
+        case none:
+            break;
+        }
+
+        setExecuteAction(AllowedAction.next);
+
+        switch (nextStage) {
+        case isFinal:
+            addAction(AllowedAction.complete);
+            // Override execute action of 'next'.
+            setExecuteAction(AllowedAction.complete);
+            // Deliberate fallthrough, we want 'next' to be added.
+        case nonFinal:
+            addAction(AllowedAction.next);
+            break;
+        }
+
+        return getThis();
+    }
+
+    @Override
+    public Set<AllowedAction> getActions() {
+        return actions;
+    }
+
+    public AdHocCommandDataBuilder addAction(AllowedAction action) {
+        actions.add(action);
+        return getThis();
+    }
+
+    @Override
+    public AllowedAction getExecuteAction() {
+        return executeAction;
+    }
+
+    public AdHocCommandDataBuilder setExecuteAction(AllowedAction action) {
+        this.executeAction = action;
+        return getThis();
+    }
+
+    @Override
+    public AdHocCommandData build() {
+        return new AdHocCommandData(this);
+    }
+
+    @Override
+    public AdHocCommandDataBuilder getThis() {
+        return this;
+    }
+
+    public static AdHocCommandDataBuilder buildResponseFor(AdHocCommandData request) {
+        return buildResponseFor(request, IQ.ResponseType.result);
+    }
+
+    public static AdHocCommandDataBuilder buildResponseFor(AdHocCommandData request, IQ.ResponseType responseType) {
+        AdHocCommandDataBuilder builder = new AdHocCommandDataBuilder(request.getNode(), AbstractIqBuilder.createResponse(request, responseType));
+        return builder;
+    }
+
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/packet/AdHocCommandDataView.java

@@ -0,0 +1,87 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands.packet;
+
+import java.util.List;
+import java.util.Set;
+
+import org.jivesoftware.smack.packet.IqView;
+
+import org.jivesoftware.smackx.commands.AdHocCommandNote;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Action;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Status;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+public interface AdHocCommandDataView extends IqView {
+
+    /**
+     * Returns the identifier of the command.
+     *
+     * @return the node.
+     */
+    String getNode();
+
+    /**
+     * Returns the human name of the command.
+     *
+     * @return the name of the command.
+     */
+    String getName();
+
+    String getSessionId();
+
+    /**
+     * Returns the list of notes that the command has.
+     *
+     * @return the notes.
+     */
+    List<AdHocCommandNote> getNotes();
+
+    /**
+     * Returns the form of the command.
+     *
+     * @return the data form associated with the command.
+     */
+    DataForm getForm();
+
+    /**
+     * Returns the action to execute. The action is set only on a request.
+     *
+     * @return the action to execute.
+     */
+    Action getAction();
+
+    /**
+     * Returns the status of the execution.
+     *
+     * @return the status.
+     */
+    Status getStatus();
+
+    Set<AllowedAction> getActions();
+
+    AllowedAction getExecuteAction();
+
+    default boolean isCompleted() {
+        return getStatus() == Status.completed;
+    }
+
+    default boolean isExecuting() {
+        return getStatus() == Status.executing;
+    }
+}

smack-extensions/src/main/java/org/jivesoftware/smackx/commands/provider/AdHocCommandDataProvider.java

@@ -29,10 +29,13 @@ import org.jivesoftware.smack.util.PacketParserUtils;
 import org.jivesoftware.smack.xml.XmlPullParser;
 import org.jivesoftware.smack.xml.XmlPullParserException;
 
-import org.jivesoftware.smackx.commands.AdHocCommand;
-import org.jivesoftware.smackx.commands.AdHocCommand.Action;
 import org.jivesoftware.smackx.commands.AdHocCommandNote;
+import org.jivesoftware.smackx.commands.SpecificErrorCondition;
 import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.Action;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData.AllowedAction;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
 import org.jivesoftware.smackx.xdata.provider.DataFormProvider;
 
 /**
@@ -44,64 +47,69 @@ public class AdHocCommandDataProvider extends IqProvider<AdHocCommandData> {
 
     @Override
     public AdHocCommandData parse(XmlPullParser parser, int initialDepth, IqData iqData, XmlEnvironment xmlEnvironment) throws XmlPullParserException, IOException, SmackParsingException {
-        boolean done = false;
+        String commandNode = parser.getAttributeValue("node");
-        AdHocCommandData adHocCommandData = new AdHocCommandData();
+        AdHocCommandDataBuilder builder = AdHocCommandData.builder(commandNode, iqData);
         DataFormProvider dataFormProvider = new DataFormProvider();
 
-        XmlPullParser.Event eventType;
+        String sessionId = parser.getAttributeValue("sessionid");
-        String elementName;
+        builder.setSessionId(sessionId);
-        String namespace;
-        adHocCommandData.setSessionID(parser.getAttributeValue("", "sessionid"));
-        adHocCommandData.setNode(parser.getAttributeValue("", "node"));
 
         // Status
         String status = parser.getAttributeValue("", "status");
-        if (AdHocCommand.Status.executing.toString().equalsIgnoreCase(status)) {
+        if (AdHocCommandData.Status.executing.toString().equalsIgnoreCase(status)) {
-            adHocCommandData.setStatus(AdHocCommand.Status.executing);
+            builder.setStatus(AdHocCommandData.Status.executing);
         }
-        else if (AdHocCommand.Status.completed.toString().equalsIgnoreCase(status)) {
+        else if (AdHocCommandData.Status.completed.toString().equalsIgnoreCase(status)) {
-            adHocCommandData.setStatus(AdHocCommand.Status.completed);
+            builder.setStatus(AdHocCommandData.Status.completed);
         }
-        else if (AdHocCommand.Status.canceled.toString().equalsIgnoreCase(status)) {
+        else if (AdHocCommandData.Status.canceled.toString().equalsIgnoreCase(status)) {
-            adHocCommandData.setStatus(AdHocCommand.Status.canceled);
+            builder.setStatus(AdHocCommandData.Status.canceled);
         }
 
         // Action
         String action = parser.getAttributeValue("", "action");
         if (action != null) {
-            Action realAction = AdHocCommand.Action.valueOf(action);
+            Action realAction = Action.valueOf(action);
-            if (realAction == null || realAction.equals(Action.unknown)) {
+            if (realAction == null) {
-                adHocCommandData.setAction(Action.unknown);
+                throw new SmackParsingException("Invalid value for action attribute: " + action);
             }
-            else {
+
-                adHocCommandData.setAction(realAction);
+            builder.setAction(realAction);
         }
-        }
+
-        while (!done) {
+        // TODO: Improve parsing below. Currently, the next actions like <prev/> are not checked for the correct position.
-            eventType = parser.next();
+        outerloop:
-            namespace = parser.getNamespace();
+        while (true) {
-            if (eventType == XmlPullParser.Event.START_ELEMENT) {
+            String elementName;
+            XmlPullParser.Event event = parser.next();
+            String namespace = parser.getNamespace();
+            switch (event) {
+            case START_ELEMENT:
                 elementName = parser.getName();
-                if (parser.getName().equals("actions")) {
+                switch (elementName) {
-                    String execute = parser.getAttributeValue("", "execute");
+                case "actions":
+                    String execute = parser.getAttributeValue("execute");
                     if (execute != null) {
-                        adHocCommandData.setExecuteAction(AdHocCommand.Action.valueOf(execute));
+                        builder.setExecuteAction(AllowedAction.valueOf(execute));
                     }
+                    break;
+                case "next":
+                    builder.addAction(AllowedAction.next);
+                    break;
+                case "complete":
+                    builder.addAction(AllowedAction.complete);
+                    break;
+                case "prev":
+                    builder.addAction(AllowedAction.prev);
+                    break;
+                case "x":
+                    if (namespace.equals("jabber:x:data")) {
+                        DataForm form = dataFormProvider.parse(parser);
+                        builder.setForm(form);
                     }
-                else if (parser.getName().equals("next")) {
+                    break;
-                    adHocCommandData.addAction(AdHocCommand.Action.next);
+                case "note":
-                }
+                    String typeString = parser.getAttributeValue("type");
-                else if (parser.getName().equals("complete")) {
-                    adHocCommandData.addAction(AdHocCommand.Action.complete);
-                }
-                else if (parser.getName().equals("prev")) {
-                    adHocCommandData.addAction(AdHocCommand.Action.prev);
-                }
-                else if (elementName.equals("x") && namespace.equals("jabber:x:data")) {
-                    adHocCommandData.setForm(dataFormProvider.parse(parser));
-                }
-                else if (parser.getName().equals("note")) {
-                    String typeString = parser.getAttributeValue("", "type");
                     AdHocCommandNote.Type type;
                     if (typeString != null) {
                         type = AdHocCommandNote.Type.valueOf(typeString);
@@ -110,61 +118,67 @@ public class AdHocCommandDataProvider extends IqProvider<AdHocCommandData> {
                         type = AdHocCommandNote.Type.info;
                     }
                     String value = parser.nextText();
-                    adHocCommandData.addNote(new AdHocCommandNote(type, value));
+                    builder.addNote(new AdHocCommandNote(type, value));
-                }
+                    break;
-                else if (parser.getName().equals("error")) {
+                case "error":
                     StanzaError error = PacketParserUtils.parseError(parser);
-                    adHocCommandData.setError(error);
+                    builder.setError(error);
+                    break;
                 }
-            }
+                break;
-            else if (eventType == XmlPullParser.Event.END_ELEMENT) {
+            case END_ELEMENT:
                 if (parser.getName().equals("command")) {
-                    done = true;
+                    break outerloop;
+                }
+                break;
+            default:
+                // Catch all for incomplete switch (MissingCasesInEnumSwitch) statement.
+                break;
             }
         }
-        }
+
-        return adHocCommandData;
+        return builder.build();
     }
 
     public static class BadActionError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.badAction);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.badAction);
         }
     }
 
     public static class MalformedActionError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.malformedAction);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.malformedAction);
         }
     }
 
     public static class BadLocaleError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.badLocale);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.badLocale);
         }
     }
 
     public static class BadPayloadError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.badPayload);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.badPayload);
         }
     }
 
     public static class BadSessionIDError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.badSessionid);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.badSessionid);
         }
     }
 
     public static class SessionExpiredError extends ExtensionElementProvider<AdHocCommandData.SpecificError> {
         @Override
         public AdHocCommandData.SpecificError parse(XmlPullParser parser, int initialDepth, XmlEnvironment xmlEnvironment)  {
-            return new AdHocCommandData.SpecificError(AdHocCommand.SpecificErrorCondition.sessionExpired);
+            return new AdHocCommandData.SpecificError(SpecificErrorCondition.sessionExpired);
         }
     }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/form/FillableForm.java

@@ -270,4 +270,8 @@ public class FillableForm extends FilledForm {
         return builder.build();
     }
 
+    public SubmitForm getSubmitForm() {
+        DataForm form = getDataFormToSubmit();
+        return new SubmitForm(form);
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/form/SubmitForm.java

@@ -0,0 +1,31 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.xdata.form;
+
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+public class SubmitForm extends FilledForm {
+
+    public SubmitForm(DataForm dataForm) {
+        super(dataForm);
+
+        if (dataForm.getType() != DataForm.Type.submit) {
+            throw new IllegalArgumentException();
+        }
+    }
+
+}

smack-extensions/src/test/java/org/jivesoftware/smackx/commands/provider/CommandsProviderTest.java

@@ -23,7 +23,6 @@ import org.jivesoftware.smack.packet.Stanza;
 import org.jivesoftware.smack.packet.StanzaError;
 import org.jivesoftware.smack.util.PacketParserUtils;
 
-import org.jivesoftware.smackx.commands.AdHocCommand;
 import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
 
 import org.junit.jupiter.api.Test;
@@ -41,7 +40,7 @@ public class CommandsProviderTest {
         final AdHocCommandData adHocIq = (AdHocCommandData) requestStanza;
 
         assertEquals(IQ.Type.error, adHocIq.getType());
-        assertEquals(AdHocCommand.Action.execute, adHocIq.getAction());
+        assertEquals(AdHocCommandData.Action.execute, adHocIq.getAction());
 
         StanzaError error = adHocIq.getError();
         assertEquals(StanzaError.Type.CANCEL, error.getType());

smack-extensions/src/test/java/org/jivesoftware/smackx/xdata/form/FillableFormTest.java

@@ -0,0 +1,44 @@
+/**
+ *
+ * Copyright 2024 Florian Schmaus.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.xdata.form;
+
+import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.jivesoftware.smackx.xdata.FormField;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+import org.junit.jupiter.api.Test;
+
+public class FillableFormTest {
+
+    @Test
+    public void testThrowOnIncompleteyFilled() {
+        FormField fieldA = FormField.textSingleBuilder("a").setRequired().build();
+        FormField fieldB = FormField.textSingleBuilder("b").setRequired().build();
+        DataForm form = DataForm.builder(DataForm.Type.form)
+                        .addField(fieldA)
+                        .addField(fieldB)
+                        .build();
+
+        FillableForm fillableForm = new FillableForm(form);
+        fillableForm.setAnswer("a", 42);
+
+        IllegalStateException ise = assertThrows(IllegalStateException.class, () -> fillableForm.getSubmitForm());
+        assertTrue(ise.getMessage().startsWith("Not all required fields filled. "));
+    }
+}

smack-integration-test/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandIntegrationTest.java

@@ -0,0 +1,353 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.jivesoftware.smackx.commands;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import org.jivesoftware.smack.SmackException.NoResponseException;
+import org.jivesoftware.smack.SmackException.NotConnectedException;
+import org.jivesoftware.smack.XMPPException.XMPPErrorException;
+import org.jivesoftware.smack.packet.StanzaError;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandData;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder.NextStage;
+import org.jivesoftware.smackx.commands.packet.AdHocCommandDataBuilder.PreviousStage;
+import org.jivesoftware.smackx.xdata.FormField;
+import org.jivesoftware.smackx.xdata.form.FillableForm;
+import org.jivesoftware.smackx.xdata.form.SubmitForm;
+import org.jivesoftware.smackx.xdata.packet.DataForm;
+
+import org.igniterealtime.smack.inttest.AbstractSmackIntegrationTest;
+import org.igniterealtime.smack.inttest.SmackIntegrationTestEnvironment;
+import org.igniterealtime.smack.inttest.annotations.SmackIntegrationTest;
+
+public class AdHocCommandIntegrationTest extends AbstractSmackIntegrationTest {
+
+    public AdHocCommandIntegrationTest(SmackIntegrationTestEnvironment environment) {
+        super(environment);
+    }
+
+    @SmackIntegrationTest
+    public void singleStageAdHocCommandTest() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        AdHocCommandManager manOne = AdHocCommandManager.getInstance(conOne);
+        AdHocCommandManager manTwo = AdHocCommandManager.getInstance(conTwo);
+
+        String commandNode = "test-list";
+        String commandName = "Return a list for testing purposes";
+        AdHocCommandHandlerFactory factory = (String node, String name, String sessionId) -> {
+            return new AdHocCommandHandler.SingleStage(node, name, sessionId) {
+                @Override
+                public AdHocCommandData executeSingleStage(AdHocCommandDataBuilder response) {
+                    FormField field = FormField.textPrivateBuilder("my-field").build();
+                    DataForm form = DataForm.builder(DataForm.Type.result).addField(field).build();
+
+                    response.setForm(form);
+
+                    return response.build();
+                }
+            };
+        };
+        manOne.registerCommand(commandNode, commandName, factory);
+        try {
+            AdHocCommand command = manTwo.getRemoteCommand(conOne.getUser(), commandNode);
+
+            AdHocCommandResult result = command.execute();
+            AdHocCommandData response = result.getResponse();
+            DataForm form = response.getForm();
+            FormField field = form.getField("my-field");
+            assertNotNull(field);
+        } finally {
+            manOne.unregisterCommand(commandNode);
+        }
+    }
+
+    private static class MyMultiStageAdHocCommandServer extends AdHocCommandHandler {
+
+        private Integer a;
+        private Integer b;
+
+        private static DataForm createDataForm(String variableName) {
+            FormField field = FormField.textSingleBuilder(variableName).setRequired().build();
+            return DataForm.builder(DataForm.Type.form)
+               .setTitle("Variable " + variableName)
+               .setInstructions("Please provide an integer variable " + variableName)
+               .addField(field)
+               .build();
+        }
+
+        private static DataForm createDataFormOp() {
+            FormField field = FormField.listSingleBuilder("op")
+                            .setLabel("Arthimetic Operation")
+                            .setRequired()
+                            .addOption("+")
+                            .addOption("-")
+                            .build();
+            return DataForm.builder(DataForm.Type.form)
+               .setTitle("Operation")
+               .setInstructions("Please select the arithmetic operation to be performed with a and b")
+               .addField(field)
+               .build();
+        }
+        private static final DataForm dataFormAskingForA = createDataForm("a");
+        private static final DataForm dataFormAskingForB = createDataForm("b");
+        private static final DataForm dataFormAskingForOp = createDataFormOp();
+
+        MyMultiStageAdHocCommandServer(String node, String name, String sessionId) {
+            super(node, name, sessionId);
+        }
+
+        @Override
+        protected AdHocCommandData execute(AdHocCommandDataBuilder response) throws XMPPErrorException {
+            return response.setForm(dataFormAskingForA).setStatusExecuting(PreviousStage.none,
+                            NextStage.nonFinal).build();
+        }
+
+        // TODO: Add API for every case where we return null or throw below.
+        private static Integer extractIntegerField(SubmitForm form, String fieldName) throws XMPPErrorException {
+            FormField field = form.getField(fieldName);
+            if (field == null)
+                throw newBadRequestException("Submitted form does not contain a field of name " + fieldName);
+
+            String fieldValue = field.getFirstValue();
+            if (fieldValue == null)
+                throw newBadRequestException("Submitted form contains field of name " + fieldName + " without value");
+
+            try {
+                return Integer.parseInt(fieldValue);
+            } catch (NumberFormatException e) {
+                throw newBadRequestException("Submitted form contains field of name " + fieldName + " with value " + fieldValue + " that is not an integer");
+            }
+        }
+
+        @Override
+        protected AdHocCommandData next(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                        throws XMPPErrorException {
+            DataForm form;
+            switch (getCurrentStage()) {
+            case 2:
+                a = extractIntegerField(submittedForm, "a");
+                form = dataFormAskingForB;
+                response.setStatusExecuting(PreviousStage.exists, NextStage.nonFinal);
+                break;
+            case 3:
+                b = extractIntegerField(submittedForm, "b");
+                form = dataFormAskingForOp;
+                response.setStatusExecuting(PreviousStage.exists, NextStage.isFinal);
+                break;
+            case 4:
+                // Ad-Hoc Commands particularity: Can get to 'complete' via 'next'.
+                return complete(response, submittedForm);
+            default:
+                throw new IllegalStateException();
+            }
+
+            return response.setForm(form).build();
+        }
+
+        @Override
+        protected AdHocCommandData complete(AdHocCommandDataBuilder response, SubmitForm submittedForm)
+                        throws XMPPErrorException {
+            if (getCurrentStage() != 4) {
+                throw new IllegalStateException();
+            }
+
+            if (a == null || b == null) {
+                throw new IllegalStateException();
+            }
+
+            String op = submittedForm.getField("op").getFirstValue();
+
+            int result;
+            switch (op) {
+            case "+":
+                result = a + b;
+                break;
+            case "-":
+                result = a - b;
+                break;
+            default:
+                throw newBadRequestException("Submitted operation " + op + " is neither + nor -");
+            }
+
+            response.setStatusCompleted();
+
+            FormField field = FormField.textSingleBuilder("result").setValue(result).build();
+            DataForm form = DataForm.builder(DataForm.Type.result).setTitle("Result").addField(field).build();
+
+            return response.setForm(form).build();
+        }
+
+        @Override
+        protected AdHocCommandData prev(AdHocCommandDataBuilder response) throws XMPPErrorException {
+            switch (getCurrentStage()) {
+            case 1:
+                return execute(response);
+            case 2:
+                return response.setForm(dataFormAskingForA)
+                                .setStatusExecuting(PreviousStage.exists, NextStage.nonFinal)
+                                .build();
+            case 3:
+                return response.setForm(dataFormAskingForB)
+                                .setStatusExecuting(PreviousStage.exists, NextStage.isFinal)
+                                .build();
+            default:
+                throw new IllegalStateException();
+            }
+        }
+
+        @Override
+        public void cancel() {
+        }
+
+    }
+
+    @SmackIntegrationTest
+    public void multiStageAdHocCommandTest() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        AdHocCommandManager manOne = AdHocCommandManager.getInstance(conOne);
+        AdHocCommandManager manTwo = AdHocCommandManager.getInstance(conTwo);
+
+        String commandNode = "my-multi-stage-command";
+        String commandName = "An example multi-sage ad-hoc command";
+        AdHocCommandHandlerFactory factory = (String node, String name, String sessionId) -> {
+            return new MyMultiStageAdHocCommandServer(node, name, sessionId);
+        };
+        manOne.registerCommand(commandNode, commandName, factory);
+
+        try {
+            AdHocCommand command = manTwo.getRemoteCommand(conOne.getUser(), commandNode);
+
+            AdHocCommandResult.StatusExecuting result = command.execute().asExecutingOrThrow();
+
+            FillableForm form = result.getFillableForm();
+            form.setAnswer("a", 42);
+
+            SubmitForm submitForm = form.getSubmitForm();
+
+
+            result = command.next(submitForm).asExecutingOrThrow();
+
+            form = result.getFillableForm();
+            form.setAnswer("b", 23);
+
+            submitForm = form.getSubmitForm();
+
+
+            result = command.next(submitForm).asExecutingOrThrow();
+
+            form = result.getFillableForm();
+            form.setAnswer("op", "+");
+
+            submitForm = form.getSubmitForm();
+
+            AdHocCommandResult.StatusCompleted completed = command.complete(submitForm).asCompletedOrThrow();
+
+            String operationResult = completed.getResponse().getForm().getField("result").getFirstValue();
+            assertEquals("65", operationResult);
+        } finally {
+            manTwo.unregisterCommand(commandNode);
+        }
+    }
+
+    @SmackIntegrationTest
+    public void multiStageWithPrevAdHocCommandTest() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        AdHocCommandManager manOne = AdHocCommandManager.getInstance(conOne);
+        AdHocCommandManager manTwo = AdHocCommandManager.getInstance(conTwo);
+
+        String commandNode = "my-multi-stage-with-prev-command";
+        String commandName = "An example multi-sage ad-hoc command";
+        AdHocCommandHandlerFactory factory = (String node, String name, String sessionId) -> {
+            return new MyMultiStageAdHocCommandServer(node, name, sessionId);
+        };
+        manOne.registerCommand(commandNode, commandName, factory);
+
+        try {
+            AdHocCommand command = manTwo.getRemoteCommand(conOne.getUser(), commandNode);
+
+            AdHocCommandResult.StatusExecuting result = command.execute().asExecutingOrThrow();
+
+            FillableForm form = result.getFillableForm();
+            form.setAnswer("a", 42);
+
+            SubmitForm submitForm = form.getSubmitForm();
+
+            command.next(submitForm).asExecutingOrThrow();
+
+
+            // Ups, I wanted a different value for 'a', lets execute 'prev' to get back to the previous stage.
+            result = command.prev().asExecutingOrThrow();
+
+            form = result.getFillableForm();
+            form.setAnswer("a", 77);
+
+            submitForm = form.getSubmitForm();
+
+
+            result = command.next(submitForm).asExecutingOrThrow();
+
+            form = result.getFillableForm();
+            form.setAnswer("b", 23);
+
+            submitForm = form.getSubmitForm();
+
+
+            result = command.next(submitForm).asExecutingOrThrow();
+
+            form = result.getFillableForm();
+            form.setAnswer("op", "+");
+
+            submitForm = form.getSubmitForm();
+
+            AdHocCommandResult.StatusCompleted completed = command.complete(submitForm).asCompletedOrThrow();
+
+            String operationResult = completed.getResponse().getForm().getField("result").getFirstValue();
+            assertEquals("100", operationResult);
+        } finally {
+            manTwo.unregisterCommand(commandNode);
+        }
+    }
+
+    @SmackIntegrationTest
+    public void multiStageInvalidArgAdHocCommandTest() throws NoResponseException, XMPPErrorException, NotConnectedException, InterruptedException {
+        AdHocCommandManager manOne = AdHocCommandManager.getInstance(conOne);
+        AdHocCommandManager manTwo = AdHocCommandManager.getInstance(conTwo);
+
+        String commandNode = "my-multi-stage-invalid-arg-command";
+        String commandName = "An example multi-sage ad-hoc command";
+        AdHocCommandHandlerFactory factory = (String node, String name, String sessionId) -> {
+            return new MyMultiStageAdHocCommandServer(node, name, sessionId);
+        };
+        manOne.registerCommand(commandNode, commandName, factory);
+
+        try {
+            AdHocCommand command = manTwo.getRemoteCommand(conOne.getUser(), commandNode);
+
+            AdHocCommandResult.StatusExecuting result = command.execute().asExecutingOrThrow();
+
+            FillableForm form = result.getFillableForm();
+            form.setAnswer("a", "forty-two");
+
+            SubmitForm submitForm = form.getSubmitForm();
+
+            XMPPErrorException exception = assertThrows(XMPPErrorException.class, () -> command.next(submitForm));
+            assertEquals(exception.getStanzaError().getCondition(), StanzaError.Condition.bad_request);
+        } finally {
+            manTwo.unregisterCommand(commandNode);
+        }
+    }
+}

smack-integration-test/src/main/java/org/jivesoftware/smackx/commands/package-info.java

@@ -0,0 +1,22 @@
+/**
+ *
+ * Copyright 2023 Florian Schmaus
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+/**
+ * Smacks implementation of XEP-0050: Ad-Hoc Commands.
+ */
+package org.jivesoftware.smackx.commands;