Improve SHIM API

- HeadersExtension.getHeaders() now returns a List instead of a
  Collection
- Use XmlStringBuilder in Header and HeadersExtension toXML()
- Add HeadersProviderTest
- Use Smack formatting

Also remove duplicate parsing code regarding SHIM from HOXT
implementation.

smack-core/src/main/java/org/jivesoftware/smack/util/XmlStringBuilder.java

@@ -16,6 +16,8 @@
  */
 package org.jivesoftware.smack.util;
 
+import java.util.Collection;
+
 import org.jivesoftware.smack.packet.Element;
 import org.jivesoftware.smack.packet.NamedElement;
 import org.jivesoftware.smack.packet.PacketExtension;
@@ -272,6 +274,13 @@ public class XmlStringBuilder implements Appendable, CharSequence {
         return this;
     }
 
+    public XmlStringBuilder append(Collection<? extends Element> elements) {
+        for (Element element : elements) {
+            append(element.toXML());
+        }
+        return this;
+    }
+
     public XmlStringBuilder emptyElement(Enum<?> element) {
         return emptyElement(element.name());
     }

smack-experimental/src/main/java/org/jivesoftware/smackx/hoxt/provider/AbstractHttpOverXmppProvider.java

@@ -21,15 +21,12 @@ import org.jivesoftware.smack.packet.NamedElement;
 import org.jivesoftware.smack.provider.IQProvider;
 import org.jivesoftware.smack.util.StringUtils;
 import org.jivesoftware.smackx.hoxt.packet.AbstractHttpOverXmpp;
-import org.jivesoftware.smackx.shim.packet.Header;
 import org.jivesoftware.smackx.shim.packet.HeadersExtension;
-import org.jivesoftware.smackx.shim.provider.HeaderProvider;
+import org.jivesoftware.smackx.shim.provider.HeadersProvider;
 import org.xmlpull.v1.XmlPullParser;
 import org.xmlpull.v1.XmlPullParserException;
 
 import java.io.IOException;
-import java.util.HashSet;
-import java.util.Set;
 
 /**
  * Abstract parent for Req and Resp packet providers.
@@ -39,8 +36,6 @@ import java.util.Set;
  */
 public abstract class AbstractHttpOverXmppProvider<H extends AbstractHttpOverXmpp> extends IQProvider<H> {
 
-    private static final String ELEMENT_HEADERS = "headers";
-    private static final String ELEMENT_HEADER = "header";
     private static final String ELEMENT_DATA = "data";
     private static final String ELEMENT_TEXT = "text";
     private static final String ELEMENT_BASE_64 = "base64";
@@ -71,8 +66,8 @@ public abstract class AbstractHttpOverXmppProvider<H extends AbstractHttpOverXmp
             int eventType = parser.next();
 
             if (eventType == XmlPullParser.START_TAG) {
-                if (parser.getName().equals(ELEMENT_HEADERS)) {
+                if (parser.getName().equals(HeadersExtension.ELEMENT)) {
-                    HeadersExtension headersExtension = parseHeaders(parser);
+                    HeadersExtension headersExtension = HeadersProvider.INSTANCE.parse(parser);
                     body.setHeaders(headersExtension);
                 } else if (parser.getName().endsWith(ELEMENT_DATA)) {
                     AbstractHttpOverXmpp.Data data = parseData(parser);
@@ -88,28 +83,6 @@ public abstract class AbstractHttpOverXmppProvider<H extends AbstractHttpOverXmp
         }
     }
 
-    private HeadersExtension parseHeaders(XmlPullParser parser) throws XmlPullParserException, IOException, SmackException {
-        HeaderProvider provider = new HeaderProvider();
-        Set<Header> set = new HashSet<Header>();
-        boolean done = false;
-
-        while (!done) {
-            int eventType = parser.next();
-
-            if (eventType == XmlPullParser.START_TAG) {
-                if (parser.getName().equals(ELEMENT_HEADER)) {
-                    Header header = provider.parse(parser);
-                    set.add(header);
-                }
-            } else if (eventType == XmlPullParser.END_TAG) {
-                if (parser.getName().equals(ELEMENT_HEADERS)) {
-                    done = true;
-                }
-            }
-        }
-        return new HeadersExtension(set);
-    }
-
     private AbstractHttpOverXmpp.Data parseData(XmlPullParser parser) throws XmlPullParserException, IOException {
         NamedElement child = null;
         boolean done = false;

smack-extensions/src/main/java/org/jivesoftware/smackx/shim/packet/Header.java

@@ -16,47 +16,50 @@
  */
 package org.jivesoftware.smackx.shim.packet;
 
+import org.jivesoftware.smack.packet.NamedElement;
 import org.jivesoftware.smack.packet.PacketExtension;
+import org.jivesoftware.smack.util.XmlStringBuilder;
 
 /**
  * Represents a <b>Header</b> entry as specified by the <a href="http://xmpp.org/extensions/xep-031.html">Stanza Headers and Internet Metadata (SHIM)</a>
 
  * @author Robin Collier
  */
-public class Header implements PacketExtension
+public class Header implements PacketExtension {
-{
+    public static final String ELEMENT = "header";
-	private String name;
-	private String value;
 
-	public Header(String name, String value)
+    private final String name;
-	{
+    private final String value;
+
+    public Header(String name, String value) {
         this.name = name;
         this.value = value;
     }
 
-	public String getName()
+    public String getName() {
-	{
         return name;
     }
 
-	public String getValue()
+    public String getValue() {
-	{
         return value;
     }
 
-	public String getElementName()
+    public String getElementName() {
-	{
+        return ELEMENT;
-		return "header";
     }
 
-	public String getNamespace()
+    public String getNamespace() {
-	{
         return HeadersExtension.NAMESPACE;
     }
 
-	public String toXML()
+    @Override
-	{
+    public XmlStringBuilder toXML() {
-		return "<header name='" + name + "'>" + value + "</header>";
+        // Upcast to NamedElement since we don't want a xmlns attribute
+        XmlStringBuilder xml = new XmlStringBuilder((NamedElement) this);
+        xml.attribute("name", name);
+        xml.rightAngleBracket();
+        xml.escape(value);
+        xml.closeElement(this);
+        return xml;
     }
-
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/shim/packet/HeadersExtension.java

@@ -16,10 +16,12 @@
  */
 package org.jivesoftware.smackx.shim.packet;
 
-import java.util.Collection;
 import java.util.Collections;
+import java.util.List;
 
+import org.jivesoftware.smack.packet.Packet;
 import org.jivesoftware.smack.packet.PacketExtension;
+import org.jivesoftware.smack.util.XmlStringBuilder;
 
 /**
  * Extension representing a list of headers as specified in <a href="http://xmpp.org/extensions/xep-0131">Stanza Headers and Internet Metadata (SHIM)</a>
@@ -28,44 +30,48 @@ import org.jivesoftware.smack.packet.PacketExtension;
  * 
  * @author Robin Collier
  */
-public class HeadersExtension implements PacketExtension
+public class HeadersExtension implements PacketExtension {
-{
+    public static final String ELEMENT = "headers";
     public static final String NAMESPACE = "http://jabber.org/protocol/shim";
 
-	private Collection<Header> headers = Collections.emptyList();
+    private final List<Header> headers;
 
-	public HeadersExtension(Collection<Header> headerList)
+    public HeadersExtension(List<Header> headerList) {
-	{
+        if (headerList != null) {
-		if (headerList != null)
+            headers = Collections.unmodifiableList(headerList);
-			headers = headerList;
+        } else {
+            headers = Collections.emptyList();
+        }
     }
 
-	public Collection<Header> getHeaders()
+    public List<Header> getHeaders() {
-	{
         return headers;
     }
 
-	public String getElementName()
+    public String getElementName() {
-	{
+        return ELEMENT;
-		return "headers";
     }
 
-	public String getNamespace()
+    public String getNamespace() {
-	{
         return NAMESPACE;
     }
 
-	public String toXML()
+    @Override
-	{
+    public XmlStringBuilder toXML() {
-		StringBuilder builder = new StringBuilder("<" + getElementName() + " xmlns='" + getNamespace() + "'>");
+        XmlStringBuilder xml = new XmlStringBuilder(this);
-		
+        xml.rightAngleBracket();
-		for (Header header : headers)
+        xml.append(headers);
-		{
+        xml.closeElement(this);
-			builder.append(header.toXML());
+        return xml;
-		}
-		builder.append("</" + getElementName() + '>');
-
-		return builder.toString();
     }
 
+    /**
+     * Return the SHIM headers extension of this stanza or null if there is none.
+     *
+     * @param packet
+     * @return the headers extension or null.
+     */
+    public static HeadersExtension from(Packet packet) {
+        return packet.getExtension(ELEMENT, NAMESPACE);
+    }
 }

smack-extensions/src/main/java/org/jivesoftware/smackx/shim/provider/HeaderProvider.java

@@ -28,21 +28,21 @@ import org.xmlpull.v1.XmlPullParserException;
  * 
  * @author Robin Collier
  */
-public class HeaderProvider extends PacketExtensionProvider<Header>
+public class HeaderProvider extends PacketExtensionProvider<Header> {
-{
     @Override
-    public Header parse(XmlPullParser parser, int initialDepth)
+    public Header parse(XmlPullParser parser, int initialDepth) throws XmlPullParserException, IOException {
-                    throws XmlPullParserException, IOException {
         String name = parser.getAttributeValue(null, "name");
         String value = null;
 
         parser.next();
 
-		if (parser.getEventType() == XmlPullParser.TEXT)
+        if (parser.getEventType() == XmlPullParser.TEXT) {
             value = parser.getText();
+        }
 
-		while(parser.getEventType() != XmlPullParser.END_TAG)
+        while (parser.getEventType() != XmlPullParser.END_TAG) {
             parser.next();
+        }
 
         return new Header(name, value);
     }

smack-extensions/src/main/java/org/jivesoftware/smackx/shim/provider/HeadersProvider.java

@@ -16,7 +16,6 @@
  */
 package org.jivesoftware.smackx.shim.provider;
 
-import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 
@@ -30,13 +29,14 @@ import org.jivesoftware.smackx.shim.packet.HeadersExtension;
  * 
  * @author Robin Collier
  */
-public class HeadersProvider extends EmbeddedExtensionProvider<HeadersExtension>
+public class HeadersProvider extends EmbeddedExtensionProvider<HeadersExtension> {
-{
+    public static final HeadersProvider INSTANCE = new HeadersProvider();
+
     @SuppressWarnings("unchecked")
     @Override
-	protected HeadersExtension createReturnExtension(String currentElement, String currentNamespace, Map<String, String> attributeMap, List<? extends PacketExtension> content)
+    protected HeadersExtension createReturnExtension(String currentElement, String currentNamespace,
-	{
+                    Map<String, String> attributeMap, List<? extends PacketExtension> content) {
-		return new HeadersExtension((Collection<Header>)content);
+        return new HeadersExtension((List<Header>) content);
     }
 
 }

smack-extensions/src/test/java/org/jivesoftware/smackx/shim/provider/HeadersProviderTest.java

@@ -0,0 +1,50 @@
+/**
+ *
+ * Copyright 2014 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.shim.provider;
+
+import static org.junit.Assert.assertEquals;
+
+
+import org.jivesoftware.smack.packet.Message;
+import org.jivesoftware.smack.test.util.TestUtils;
+import org.jivesoftware.smack.util.PacketParserUtils;
+import org.jivesoftware.smackx.shim.packet.Header;
+import org.jivesoftware.smackx.shim.packet.HeadersExtension;
+import org.junit.Test;
+import org.xmlpull.v1.XmlPullParser;
+
+public class HeadersProviderTest {
+
+    @Test
+    public void headersInMessageTest() throws Exception {
+        // @formatter:off
+        final String messageStanza = 
+          "<message from='romeo@shakespeare.lit/orchard' to='juliet@capulet.com' type='chat'>" +
+            "<body>Wherefore are thou?!?</body>" + 
+            "<headers xmlns='http://jabber.org/protocol/shim'>" +
+             "<header name='Urgency'>high</header>" +
+            "</headers>" +
+          "</message>";
+        // @formatter:on
+        XmlPullParser parser = TestUtils.getMessageParser(messageStanza);
+        Message message = PacketParserUtils.parseMessage(parser);
+        HeadersExtension headers = HeadersExtension.from(message);
+        Header header = headers.getHeaders().get(0);
+        assertEquals("Urgency", header.getName());
+        assertEquals("high", header.getValue());
+    }
+}