diff --git a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
index ac9bcc19d..8b6428de3 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/AbstractXMPPConnection.java
@@ -113,7 +113,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      * and reconnection events.
      */
     protected final Set<ConnectionListener> connectionListeners =
-            new CopyOnWriteArraySet<ConnectionListener>();
+            new CopyOnWriteArraySet<>();
 
     /**
      * A collection of StanzaCollectors which collects packets for a specified filter
@@ -142,7 +142,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      * List of PacketListeners that will be notified when a new stanza(/packet) was sent.
      */
     private final Map<StanzaListener, ListenerWrapper> sendListeners =
-            new HashMap<StanzaListener, ListenerWrapper>();
+            new HashMap<>();
 
     /**
      * List of PacketListeners that will be notified when a new stanza(/packet) is about to be
@@ -150,11 +150,11 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      * actually sent to the server.
      */
     private final Map<StanzaListener, InterceptorWrapper> interceptors =
-            new HashMap<StanzaListener, InterceptorWrapper>();
+            new HashMap<>();
 
     protected final Lock connectionLock = new ReentrantLock();
 
-    protected final Map<String, ExtensionElement> streamFeatures = new HashMap<String, ExtensionElement>();
+    protected final Map<String, ExtensionElement> streamFeatures = new HashMap<>();
 
     /**
      * The full JID of the authenticated user, as returned by the resource binding response of the server.
@@ -533,7 +533,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
 
 
         if (!hasFeature(Bind.ELEMENT, Bind.NAMESPACE)) {
-            // Server never offered resource binding, which is REQURIED in XMPP client and
+            // Server never offered resource binding, which is REQUIRED in XMPP client and
             // server implementations as per RFC6120 7.2
             throw new ResourceBindingNotOfferedException();
         }
@@ -592,7 +592,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
 
     /**
      * Get the name of the SASL mechanism that was used to authenticate this connection. This returns the name of
-     * mechanism which was used the last time this conneciton was authenticated, and will return <code>null</code> if
+     * mechanism which was used the last time this connection was authenticated, and will return <code>null</code> if
      * this connection was not authenticated before.
      * 
      * @return the name of the used SASL mechanism.
@@ -621,7 +621,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
             hostAddresses.add(hostAddress);
         }
         else if (config.host != null) {
-            hostAddresses = new ArrayList<HostAddress>(1);
+            hostAddresses = new ArrayList<>(1);
             HostAddress hostAddress = DNSUtil.getDNSResolver().lookupHostAddress(config.host, config.port, failedAddresses, config.getDnssecMode());
             if (hostAddress != null) {
                 hostAddresses.add(hostAddress);
@@ -862,7 +862,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
             debugger.onOutgoingStreamElement(packet);
         }
 
-        final List<StanzaListener> listenersToNotify = new LinkedList<StanzaListener>();
+        final List<StanzaListener> listenersToNotify = new LinkedList<>();
         synchronized (sendListeners) {
             for (ListenerWrapper listenerWrapper : sendListeners.values()) {
                 if (listenerWrapper.filterMatches(packet)) {
@@ -918,7 +918,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
      * @param packet the stanza(/packet) that is going to be sent to the server
      */
     private void firePacketInterceptors(Stanza packet) {
-        List<StanzaListener> interceptorsToInvoke = new LinkedList<StanzaListener>();
+        List<StanzaListener> interceptorsToInvoke = new LinkedList<>();
         synchronized (interceptors) {
             for (InterceptorWrapper interceptorWrapper : interceptors.values()) {
                 if (interceptorWrapper.filterMatches(packet)) {
@@ -1029,7 +1029,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
             final IQ iq = (IQ) packet;
             if (iq.isRequestIQ()) {
                 final String key = XmppStringUtils.generateKey(iq.getChildElementName(), iq.getChildElementNamespace());
-                IQRequestHandler iqRequestHandler = null;
+                IQRequestHandler iqRequestHandler;
                 final IQ.Type type = iq.getType();
                 switch (type) {
                 case set:
@@ -1112,7 +1112,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
         // First handle the async recv listeners. Note that this code is very similar to what follows a few lines below,
         // the only difference is that asyncRecvListeners is used here and that the packet listeners are started in
         // their own thread.
-        final Collection<StanzaListener> listenersToNotify = new LinkedList<StanzaListener>();
+        final Collection<StanzaListener> listenersToNotify = new LinkedList<>();
         synchronized (asyncRecvListeners) {
             for (ListenerWrapper listenerWrapper : asyncRecvListeners.values()) {
                 if (listenerWrapper.filterMatches(packet)) {
@@ -1342,7 +1342,7 @@ public abstract class AbstractXMPPConnection implements XMPPConnection {
             removeCallbacksService.shutdownNow();
             singleThreadedExecutorService.shutdownNow();
         } catch (Throwable t) {
-            LOGGER.log(Level.WARNING, "finalize() threw trhowable", t);
+            LOGGER.log(Level.WARNING, "finalize() threw throwable", t);
         }
         finally {
             super.finalize();
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java b/smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java
index 62b90f23f..7d7034d67 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/SmackFuture.java
@@ -84,7 +84,7 @@ public abstract class SmackFuture<V, E extends Exception> implements Future<V>,
         return this;
     }
 
-    private final V getOrThrowExecutionException() throws ExecutionException {
+    private V getOrThrowExecutionException() throws ExecutionException {
         assert (result != null || exception != null || cancelled);
         if (result != null) {
             return result;
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/XMPPConnection.java b/smack-core/src/main/java/org/jivesoftware/smack/XMPPConnection.java
index 393d9fdae..e90b6b8dc 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/XMPPConnection.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/XMPPConnection.java
@@ -78,7 +78,7 @@ public interface XMPPConnection {
      * 
      * @return the XMPP domain of this XMPP session.
      */
-    public DomainBareJid getXMPPServiceDomain();
+    DomainBareJid getXMPPServiceDomain();
 
     /**
      * Returns the host name of the server where the XMPP server is running. This would be the
@@ -86,7 +86,7 @@ public interface XMPPConnection {
      * 
      * @return the host name of the server where the XMPP server is running or null if not yet connected.
      */
-    public String getHost();
+    String getHost();
 
     /**
      * Returns the port number of the XMPP server for this connection. The default port
@@ -94,7 +94,7 @@ public interface XMPPConnection {
      * 
      * @return the port number of the XMPP server or 0 if not yet connected.
      */
-    public int getPort();
+    int getPort();
 
     /**
      * Returns the full XMPP address of the user that is logged in to the connection or
@@ -103,7 +103,7 @@ public interface XMPPConnection {
      * 
      * @return the full XMPP address of the user logged in.
      */
-    public EntityFullJid getUser();
+    EntityFullJid getUser();
 
     /**
      * Returns the stream ID for this connection, which is the value set by the server
@@ -113,35 +113,35 @@ public interface XMPPConnection {
      *      not connected to the server.
      * @see <a href="http://xmpp.org/rfcs/rfc6120.html#streams-attr-id">RFC 6120 § 4.7.3. id</a>
      */
-    public String getStreamId();
+    String getStreamId();
 
     /**
      * Returns true if currently connected to the XMPP server.
      * 
      * @return true if connected.
      */
-    public boolean isConnected();
+    boolean isConnected();
 
     /**
      * Returns true if currently authenticated by successfully calling the login method.
      * 
      * @return true if authenticated.
      */
-    public boolean isAuthenticated();
+    boolean isAuthenticated();
 
     /**
      * Returns true if currently authenticated anonymously.
      * 
      * @return true if authenticated anonymously.
      */
-    public boolean isAnonymous();
+    boolean isAnonymous();
 
     /**
      * Returns true if the connection to the server has successfully negotiated encryption. 
      * 
      * @return true if a secure connection to the server.
      */
-    public boolean isSecureConnection();
+    boolean isSecureConnection();
 
     /**
      * Returns true if network traffic is being compressed. When using stream compression network
@@ -151,7 +151,7 @@ public interface XMPPConnection {
      * 
      * @return true if network traffic is being compressed.
      */
-    public boolean isUsingCompression();
+    boolean isUsingCompression();
 
     /**
      * Sends the specified stanza to the server.
@@ -160,7 +160,7 @@ public interface XMPPConnection {
      * @throws NotConnectedException if the connection is not connected.
      * @throws InterruptedException
      * */
-    public void sendStanza(Stanza stanza) throws NotConnectedException, InterruptedException;
+    void sendStanza(Stanza stanza) throws NotConnectedException, InterruptedException;
 
     /**
      * Send a Nonza.
@@ -174,7 +174,7 @@ public interface XMPPConnection {
      * @throws NotConnectedException
      * @throws InterruptedException 
      */
-    public void sendNonza(Nonza nonza) throws NotConnectedException, InterruptedException;
+    void sendNonza(Nonza nonza) throws NotConnectedException, InterruptedException;
 
     /**
      * Adds a connection listener to this connection that will be notified when
@@ -182,14 +182,14 @@ public interface XMPPConnection {
      * 
      * @param connectionListener a connection listener.
      */
-    public void addConnectionListener(ConnectionListener connectionListener);
+    void addConnectionListener(ConnectionListener connectionListener);
 
     /**
      * Removes a connection listener from this connection.
      * 
      * @param connectionListener a connection listener.
      */
-    public void removeConnectionListener(ConnectionListener connectionListener);
+    void removeConnectionListener(ConnectionListener connectionListener);
 
     /**
      * Creates a new stanza(/packet) collector collecting packets that are replies to <code>packet</code>.
@@ -202,7 +202,7 @@ public interface XMPPConnection {
      * @throws NotConnectedException 
      * @throws InterruptedException 
      */
-    public StanzaCollector createStanzaCollectorAndSend(IQ packet) throws NotConnectedException, InterruptedException;
+    StanzaCollector createStanzaCollectorAndSend(IQ packet) throws NotConnectedException, InterruptedException;
 
     /**
      * Creates a new stanza(/packet) collector for this connection. A stanza(/packet) filter determines
@@ -216,7 +216,7 @@ public interface XMPPConnection {
      * @throws InterruptedException 
      * @throws NotConnectedException 
      */
-    public StanzaCollector createStanzaCollectorAndSend(StanzaFilter packetFilter, Stanza packet)
+    StanzaCollector createStanzaCollectorAndSend(StanzaFilter packetFilter, Stanza packet)
                     throws NotConnectedException, InterruptedException;
 
     /**
@@ -235,7 +235,7 @@ public interface XMPPConnection {
      * @param packetFilter the stanza(/packet) filter to use.
      * @return a new stanza(/packet) collector.
      */
-    public StanzaCollector createStanzaCollector(StanzaFilter packetFilter);
+    StanzaCollector createStanzaCollector(StanzaFilter packetFilter);
 
     /**
      * Create a new stanza(/packet) collector with the given stanza(/packet) collector configuration.
@@ -248,14 +248,14 @@ public interface XMPPConnection {
      * @return a new stanza(/packet) collector.
      * @since 4.1
      */
-    public StanzaCollector createStanzaCollector(StanzaCollector.Configuration configuration);
+    StanzaCollector createStanzaCollector(StanzaCollector.Configuration configuration);
 
     /**
      * Remove a stanza(/packet) collector of this connection.
      * 
      * @param collector a stanza(/packet) collectors which was created for this connection.
      */
-    public void removeStanzaCollector(StanzaCollector collector);
+    void removeStanzaCollector(StanzaCollector collector);
 
     /**
      * Registers a <b>synchronous</b> stanza(/packet) listener with this connection. A stanza(/packet) listener will be invoked only when
@@ -274,7 +274,7 @@ public interface XMPPConnection {
      * @see #addPacketInterceptor(StanzaListener, StanzaFilter)
      * @since 4.1
      */
-    public void addSyncStanzaListener(StanzaListener packetListener, StanzaFilter packetFilter);
+    void addSyncStanzaListener(StanzaListener packetListener, StanzaFilter packetFilter);
 
     /**
      * Removes a stanza(/packet) listener for received packets from this connection.
@@ -283,7 +283,7 @@ public interface XMPPConnection {
      * @return true if the stanza(/packet) listener was removed
      * @since 4.1
      */
-    public boolean removeSyncStanzaListener(StanzaListener packetListener);
+    boolean removeSyncStanzaListener(StanzaListener packetListener);
 
     /**
      * Registers an <b>asynchronous</b> stanza(/packet) listener with this connection. A stanza(/packet) listener will be invoked only
@@ -300,7 +300,7 @@ public interface XMPPConnection {
      * @see #addPacketInterceptor(StanzaListener, StanzaFilter)
      * @since 4.1
     */
-    public void addAsyncStanzaListener(StanzaListener packetListener, StanzaFilter packetFilter);
+    void addAsyncStanzaListener(StanzaListener packetListener, StanzaFilter packetFilter);
 
     /**
      * Removes an <b>asynchronous</b> stanza(/packet) listener for received packets from this connection.
@@ -309,7 +309,7 @@ public interface XMPPConnection {
      * @return true if the stanza(/packet) listener was removed
      * @since 4.1
      */
-    public boolean removeAsyncStanzaListener(StanzaListener packetListener);
+    boolean removeAsyncStanzaListener(StanzaListener packetListener);
 
     /**
      * Registers a stanza(/packet) listener with this connection. The listener will be
@@ -322,14 +322,14 @@ public interface XMPPConnection {
      * @param packetListener the stanza(/packet) listener to notify of sent packets.
      * @param packetFilter   the stanza(/packet) filter to use.
      */
-    public void addPacketSendingListener(StanzaListener packetListener, StanzaFilter packetFilter);
+    void addPacketSendingListener(StanzaListener packetListener, StanzaFilter packetFilter);
 
     /**
      * Removes a stanza(/packet) listener for sending packets from this connection.
      * 
      * @param packetListener the stanza(/packet) listener to remove.
      */
-    public void removePacketSendingListener(StanzaListener packetListener);
+    void removePacketSendingListener(StanzaListener packetListener);
 
     /**
      * Registers a stanza(/packet) interceptor with this connection. The interceptor will be
@@ -343,14 +343,14 @@ public interface XMPPConnection {
      * @param packetInterceptor the stanza(/packet) interceptor to notify of packets about to be sent.
      * @param packetFilter      the stanza(/packet) filter to use.
      */
-    public void addPacketInterceptor(StanzaListener packetInterceptor, StanzaFilter packetFilter);
+    void addPacketInterceptor(StanzaListener packetInterceptor, StanzaFilter packetFilter);
 
     /**
      * Removes a stanza(/packet) interceptor.
      *
      * @param packetInterceptor the stanza(/packet) interceptor to remove.
      */
-    public void removePacketInterceptor(StanzaListener packetInterceptor);
+    void removePacketInterceptor(StanzaListener packetInterceptor);
 
     /**
      * Returns the current value of the reply timeout in milliseconds for request for this
@@ -358,7 +358,7 @@ public interface XMPPConnection {
      *
      * @return the reply timeout in milliseconds
      */
-    public long getReplyTimeout();
+    long getReplyTimeout();
 
     /**
      * Set the stanza(/packet) reply timeout in milliseconds. In most cases, Smack will throw a
@@ -366,7 +366,7 @@ public interface XMPPConnection {
      *
      * @param timeout for a reply in milliseconds
      */
-    public void setReplyTimeout(long timeout);
+    void setReplyTimeout(long timeout);
 
     /**
      * Get the connection counter of this XMPPConnection instance. Those can be used as ID to
@@ -375,9 +375,9 @@ public interface XMPPConnection {
      *
      * @return the connection counter of this XMPPConnection
      */
-    public int getConnectionCounter();
+    int getConnectionCounter();
 
-    public static enum FromMode {
+    enum FromMode {
         /**
          * Leave the 'from' attribute unchanged. This is the behavior of Smack < 4.0
          */
@@ -400,14 +400,14 @@ public interface XMPPConnection {
      * 
      * @param fromMode
      */
-    public void setFromMode(FromMode fromMode);
+    void setFromMode(FromMode fromMode);
 
     /**
      * Get the currently active FromMode.
      *
      * @return the currently active {@link FromMode}
      */
-    public FromMode getFromMode();
+    FromMode getFromMode();
 
     /**
      * Get the feature stanza(/packet) extensions for a given stream feature of the
@@ -417,7 +417,7 @@ public interface XMPPConnection {
      * @param namespace
      * @return a stanza(/packet) extensions of the feature or <code>null</code>
      */
-    public <F extends ExtensionElement> F getFeature(String element, String namespace);
+    <F extends ExtensionElement> F getFeature(String element, String namespace);
 
     /**
      * Return true if the server supports the given stream feature.
@@ -426,7 +426,7 @@ public interface XMPPConnection {
      * @param namespace
      * @return true if the server supports the stream feature.
      */
-    public boolean hasFeature(String element, String namespace);
+    boolean hasFeature(String element, String namespace);
 
     /**
      * Send an IQ request asynchronously. The connection's default reply timeout will be used.
@@ -434,7 +434,7 @@ public interface XMPPConnection {
      * @param request the IQ request to send.
      * @return a SmackFuture for the response.
      */
-    public SmackFuture<IQ, Exception> sendIqRequestAsync(IQ request);
+    SmackFuture<IQ, Exception> sendIqRequestAsync(IQ request);
 
     /**
      * Send an IQ request asynchronously.
@@ -443,7 +443,7 @@ public interface XMPPConnection {
      * @param timeout the reply timeout in milliseconds.
      * @return a SmackFuture for the response.
      */
-    public SmackFuture<IQ, Exception> sendIqRequestAsync(IQ request, long timeout);
+    SmackFuture<IQ, Exception> sendIqRequestAsync(IQ request, long timeout);
 
     /**
      * Send a stanza asynchronously, waiting for exactly one response stanza using the given reply filter. The
@@ -453,7 +453,7 @@ public interface XMPPConnection {
      * @param replyFilter the filter used for the response stanza.
      * @return a SmackFuture for the response.
      */
-    public <S extends Stanza> SmackFuture<S, Exception> sendAsync(S stanza, StanzaFilter replyFilter);
+    <S extends Stanza> SmackFuture<S, Exception> sendAsync(S stanza, StanzaFilter replyFilter);
 
     /**
      * Send a stanza asynchronously, waiting for exactly one response stanza using the given reply filter.
@@ -463,7 +463,7 @@ public interface XMPPConnection {
      * @param timeout the reply timeout in milliseconds.
      * @return a SmackFuture for the response.
      */
-    public <S extends Stanza> SmackFuture<S, Exception> sendAsync(S stanza, StanzaFilter replyFilter, long timeout);
+    <S extends Stanza> SmackFuture<S, Exception> sendAsync(S stanza, StanzaFilter replyFilter, long timeout);
 
     /**
      * Send a stanza and wait asynchronously for a response by using <code>replyFilter</code>.
@@ -482,7 +482,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter,
+    void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter,
                     StanzaListener callback) throws NotConnectedException, InterruptedException;
 
     /**
@@ -503,7 +503,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter, StanzaListener callback,
+    void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter, StanzaListener callback,
                     @SuppressWarnings("deprecation") ExceptionCallback exceptionCallback) throws NotConnectedException, InterruptedException;
 
     /**
@@ -525,7 +525,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter,
+    void sendStanzaWithResponseCallback(Stanza stanza, StanzaFilter replyFilter,
                     final StanzaListener callback, @SuppressWarnings("deprecation") final ExceptionCallback exceptionCallback,
                     long timeout) throws NotConnectedException, InterruptedException;
 
@@ -542,7 +542,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendIqWithResponseCallback(IQ iqRequest, StanzaListener callback) throws NotConnectedException, InterruptedException;
+    void sendIqWithResponseCallback(IQ iqRequest, StanzaListener callback) throws NotConnectedException, InterruptedException;
 
     /**
      * Send a IQ stanza and invoke <code>callback</code> if there is a result of
@@ -561,7 +561,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendIqWithResponseCallback(IQ iqRequest, StanzaListener callback,
+    void sendIqWithResponseCallback(IQ iqRequest, StanzaListener callback,
                     @SuppressWarnings("deprecation") ExceptionCallback exceptionCallback) throws NotConnectedException, InterruptedException;
 
     /**
@@ -582,7 +582,7 @@ public interface XMPPConnection {
      */
     @Deprecated
     // TODO: Remove in Smack 4.4.
-    public void sendIqWithResponseCallback(IQ iqRequest, final StanzaListener callback,
+    void sendIqWithResponseCallback(IQ iqRequest, final StanzaListener callback,
                     @SuppressWarnings("deprecation") final ExceptionCallback exceptionCallback, long timeout)
                     throws NotConnectedException, InterruptedException;
 
@@ -593,7 +593,7 @@ public interface XMPPConnection {
      * @param callback the callback invoked once the stanza(/packet) filter matches a stanza.
      * @param packetFilter the filter to match stanzas or null to match all.
      */
-    public void addOneTimeSyncCallback(StanzaListener callback, StanzaFilter packetFilter);
+    void addOneTimeSyncCallback(StanzaListener callback, StanzaFilter packetFilter);
 
     /**
      * Register an IQ request handler with this connection.
@@ -603,7 +603,7 @@ public interface XMPPConnection {
      * @param iqRequestHandler the IQ request handler to register.
      * @return the previously registered IQ request handler or null.
      */
-    public IQRequestHandler registerIQRequestHandler(IQRequestHandler iqRequestHandler);
+    IQRequestHandler registerIQRequestHandler(IQRequestHandler iqRequestHandler);
 
     /**
      * Convenience method for {@link #unregisterIQRequestHandler(String, String, org.jivesoftware.smack.packet.IQ.Type)}.
@@ -611,7 +611,7 @@ public interface XMPPConnection {
      * @param iqRequestHandler
      * @return the previously registered IQ request handler or null.
      */
-    public IQRequestHandler unregisterIQRequestHandler(IQRequestHandler iqRequestHandler);
+    IQRequestHandler unregisterIQRequestHandler(IQRequestHandler iqRequestHandler);
 
     /**
      * Unregister an IQ request handler with this connection.
@@ -621,13 +621,13 @@ public interface XMPPConnection {
      * @param type the IQ type the IQ request handler is responsible for.
      * @return the previously registered IQ request handler or null.
      */
-    public IQRequestHandler unregisterIQRequestHandler(String element, String namespace, IQ.Type type);
+    IQRequestHandler unregisterIQRequestHandler(String element, String namespace, IQ.Type type);
 
     /**
      * Returns the timestamp in milliseconds when the last stanza was received.
      * 
      * @return the timestamp in milliseconds
      */
-    public long getLastStanzaReceived();
+    long getLastStanzaReceived();
 
 }
diff --git a/smack-core/src/main/java/org/jivesoftware/smack/util/ExceptionCallback.java b/smack-core/src/main/java/org/jivesoftware/smack/util/ExceptionCallback.java
index 52ffb4454..890b41d1d 100644
--- a/smack-core/src/main/java/org/jivesoftware/smack/util/ExceptionCallback.java
+++ b/smack-core/src/main/java/org/jivesoftware/smack/util/ExceptionCallback.java
@@ -18,6 +18,6 @@ package org.jivesoftware.smack.util;
 
 public interface ExceptionCallback<E> {
 
-    public void processException(E exception);
+    void processException(E exception);
 
 }
diff --git a/smack-experimental/src/test/java/org/jivesoftware/smackx/hashes/HashElementTest.java b/smack-experimental/src/test/java/org/jivesoftware/smackx/hashes/HashElementTest.java
index 26de91839..e67342a9e 100644
--- a/smack-experimental/src/test/java/org/jivesoftware/smackx/hashes/HashElementTest.java
+++ b/smack-experimental/src/test/java/org/jivesoftware/smackx/hashes/HashElementTest.java
@@ -49,8 +49,6 @@ public class HashElementTest extends SmackTestSuite {
         assertEquals("f4OxZX/x/FO5LcGBSKHWXfwtSx+j1ncoSt3SABJtkGk=", parsed.getHashB64());
         assertArrayEquals(HashManager.sha_256(message), parsed.getHash());
 
-        assertFalse(parsed.equals(expected));
-        assertFalse(parsed.equals(null));
         assertEquals(element, parsed);
         assertTrue(element.equals(parsed));
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/BytestreamManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/BytestreamManager.java
index 302cef86e..16e02249e 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/BytestreamManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/bytestreams/BytestreamManager.java
@@ -46,14 +46,14 @@ public interface BytestreamManager {
      * 
      * @param listener the listener to register
      */
-    public void addIncomingBytestreamListener(BytestreamListener listener);
+    void addIncomingBytestreamListener(BytestreamListener listener);
 
     /**
      * Removes the given listener from the list of listeners for all incoming bytestream requests.
      * 
      * @param listener the listener to remove
      */
-    public void removeIncomingBytestreamListener(BytestreamListener listener);
+    void removeIncomingBytestreamListener(BytestreamListener listener);
 
     /**
      * Adds {@link BytestreamListener} that is called for every incoming bytestream request unless
@@ -68,14 +68,14 @@ public interface BytestreamManager {
      * @param listener the listener to register
      * @param initiatorJID the JID of the user that wants to establish a bytestream
      */
-    public void addIncomingBytestreamListener(BytestreamListener listener, Jid initiatorJID);
+    void addIncomingBytestreamListener(BytestreamListener listener, Jid initiatorJID);
 
     /**
      * Removes the listener for the given user.
      * 
      * @param initiatorJID the JID of the user the listener should be removed
      */
-    public void removeIncomingBytestreamListener(Jid initiatorJID);
+    void removeIncomingBytestreamListener(Jid initiatorJID);
 
     /**
      * Establishes a bytestream with the given user and returns the session to send/receive data
@@ -97,7 +97,7 @@ public interface BytestreamManager {
      * @throws InterruptedException if the thread was interrupted while waiting in a blocking
      *         operation
      */
-    public BytestreamSession establishSession(Jid targetJID) throws XMPPException, IOException,
+    BytestreamSession establishSession(Jid targetJID) throws XMPPException, IOException,
                     InterruptedException, SmackException;
 
     /**
@@ -115,7 +115,7 @@ public interface BytestreamManager {
      * @throws InterruptedException if the thread was interrupted while waiting in a blocking
      *         operation
      */
-    public BytestreamSession establishSession(Jid targetJID, String sessionID)
+    BytestreamSession establishSession(Jid targetJID, String sessionID)
                     throws XMPPException, IOException, InterruptedException, SmackException;
 
 }
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandManager.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandManager.java
index a63a17bcf..4ab77757c 100755
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandManager.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/AdHocCommandManager.java
@@ -77,7 +77,7 @@ public final class AdHocCommandManager extends Manager {
      * Map an XMPPConnection with it AdHocCommandManager. This map have a key-value
      * pair for every active connection.
      */
-    private static Map<XMPPConnection, AdHocCommandManager> instances = new WeakHashMap<>();
+    private static final Map<XMPPConnection, AdHocCommandManager> instances = new WeakHashMap<>();
 
     /**
      * Register the listener for all the connection creations. When a new
@@ -114,7 +114,7 @@ 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<String, AdHocCommandInfo>();
+    private final Map<String, AdHocCommandInfo> commands = new ConcurrentHashMap<>();
 
     /**
      * Map a command session ID with the instance LocalCommand. The LocalCommand
@@ -122,7 +122,7 @@ 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<String, LocalCommand>();
+    private final Map<String, LocalCommand> executingCommands = new ConcurrentHashMap<>();
 
     private final ServiceDiscoveryManager serviceDiscoveryManager;
 
@@ -155,7 +155,7 @@ public final class AdHocCommandManager extends Manager {
                             @Override
                             public List<DiscoverItems.Item> getNodeItems() {
 
-                                List<DiscoverItems.Item> answer = new ArrayList<DiscoverItems.Item>();
+                                List<DiscoverItems.Item> answer = new ArrayList<>();
                                 Collection<AdHocCommandInfo> commandsList = getRegisteredCommands();
 
                                 for (AdHocCommandInfo info : commandsList) {
@@ -181,7 +181,7 @@ public final class AdHocCommandManager extends Manager {
                     return processAdHocCommand(requestData);
                 }
                 catch (InterruptedException | NoResponseException | NotConnectedException e) {
-                    LOGGER.log(Level.INFO, "processAdHocCommand threw exceptino", e);
+                    LOGGER.log(Level.INFO, "processAdHocCommand threw exception", e);
                     return null;
                 }
             }
@@ -215,7 +215,7 @@ public final class AdHocCommandManager extends Manager {
      * Registers a new command with this command manager, which is related to a
      * connection. The <tt>node</tt> is an unique identifier of that
      * command for the connection related to this command manager. The <tt>name</tt>
-     * is the human readeale name of the command. The <tt>factory</tt> generates
+     * is the human readable name of the command. The <tt>factory</tt> generates
      * new instances of the command.
      *
      * @param node the unique identifier of the command.
@@ -232,7 +232,7 @@ public final class AdHocCommandManager extends Manager {
                 new AbstractNodeInformationProvider() {
                     @Override
                     public List<String> getNodeFeatures() {
-                        List<String> answer = new ArrayList<String>();
+                        List<String> answer = new ArrayList<>();
                         answer.add(NAMESPACE);
                         // TODO: check if this service is provided by the
                         // TODO: current connection.
@@ -241,7 +241,7 @@ public final class AdHocCommandManager extends Manager {
                     }
                     @Override
                     public List<DiscoverInfo.Identity> getNodeIdentities() {
-                        List<DiscoverInfo.Identity> answer = new ArrayList<DiscoverInfo.Identity>();
+                        List<DiscoverInfo.Identity> answer = new ArrayList<>();
                         DiscoverInfo.Identity identity = new DiscoverInfo.Identity(
                                 "automation", name, "command-node");
                         answer.add(identity);
@@ -353,7 +353,7 @@ public final class AdHocCommandManager extends Manager {
 
             try {
                 // Create a new instance of the command with the
-                // corresponding sessioid
+                // corresponding sessionid
                 LocalCommand command;
                 try {
                     command = newInstanceOfCmd(commandNode, sessionId);
@@ -425,7 +425,7 @@ public final class AdHocCommandManager extends Manager {
                                             // the requester know why his execution request is
                                             // not accepted. If the session is removed just
                                             // after the time out, then whe the user request to
-                                            // continue the execution he will recieved an
+                                            // continue the execution he will received an
                                             // invalid session error and not a time out error.
                                             if (System.currentTimeMillis() - creationStamp > SESSION_TIMEOUT * 1000 * 2) {
                                                 // Remove the expired session
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/LocalCommandFactory.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/LocalCommandFactory.java
index d8248e0ef..84fd2b876 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/LocalCommandFactory.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/commands/LocalCommandFactory.java
@@ -41,6 +41,6 @@ public interface LocalCommandFactory {
      * @throws InvocationTargetException 
      * @throws IllegalArgumentException 
      */
-    public LocalCommand getInstance() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException;
+    LocalCommand getInstance() throws InstantiationException, IllegalAccessException, IllegalArgumentException, InvocationTargetException, NoSuchMethodException, SecurityException;
 
 }
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/filetransfer/IncomingFileTransfer.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/filetransfer/IncomingFileTransfer.java
index ff73258b7..c29d16c99 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/filetransfer/IncomingFileTransfer.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/filetransfer/IncomingFileTransfer.java
@@ -182,7 +182,7 @@ public class IncomingFileTransfer extends FileTransfer {
         final StreamNegotiator streamNegotiator = negotiator
                 .selectStreamNegotiator(receiveRequest);
         setStatus(Status.negotiating_stream);
-        FutureTask<InputStream> streamNegotiatorTask = new FutureTask<InputStream>(
+        FutureTask<InputStream> streamNegotiatorTask = new FutureTask<>(
                 new Callable<InputStream>() {
 
                     @Override
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/Jingle.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/Jingle.java
index 12c2e4d5e..cddda3984 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/Jingle.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/Jingle.java
@@ -94,7 +94,7 @@ public final class Jingle extends IQ {
 
     /**
      * Get the responder. The responder is the full JID of the entity that has replied to the initiation (which may be
-     * different to the "to" addresss in the IQ).
+     * different to the "to" address in the IQ).
      *
      * @return the responder
      */
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleAction.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleAction.java
index edd2e8033..7b1beb719 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleAction.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/element/JingleAction.java
@@ -44,7 +44,7 @@ public enum JingleAction {
     transport_replace,
     ;
 
-    private static final Map<String, JingleAction> map = new HashMap<String, JingleAction>(
+    private static final Map<String, JingleAction> map = new HashMap<>(
                     JingleAction.values().length);
     static {
         for (JingleAction jingleAction : JingleAction.values()) {
@@ -54,7 +54,7 @@ public enum JingleAction {
 
     private final String asString;
 
-    private JingleAction() {
+    JingleAction() {
         asString = this.name().replace('_', '-');
     }
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportInitiationException.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportInitiationException.java
index 8971d2821..a9cfee017 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportInitiationException.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportInitiationException.java
@@ -16,9 +16,6 @@
  */
 package org.jivesoftware.smackx.jingle.transports;
 
-/**
- * Created by vanitas on 25.06.17.
- */
 public abstract class JingleTransportInitiationException extends Exception {
     private static final long serialVersionUID = 1L;
 
diff --git a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportSession.java b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportSession.java
index 0776bc6b2..004379f8e 100644
--- a/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportSession.java
+++ b/smack-extensions/src/main/java/org/jivesoftware/smackx/jingle/transports/JingleTransportSession.java
@@ -22,9 +22,6 @@ import org.jivesoftware.smackx.jingle.element.Jingle;
 import org.jivesoftware.smackx.jingle.element.JingleContent;
 import org.jivesoftware.smackx.jingle.element.JingleContentTransport;
 
-/**
- * Created by vanitas on 20.06.17.
- */
 public abstract class JingleTransportSession<T extends JingleContentTransport> {
     protected final JingleSession jingleSession;
     protected T ourProposal, theirProposal;
diff --git a/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleUtilTest.java b/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleUtilTest.java
index 500ee2279..e10a879f2 100644
--- a/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleUtilTest.java
+++ b/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/JingleUtilTest.java
@@ -98,5 +98,6 @@ public class JingleUtilTest extends SmackTestSuite {
                         "</content>" +
                     "</jingle>" +
                 "</iq>";
+        // TODO: Finish test
     }
 }
diff --git a/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/provider/JingleProviderTest.java b/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/provider/JingleProviderTest.java
index c3483623e..68eb4ab57 100644
--- a/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/provider/JingleProviderTest.java
+++ b/smack-extensions/src/test/java/org/jivesoftware/smackx/jingle/provider/JingleProviderTest.java
@@ -55,8 +55,8 @@ public class JingleProviderTest {
 
         JingleContentDescription jingleContentDescription = jingle.getSoleContentOrThrow().getDescription();
 
-        String parsedUnknownJingleContentDescrptionNamespace = jingleContentDescription.getNamespace();
-        assertEquals(unknownJingleContentDescriptionNamespace, parsedUnknownJingleContentDescrptionNamespace);
+        String parsedUnknownJingleContentDescriptionNamespace = jingleContentDescription.getNamespace();
+        assertEquals(unknownJingleContentDescriptionNamespace, parsedUnknownJingleContentDescriptionNamespace);
     }
 
     @Test
diff --git a/smack-integration-test/src/main/java/org/jivesoftware/smackx/xdata/FormTest.java b/smack-integration-test/src/main/java/org/jivesoftware/smackx/xdata/FormTest.java
index 706b44318..fd8097f87 100644
--- a/smack-integration-test/src/main/java/org/jivesoftware/smackx/xdata/FormTest.java
+++ b/smack-integration-test/src/main/java/org/jivesoftware/smackx/xdata/FormTest.java
@@ -104,8 +104,8 @@ public class FormTest extends AbstractSmackIntegrationTest {
             chat.sendMessage(msg);
 
             // Get the message with the form to fill out
-            Message msg2 = (Message) collector2.nextResult();
-            assertNotNull("Messge not found", msg2);
+            Message msg2 = collector2.nextResult();
+            assertNotNull("Message not found", msg2);
             // Retrieve the form to fill out
             Form formToRespond = Form.getFormFrom(msg2);
             assertNotNull(formToRespond);
@@ -140,8 +140,8 @@ public class FormTest extends AbstractSmackIntegrationTest {
             conTwo.sendStanza(msg2);
 
             // Get the message with the completed form
-            Message msg3 = (Message) collector.nextResult();
-            assertNotNull("Messge not found", msg3);
+            Message msg3 = collector.nextResult();
+            assertNotNull("Message not found", msg3);
             // Retrieve the completed form
             completedForm = Form.getFormFrom(msg3);
             assertNotNull(completedForm);