Java tutorial
/** * $RCSfile$ * $Revision$ * $Date$ * * Copyright 2003-2007 Jive Software. * * All rights reserved. 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.smack; import android.util.Log; import org.androidpn.client.LogUtil; import org.androidpn.client.XmppManager; import org.apache.harmony.javax.security.auth.callback.Callback; import org.apache.harmony.javax.security.auth.callback.CallbackHandler; import org.apache.harmony.javax.security.auth.callback.PasswordCallback; import org.apache.http.conn.util.InetAddressUtils; import org.jivesoftware.smack.filter.PacketFilter; import org.jivesoftware.smack.packet.Packet; import org.jivesoftware.smack.packet.Presence; import org.jivesoftware.smack.packet.XMPPError; import org.jivesoftware.smack.util.StringUtils; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.ByteArrayInputStream; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.lang.reflect.Constructor; import java.lang.reflect.Method; import java.net.InetAddress; import java.net.Socket; import java.net.UnknownHostException; import java.security.KeyStore; import java.security.Provider; import java.security.Security; import java.util.Collection; import javax.net.ssl.KeyManager; import javax.net.ssl.KeyManagerFactory; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSocket; /** * Creates a socket connection to a XMPP server. This is the default connection * to a Jabber server and is specified in the XMPP Core (RFC 3920). * * @see org.jivesoftware.smack.Connection * @author Matt Tucker */ public class XMPPConnection extends Connection { private static final String LOG_TAG = LogUtil.makeLogTag(XMPPConnection.class); /** * The socket which is used for this connection. */ protected Socket socket; String connectionID = null; private String user = null; private boolean connected = false; /** * Flag that indicates if the user is currently authenticated with the server. */ private boolean authenticated = false; /** * Flag that indicates if the user was authenticated with the server when the connection * to the server was closed (abruptly or not). */ private boolean wasAuthenticated = false; private boolean anonymous = false; private boolean usingTLS = false; PacketWriter packetWriter; PacketReader packetReader; Roster roster = null; /** * Collection of available stream compression methods offered by the server. */ private Collection<String> compressionMethods; /** * Flag that indicates if stream compression is actually in use. */ private boolean usingCompression; /** * Creates a new connection to the specified XMPP server. A DNS SRV lookup will be * performed to determine the IP address and port corresponding to the * service name; if that lookup fails, it's assumed that server resides at * <tt>serviceName</tt> with the default port of 5222. Encrypted connections (TLS) * will be used if available, stream compression is disabled, and standard SASL * mechanisms will be used for authentication.<p> * <p/> * This is the simplest constructor for connecting to an XMPP server. Alternatively, * you can get fine-grained control over connection settings using the * {@link #XMPPConnection(ConnectionConfiguration)} constructor.<p> * <p/> * Note that XMPPConnection constructors do not establish a connection to the server * and you must call {@link #connect()}.<p> * <p/> * The CallbackHandler will only be used if the connection requires the client provide * an SSL certificate to the server. The CallbackHandler must handle the PasswordCallback * to prompt for a password to unlock the keystore containing the SSL certificate. * * @param serviceName the name of the XMPP server to connect to; e.g. <tt>example.com</tt>. * @param callbackHandler the CallbackHandler used to prompt for the password to the keystore. */ public XMPPConnection(String serviceName, CallbackHandler callbackHandler) { // Create the configuration for this new connection super(new ConnectionConfiguration(serviceName)); config.setCompressionEnabled(false); config.setSASLAuthenticationEnabled(true); config.setDebuggerEnabled(DEBUG_ENABLED); config.setCallbackHandler(callbackHandler); } /** * Creates a new XMPP conection in the same way {@link #XMPPConnection(String, org.apache.harmony.javax.security.auth.callback.CallbackHandler)} does, but * with no callback handler for password prompting of the keystore. This will work * in most cases, provided the client is not required to provide a certificate to * the server. * * @param serviceName the name of the XMPP server to connect to; e.g. <tt>example.com</tt>. */ public XMPPConnection(String serviceName) { // Create the configuration for this new connection super(new ConnectionConfiguration(serviceName)); config.setCompressionEnabled(false); config.setSASLAuthenticationEnabled(true); config.setDebuggerEnabled(DEBUG_ENABLED); } /** * Creates a new XMPP conection in the same way {@link #XMPPConnection(ConnectionConfiguration, org.apache.harmony.javax.security.auth.callback.CallbackHandler)} does, but * with no callback handler for password prompting of the keystore. This will work * in most cases, provided the client is not required to provide a certificate to * the server. * * * @param config the connection configuration. */ public XMPPConnection(ConnectionConfiguration config) { super(config); } /** * Creates a new XMPP connection using the specified connection configuration.<p> * <p/> * Manually specifying connection configuration information is suitable for * advanced users of the API. In many cases, using the * {@link #XMPPConnection(String)} constructor is a better approach.<p> * <p/> * Note that XMPPConnection constructors do not establish a connection to the server * and you must call {@link #connect()}.<p> * <p/> * * The CallbackHandler will only be used if the connection requires the client provide * an SSL certificate to the server. The CallbackHandler must handle the PasswordCallback * to prompt for a password to unlock the keystore containing the SSL certificate. * * @param config the connection configuration. * @param callbackHandler the CallbackHandler used to prompt for the password to the keystore. */ public XMPPConnection(ConnectionConfiguration config, CallbackHandler callbackHandler) { super(config); config.setCallbackHandler(callbackHandler); } public String getConnectionID() { if (!isConnected()) { return null; } return connectionID; } public String getUser() { if (!isAuthenticated()) { return null; } return user; } /** * Logs in to the server using the strongest authentication mode supported by * the server. If the server supports SASL authentication then the user will be * authenticated using SASL if not Non-SASL authentication will be tried. If more than * five seconds (default timeout) elapses in each step of the authentication process * without a response from the server, or if an error occurs, a XMPPException will be * thrown.<p> * * Before logging in (i.e. authenticate) to the server the connection must be connected. * For compatibility and easiness of use the connection will automatically connect to the * server if not already connected.<p> * * It is possible to log in without sending an initial available presence by using * {@link ConnectionConfiguration#setSendPresence(boolean)}. If this connection is * not interested in loading its roster upon login then use * {@link ConnectionConfiguration#setRosterLoadedAtLogin(boolean)}. * Finally, if you want to not pass a password and instead use a more advanced mechanism * while using SASL then you may be interested in using * {@link ConnectionConfiguration#setCallbackHandler(javax.security.auth.callback.CallbackHandler)}. * For more advanced login settings see {@link ConnectionConfiguration}. * * @param username the username. * @param password the password or <tt>null</tt> if using a CallbackHandler. * @param resource the resource. * @throws org.jivesoftware.smack.XMPPException if an error occurs. * @throws IllegalStateException if not connected to the server, or already logged in * to the serrver. */ public synchronized void login(String username, String password, String resource) throws XMPPException { if (!isConnected()) { throw new IllegalStateException("Not connected to server."); } if (authenticated) { throw new IllegalStateException("Already logged in to server."); } // Do partial version of nameprep on the username. username = username.toLowerCase().trim(); String response; if (config.isSASLAuthenticationEnabled() && saslAuthentication.hasNonAnonymousAuthentication()) { // Authenticate using SASL if (password != null) { response = saslAuthentication.authenticate(username, password, resource); } else { response = saslAuthentication.authenticate(username, resource, config.getCallbackHandler()); } } else { // Authenticate using Non-SASL response = new NonSASLAuthentication(this).authenticate(username, password, resource); } // Set the user. if (response != null) { this.user = response; // Update the serviceName with the one returned by the server config.setServiceName(StringUtils.parseServer(response)); } else { this.user = username + "@" + getServiceName(); if (resource != null) { this.user += "/" + resource; } } // If compression is enabled then request the server to use stream compression if (config.isCompressionEnabled()) { useCompression(); } // Create the roster if it is not a reconnection. if (this.roster == null) { if (rosterStorage == null) { this.roster = new Roster(this); } else { this.roster = new Roster(this, rosterStorage); } } if (config.isRosterLoadedAtLogin()) { this.roster.reload(); } // Set presence to online. if (config.isSendPresence()) { packetWriter.sendPacket(new Presence(Presence.Type.available)); } // Indicate that we're now authenticated. authenticated = true; anonymous = false; // Stores the autentication for future reconnection config.setLoginInfo(username, password, resource); // If debugging is enabled, change the the debug window title to include the // name we are now logged-in as. // If DEBUG_ENABLED was set to true AFTER the connection was created the debugger // will be null if (config.isDebuggerEnabled() && debugger != null) { debugger.userHasLogged(user); } } /** * Logs in to the server anonymously. Very few servers are configured to support anonymous * authentication, so it's fairly likely logging in anonymously will fail. If anonymous login * does succeed, your XMPP address will likely be in the form "server/123ABC" (where "123ABC" * is a random value generated by the server). * * @throws org.jivesoftware.smack.XMPPException if an error occurs or anonymous logins are not supported by the server. * @throws IllegalStateException if not connected to the server, or already logged in * to the serrver. */ public synchronized void loginAnonymously() throws XMPPException { if (!isConnected()) { throw new IllegalStateException("Not connected to server."); } if (authenticated) { throw new IllegalStateException("Already logged in to server."); } String response; if (config.isSASLAuthenticationEnabled() && saslAuthentication.hasAnonymousAuthentication()) { response = saslAuthentication.authenticateAnonymously(); } else { // Authenticate using Non-SASL response = new NonSASLAuthentication(this).authenticateAnonymously(); } // Set the user value. this.user = response; // Update the serviceName with the one returned by the server config.setServiceName(StringUtils.parseServer(response)); // If compression is enabled then request the server to use stream compression if (config.isCompressionEnabled()) { useCompression(); } // Anonymous users can't have a roster. roster = null; // Set presence to online. packetWriter.sendPacket(new Presence(Presence.Type.available)); // Indicate that we're now authenticated. authenticated = true; anonymous = true; // If debugging is enabled, change the the debug window title to include the // name we are now logged-in as. // If DEBUG_ENABLED was set to true AFTER the connection was created the debugger // will be null if (config.isDebuggerEnabled() && debugger != null) { debugger.userHasLogged(user); } } public Roster getRoster() { if (roster == null) { return null; } // If this is the first time the user has asked for the roster after calling // login, we want to wait for the server to send back the user's roster. This // behavior shields API users from having to worry about the fact that roster // operations are asynchronous, although they'll still have to listen for // changes to the roster. Note: because of this waiting logic, internal // Smack code should be wary about calling the getRoster method, and may need to // access the roster object directly. if (!roster.rosterInitialized) { try { synchronized (roster) { long waitTime = SmackConfiguration.getPacketReplyTimeout(); long start = System.currentTimeMillis(); while (!roster.rosterInitialized) { if (waitTime <= 0) { break; } roster.wait(waitTime); long now = System.currentTimeMillis(); waitTime -= now - start; start = now; } } } catch (InterruptedException ie) { // Ignore. } } return roster; } public boolean isConnected() { return connected; } public boolean isSecureConnection() { return isUsingTLS(); } public boolean isAuthenticated() { return authenticated; } public boolean isAnonymous() { return anonymous; } /** * Closes the connection by setting presence to unavailable then closing the stream to * the XMPP server. The shutdown logic will be used during a planned disconnection or when * dealing with an unexpected disconnection. Unlike {@link #disconnect()} the connection's * packet reader, packet writer, and {@link org.jivesoftware.smack.Roster} will not be removed; thus * connection's state is kept. * * @param unavailablePresence the presence packet to send during shutdown. */ protected void shutdown(Presence unavailablePresence) { // Set presence to offline. Log.d(LOG_TAG, "shutdown"); if (packetWriter != null) { packetWriter.sendPacket(unavailablePresence); } this.setWasAuthenticated(authenticated); authenticated = false; connected = false; if (packetReader != null) { packetReader.shutdown(); } if (packetWriter != null) { packetWriter.shutdown(); } // Wait 150 ms for processes to clean-up, then shutdown. try { Thread.sleep(150); } catch (Exception e) { // Ignore. } // Close down the readers and writers. if (reader != null) { try { reader.close(); } catch (Throwable ignore) { /* ignore */ } reader = null; } if (writer != null) { try { writer.close(); } catch (Throwable ignore) { /* ignore */ } writer = null; } try { socket.close(); } catch (Exception e) { // Ignore. } saslAuthentication.init(); } public void disconnect(Presence unavailablePresence) { Log.d(LOG_TAG, "disconnect"); // If not connected, ignore this request. if (packetReader == null || packetWriter == null) { return; } shutdown(unavailablePresence); if (roster != null) { roster.cleanup(); roster = null; } wasAuthenticated = false; packetWriter.cleanup(); packetWriter = null; packetReader.cleanup(); packetReader = null; } public void sendPacket(Packet packet) { if (!isConnected()) { throw new IllegalStateException("Not connected to server."); } if (packet == null) { throw new NullPointerException("Packet is null."); } packetWriter.sendPacket(packet); } /** * Registers a packet interceptor with this connection. The interceptor will be * invoked every time a packet is about to be sent by this connection. Interceptors * may modify the packet to be sent. A packet filter determines which packets * will be delivered to the interceptor. * * @param packetInterceptor the packet interceptor to notify of packets about to be sent. * @param packetFilter the packet filter to use. * @deprecated replaced by {@link org.jivesoftware.smack.Connection#addPacketInterceptor(PacketInterceptor, org.jivesoftware.smack.filter.PacketFilter)}. */ public void addPacketWriterInterceptor(PacketInterceptor packetInterceptor, PacketFilter packetFilter) { addPacketInterceptor(packetInterceptor, packetFilter); } /** * Removes a packet interceptor. * * @param packetInterceptor the packet interceptor to remove. * @deprecated replaced by {@link org.jivesoftware.smack.Connection#removePacketInterceptor(PacketInterceptor)}. */ public void removePacketWriterInterceptor(PacketInterceptor packetInterceptor) { removePacketInterceptor(packetInterceptor); } /** * Registers a packet listener with this connection. The listener will be * notified of every packet that this connection sends. A packet filter determines * which packets will be delivered to the listener. Note that the thread * that writes packets will be used to invoke the listeners. Therefore, each * packet listener should complete all operations quickly or use a different * thread for processing. * * @param packetListener the packet listener to notify of sent packets. * @param packetFilter the packet filter to use. * @deprecated replaced by {@link #addPacketSendingListener(org.jivesoftware.smack.PacketListener, org.jivesoftware.smack.filter.PacketFilter)}. */ public void addPacketWriterListener(PacketListener packetListener, PacketFilter packetFilter) { addPacketSendingListener(packetListener, packetFilter); } /** * Removes a packet listener for sending packets from this connection. * * @param packetListener the packet listener to remove. * @deprecated replaced by {@link #removePacketSendingListener(org.jivesoftware.smack.PacketListener)}. */ public void removePacketWriterListener(PacketListener packetListener) { removePacketSendingListener(packetListener); } private void connectUsingConfiguration(ConnectionConfiguration config) throws XMPPException { String host = config.getHost(); int port = config.getPort(); try { if (config.getSocketFactory() == null) { this.socket = new Socket(host, port); } else { this.socket = config.getSocketFactory().createSocket(host, port); } } catch (UnknownHostException uhe) { String errorMessage = "Could not connect to " + host + ":" + port + "."; throw new XMPPException(errorMessage, new XMPPError(XMPPError.Condition.remote_server_timeout, errorMessage), uhe); } catch (IOException ioe) { String errorMessage = "XMPPError connecting to " + host + ":" + port + "."; throw new XMPPException(errorMessage, new XMPPError(XMPPError.Condition.remote_server_error, errorMessage), ioe); } initConnection(); } /** * Initializes the connection by creating a packet reader and writer and opening a * XMPP stream to the server. * * @throws org.jivesoftware.smack.XMPPException if establishing a connection to the server fails. */ private void initConnection() throws XMPPException { boolean isFirstInitialization = packetReader == null || packetWriter == null; if (!isFirstInitialization) { usingCompression = false; } // Set the reader and writer instance variables initReaderAndWriter(); try { if (isFirstInitialization) { packetWriter = new PacketWriter(this); packetReader = new PacketReader(this); // If debugging is enabled, we should start the thread that will listen for // all packets and then log them. if (config.isDebuggerEnabled()) { addPacketListener(debugger.getReaderListener(), null); if (debugger.getWriterListener() != null) { addPacketSendingListener(debugger.getWriterListener(), null); } } } else { packetWriter.init(); packetReader.init(); } // Start the packet writer. This will open a XMPP stream to the server packetWriter.startup(); // Start the packet reader. The startup() method will block until we // get an opening stream packet back from server. packetReader.startup(); // Make note of the fact that we're now connected. connected = true; // Start keep alive process (after TLS was negotiated - if available) if (isFirstInitialization) { // Notify listeners that a new connection has been established for (ConnectionCreationListener listener : getConnectionCreationListeners()) { listener.connectionCreated(this); } } else if (!wasAuthenticated) { packetReader.notifyReconnection(); } } catch (XMPPException ex) { // An exception occurred in setting up the connection. Make sure we shut down the // readers and writers and close the socket. if (packetWriter != null) { try { packetWriter.shutdown(); } catch (Throwable ignore) { /* ignore */ } packetWriter = null; } if (packetReader != null) { try { packetReader.shutdown(); } catch (Throwable ignore) { /* ignore */ } packetReader = null; } if (reader != null) { try { reader.close(); } catch (Throwable ignore) { /* ignore */ } reader = null; } if (writer != null) { try { writer.close(); } catch (Throwable ignore) { /* ignore */} writer = null; } if (socket != null) { try { socket.close(); } catch (Exception e) { /* ignore */ } socket = null; } this.setWasAuthenticated(authenticated); authenticated = false; connected = false; throw ex; // Everything stoppped. Now throw the exception. } } private void initReaderAndWriter() throws XMPPException { try { if (!usingCompression) { reader = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8")); writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8")); } else { try { Class<?> zoClass = Class.forName("com.jcraft.jzlib.ZOutputStream"); Constructor<?> constructor = zoClass.getConstructor(OutputStream.class, Integer.TYPE); Object out = constructor.newInstance(socket.getOutputStream(), 9); Method method = zoClass.getMethod("setFlushMode", Integer.TYPE); method.invoke(out, 2); writer = new BufferedWriter(new OutputStreamWriter((OutputStream) out, "UTF-8")); Class<?> ziClass = Class.forName("com.jcraft.jzlib.ZInputStream"); constructor = ziClass.getConstructor(InputStream.class); Object in = constructor.newInstance(socket.getInputStream()); method = ziClass.getMethod("setFlushMode", Integer.TYPE); method.invoke(in, 2); reader = new BufferedReader(new InputStreamReader((InputStream) in, "UTF-8")); } catch (Exception e) { e.printStackTrace(); reader = new BufferedReader(new InputStreamReader(socket.getInputStream(), "UTF-8")); writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream(), "UTF-8")); } } } catch (IOException ioe) { throw new XMPPException("XMPPError establishing connection with server.", new XMPPError(XMPPError.Condition.remote_server_error, "XMPPError establishing connection with server."), ioe); } // If debugging is enabled, we open a window and write out all network traffic. initDebugger(); } /*********************************************** * TLS code below **********************************************/ /** * Returns true if the connection to the server has successfully negotiated TLS. Once TLS * has been negotiatied the connection has been secured. * * @return true if the connection to the server has successfully negotiated TLS. */ public boolean isUsingTLS() { return usingTLS; } /** * Notification message saying that the server supports TLS so confirm the server that we * want to secure the connection. * * @param required true when the server indicates that TLS is required. */ void startTLSReceived(boolean required) { if (required && config.getSecurityMode() == ConnectionConfiguration.SecurityMode.disabled) { packetReader.notifyConnectionError(new IllegalStateException( "TLS required by server but not allowed by connection configuration")); return; } if (config.getSecurityMode() == ConnectionConfiguration.SecurityMode.disabled) { // Do not secure the connection using TLS since TLS was disabled return; } try { writer.write("<starttls xmlns=\"urn:ietf:params:xml:ns:xmpp-tls\"/>"); writer.flush(); } catch (IOException e) { packetReader.notifyConnectionError(e); } } /** * The server has indicated that TLS negotiation can start. We now need to secure the * existing plain connection and perform a handshake. This method won't return until the * connection has finished the handshake or an error occured while securing the connection. * * @throws Exception if an exception occurs. */ void proceedTLSReceived() throws Exception { SSLContext context = SSLContext.getInstance("TLS"); KeyStore ks = null; KeyManager[] kms = null; PasswordCallback pcb = null; if (config.getCallbackHandler() == null) { ks = null; } else { //System.out.println("Keystore type: "+configuration.getKeystoreType()); if (config.getKeystoreType().equals("NONE")) { ks = null; pcb = null; } else if (config.getKeystoreType().equals("PKCS11")) { try { Constructor c = Class.forName("sun.security.pkcs11.SunPKCS11") .getConstructor(InputStream.class); String pkcs11Config = "name = SmartCard\nlibrary = " + config.getPKCS11Library(); ByteArrayInputStream config = new ByteArrayInputStream(pkcs11Config.getBytes()); Provider p = (Provider) c.newInstance(config); Security.addProvider(p); ks = KeyStore.getInstance("PKCS11", p); pcb = new PasswordCallback("PKCS11 Password: ", false); this.config.getCallbackHandler().handle(new Callback[] { pcb }); ks.load(null, pcb.getPassword()); } catch (Exception e) { ks = null; pcb = null; } } else if (config.getKeystoreType().equals("Apple")) { ks = KeyStore.getInstance("KeychainStore", "Apple"); ks.load(null, null); //pcb = new PasswordCallback("Apple Keychain",false); //pcb.setPassword(null); } else { ks = KeyStore.getInstance(config.getKeystoreType()); try { pcb = new PasswordCallback("Keystore Password: ", false); config.getCallbackHandler().handle(new Callback[] { pcb }); ks.load(new FileInputStream(config.getKeystorePath()), pcb.getPassword()); } catch (Exception e) { ks = null; pcb = null; } } KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509"); try { if (pcb == null) { kmf.init(ks, null); } else { kmf.init(ks, pcb.getPassword()); pcb.clearPassword(); } kms = kmf.getKeyManagers(); } catch (NullPointerException npe) { kms = null; } } // Verify certificate presented by the server context.init(kms, new javax.net.ssl.TrustManager[] { new ServerTrustManager(getServiceName(), config) }, new java.security.SecureRandom()); Socket plain = socket; // Secure the plain connection socket = context.getSocketFactory().createSocket(plain, plain.getInetAddress().getHostName(), plain.getPort(), true); socket.setSoTimeout(0); socket.setKeepAlive(true); // Initialize the reader and writer with the new secured version initReaderAndWriter(); // Proceed to do the handshake ((SSLSocket) socket).startHandshake(); //if (((SSLSocket) socket).getWantClientAuth()) { // System.err.println("Connection wants client auth"); //} //else if (((SSLSocket) socket).getNeedClientAuth()) { // System.err.println("Connection needs client auth"); //} //else { // System.err.println("Connection does not require client auth"); // } // Set that TLS was successful usingTLS = true; // Set the new writer to use packetWriter.setWriter(writer); // Send a new opening stream to the server packetWriter.openStream(); } /** * Sets the available stream compression methods offered by the server. * * @param methods compression methods offered by the server. */ void setAvailableCompressionMethods(Collection<String> methods) { compressionMethods = methods; } /** * Returns true if the specified compression method was offered by the server. * * @param method the method to check. * @return true if the specified compression method was offered by the server. */ private boolean hasAvailableCompressionMethod(String method) { return compressionMethods != null && compressionMethods.contains(method); } public boolean isUsingCompression() { return usingCompression; } /** * Starts using stream compression that will compress network traffic. Traffic can be * reduced up to 90%. Therefore, stream compression is ideal when using a slow speed network * connection. However, the server and the client will need to use more CPU time in order to * un/compress network data so under high load the server performance might be affected.<p> * <p/> * Stream compression has to have been previously offered by the server. Currently only the * zlib method is supported by the client. Stream compression negotiation has to be done * before authentication took place.<p> * <p/> * Note: to use stream compression the smackx.jar file has to be present in the classpath. * * @return true if stream compression negotiation was successful. */ private boolean useCompression() { // If stream compression was offered by the server and we want to use // compression then send compression request to the server if (authenticated) { throw new IllegalStateException("Compression should be negotiated before authentication."); } try { Class.forName("com.jcraft.jzlib.ZOutputStream"); } catch (ClassNotFoundException e) { throw new IllegalStateException("Cannot use compression. Add smackx.jar to the classpath"); } if (hasAvailableCompressionMethod("zlib")) { requestStreamCompression(); // Wait until compression is being used or a timeout happened synchronized (this) { try { this.wait(SmackConfiguration.getPacketReplyTimeout() * 5); } catch (InterruptedException e) { // Ignore. } } return usingCompression; } return false; } /** * Request the server that we want to start using stream compression. When using TLS * then negotiation of stream compression can only happen after TLS was negotiated. If TLS * compression is being used the stream compression should not be used. */ private void requestStreamCompression() { try { writer.write("<compress xmlns='http://jabber.org/protocol/compress'>"); writer.write("<method>zlib</method></compress>"); writer.flush(); } catch (IOException e) { packetReader.notifyConnectionError(e); } } /** * Start using stream compression since the server has acknowledged stream compression. * * @throws Exception if there is an exception starting stream compression. */ void startStreamCompression() throws Exception { // Secure the plain connection usingCompression = true; // Initialize the reader and writer with the new secured version initReaderAndWriter(); // Set the new writer to use packetWriter.setWriter(writer); // Send a new opening stream to the server packetWriter.openStream(); // Notify that compression is being used synchronized (this) { this.notify(); } } /** * Notifies the XMPP connection that stream compression was denied so that * the connection process can proceed. */ void streamCompressionDenied() { synchronized (this) { this.notify(); } } /** * Establishes a connection to the XMPP server and performs an automatic login * only if the previous connection state was logged (authenticated). It basically * creates and maintains a socket connection to the server.<p> * <p/> * Listeners will be preserved from a previous connection if the reconnection * occurs after an abrupt termination. * * @throws org.jivesoftware.smack.XMPPException if an error occurs while trying to establish the connection. * Two possible errors can occur which will be wrapped by an XMPPException -- * UnknownHostException (XMPP error code 504), and IOException (XMPP error code * 502). The error codes and wrapped exceptions can be used to present more * appropiate error messages to end-users. */ public void connect() throws XMPPException { // Stablishes the connection, readers and writers connectUsingConfiguration(config); // Automatically makes the login if the user was previouslly connected successfully // to the server and the connection was terminated abruptly if (connected && wasAuthenticated) { // Make the login try { if (isAnonymous()) { // Make the anonymous login loginAnonymously(); } else { login(config.getUsername(), config.getPassword(), config.getResource()); } packetReader.notifyReconnection(); } catch (XMPPException e) { e.printStackTrace(); } } } /** * Sets whether the connection has already logged in the server. * * @param wasAuthenticated true if the connection has already been authenticated. */ private void setWasAuthenticated(boolean wasAuthenticated) { if (!this.wasAuthenticated) { this.wasAuthenticated = wasAuthenticated; } } @Override public void setRosterStorage(RosterStorage storage) throws IllegalStateException { if (roster != null) { throw new IllegalStateException("Roster is already initialized"); } this.rosterStorage = storage; } public void startKeepAliveThread(XmppManager xmppManager) throws Exception { packetWriter.startKeepAliveProcess(xmppManager); } }