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Smack/source/org/jivesoftware/smack/XMPPConnection.java

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/**
* $RCSfile$
* $Revision$
* $Date$
*
* 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 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 javax.net.ssl.KeyManager;
import javax.net.ssl.KeyManagerFactory;
import javax.net.ssl.SSLContext;
import javax.net.ssl.SSLSocket;
import javax.security.auth.callback.Callback;
import javax.security.auth.callback.CallbackHandler;
import javax.security.auth.callback.PasswordCallback;
import java.io.*;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;
import java.net.Socket;
import java.net.UnknownHostException;
import java.security.KeyStore;
import java.security.Provider;
import java.security.Security;
import java.util.Collection;
/**
* 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 Connection
* @author Matt Tucker
*/
public class XMPPConnection extends Connection {
/**
* The socket which is used for this connection.
*/
Socket socket;
String connectionID = null;
private String user = null;
private boolean connected = false;
// socketClosed is used concurrent
// by XMPPConnection, PacketReader, PacketWriter
private volatile boolean socketClosed = 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 connection in the same way {@link #XMPPConnection(String,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 connection in the same way {@link #XMPPConnection(ConnectionConfiguration,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;
}
@Override
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();
}
// Indicate that we're now authenticated.
authenticated = true;
anonymous = false;
// Create the roster if it is not a reconnection or roster already created by getRoster()
if (this.roster == null) {
this.roster = new Roster(this);
}
if (config.isRosterLoadedAtLogin()) {
this.roster.reload();
}
// Set presence to online.
if (config.isSendPresence()) {
packetWriter.sendPacket(new Presence(Presence.Type.available));
}
// Stores the authentication 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);
}
}
@Override
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();
}
// 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() {
// synchronize against login()
synchronized(this) {
// if connection is authenticated the roster is already set by login()
// or a previous call to getRoster()
if (!isAuthenticated() || isAnonymous()) {
if (roster == null) {
roster = new Roster(this);
}
return roster;
}
}
if (!config.isRosterLoadedAtLogin()) {
roster.reload();
}
// 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 isSocketClosed() {
return socketClosed;
}
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 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.
if (packetWriter != null) {
packetWriter.sendPacket(unavailablePresence);
}
this.setWasAuthenticated(authenticated);
authenticated = 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.
}
// Set socketClosed to true. This will cause the PacketReader
// and PacketWriter to ingore any Exceptions that are thrown
// because of a read/write from/to a closed stream.
// It is *important* that this is done before socket.close()!
socketClosed = true;
try {
socket.close();
} catch (Exception e) {
e.printStackTrace();
}
// In most cases the close() should be successful, so set
// connected to false here.
connected = false;
// Close down the readers and writers.
if (reader != null) {
try {
// Should already be closed by the previous
// socket.close(). But just in case do it explicitly.
reader.close();
}
catch (Throwable ignore) { /* ignore */ }
reader = null;
}
if (writer != null) {
try {
// Should already be closed by the previous
// socket.close(). But just in case do it explicitly.
writer.close();
}
catch (Throwable ignore) { /* ignore */ }
writer = null;
}
// Make sure that the socket is really closed
try {
// Does nothing if the socket is already closed
socket.close();
}
catch (Exception e) {
// Ignore.
}
saslAuthentication.init();
}
public synchronized void disconnect(Presence unavailablePresence) {
// 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 Connection#addPacketInterceptor(PacketInterceptor, 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 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(PacketListener, 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(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);
}
socketClosed = false;
initConnection();
}
/**
* Initializes the connection by creating a packet reader and writer and opening a
* XMPP stream to the server.
*
* @throws 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)
packetWriter.startKeepAliveProcess();
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().getHostAddress(), 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 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;
}
}
}