通过代理连接到Facebook服务器时出错

Question

我在从代理后面连接到gtalk/facebook服务器时遇到问题。在doPost下的我的loginservlet中，我在与服务器建立连接之前指定代理设置。代码如下：

package web; 

import java.io.IOException; 
import java.io.PrintWriter; 

    import javax.servlet.ServletException; 
    import javax.servlet.http.HttpServlet; 
    import javax.servlet.http.HttpServletRequest; 
    import javax.servlet.http.HttpServletResponse; 

    import org.jivesoftware.smack.ConnectionConfiguration; 
    import org.jivesoftware.smack.SASLAuthentication; 
    import org.jivesoftware.smack.XMPPConnection; 
    import org.jivesoftware.smack.XMPPException; 
    import org.jivesoftware.smack.proxy.ProxyInfo; 

    import dao.MySASLDigestMD5Mechanism; 

    public class LoginFacebookServlet extends HttpServlet { 
private static final long serialVersionUID = 1L; 

    public LoginFacebookServlet() { 
    super(); 

    } 
XMPPConnection connection; 
/** 
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 
*/ 
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
    String userName = request.getParameter("usrnm_fb"); 
    String password = request.getParameter("password_fb"); 

    response.setContentType("text/html"); 
    PrintWriter pw=response.getWriter(); 

    SASLAuthentication.registerSASLMechanism("DIGEST-MD5", MySASLDigestMD5Mechanism.class); 
    //SASLAuthentication.supportSASLMechanism("DIGEST-MD5", 0); 

    ProxyInfo proxyInfo = new ProxyInfo(ProxyInfo.ProxyType.HTTP,"proxy.xxx.com" "talk.google.com", port, "username", "password"); 
    ConnectionConfiguration config = new ConnectionConfiguration("chat.facebook.com",5222,proxyInfo); 
    connection = new XMPPConnection(config); 
    config.setSASLAuthenticationEnabled(true); 
    try { 
     connection.connect(); 
    } catch (XMPPException e) { 
     e.printStackTrace(); 
    } 
    try { 
     connection.login(userName, password); 
    } catch (XMPPException e) { 
     e.printStackTrace(); 
    } 
    System.out.println(connection.isAuthenticated()); 
    // System.out.println("Welcome!!you are now connected to facebook"); 
} 

}

当我运行应用程序它仍然给我500状态error.Following是堆栈跟踪

XMPPError connecting to chat.facebook.com:5222.: remote-server-error(502) XMPPError  connecting to chat.facebook.com:5222. 
    -- caused by: java.net.ConnectException: Connection timed out: connect 
at org.jivesoftware.smack.XMPPConnection.connectUsingConfiguration(XMPPConnection.java:900) 
at org.jivesoftware.smack.XMPPConnection.connect(XMPPConnection.java:1415) 
at web.LoginFacebookServlet.doPost(LoginFacebookServlet.java:52) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) 
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) 
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) 
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) 
at java.lang.Thread.run(Thread.java:619) 
Nested Exception: 
java.net.ConnectException: Connection timed out: connect 
at java.net.PlainSocketImpl.socketConnect(Native Method) 
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333) 
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195) 
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182) 
at java.net.Socket.connect(Socket.java:529) 
at java.net.Socket.connect(Socket.java:478) 
at    org.jivesoftware.smack.proxy.DirectSocketFactory.createSocket(DirectSocketFactory.java:28) 
at org.jivesoftware.smack.XMPPConnection.connectUsingConfiguration(XMPPConnection.java:888) 
at org.jivesoftware.smack.XMPPConnection.connect(XMPPConnection.java:1415) 
at web.LoginFacebookServlet.doPost(LoginFacebookServlet.java:52) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
at  org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) 
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) 
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) 
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) 
at java.lang.Thread.run(Thread.java:619) 
Apr 26, 2011 11:32:24 AM org.apache.catalina.core.StandardWrapperValve invoke 
SEVERE: Servlet.service() for servlet LoginFacebookServlet threw exception 
java.lang.IllegalStateException: Not connected to server. 
at org.jivesoftware.smack.XMPPConnection.login(XMPPConnection.java:382) 
at org.jivesoftware.smack.XMPPConnection.login(XMPPConnection.java:349) 
at web.LoginFacebookServlet.doPost(LoginFacebookServlet.java:57) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637) 
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290) 
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) 
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233) 
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191) 
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) 
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) 
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) 
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:298) 
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:852) 
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:588) 
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489) 
at java.lang.Thread.run(Thread.java:619) 

我检查编辑看看是否有更多的东西通过传递代理添加，但我无法理解我的错在哪里？

谢谢:)