java访问ejabber失败，求解,该如何解决

java访问ejabber失败，求解
package com.xmpp.util;

import org.jivesoftware.smack.Chat;
import org.jivesoftware.smack.MessageListener;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.packet.Message;

public class Test {
public Test(){
try{
// Create a connection to the igniterealtime.org XMPP server.
XMPPConnection con = new XMPPConnection("test.com");
// Connect to the server
con.connect();
// Most servers require you to login before performing other tasks.
con.login("ejabberd", "123");
// Start a new conversation with John Doe and send him a message.
// Disconnect from the server
con.disconnect();


}catch (XMPPException e){
System.out.println(e);
}
}
public static void main(String args[]){
Test t = new Test();
System.out.println("test");
}
}


控制台报错信息：

Exception in thread "main" java.lang.IllegalStateException: Not connected to server.
at org.jivesoftware.smack.XMPPConnection.sendPacket(XMPPConnection.java:445)
at org.jivesoftware.smack.NonSASLAuthentication.authenticate(NonSASLAuthentication.java:69)
at org.jivesoftware.smack.XMPPConnection.login(XMPPConnection.java:212)
at com.xmpp.util.Test.<init>(Test.java:17)
at com.xmpp.util.Test.main(Test.java:36)


通过浏览器登录控制台没问题。
ejabberd@test
123

------解决方案--------------------
求解啊 。我也遇到了同样的问题。不过是在android
上面。。。。顶起！
------解决方案--------------------
？？？我用你的程序登录没有报错啊...
------解决方案--------------------
同问 不知道楼主解决了没