(a)Smack returns "service-unavailable (503)" error at login()

I'm trying to implement a simple jabber messenger on Android using asmack library. Here's the code:

public boolean login()
{
    if (connection != null && connection.isConnected())
    {
        Log.i("XMPP", connection.getHost());
        try 
        {
            connection.login(USERNAME, PASSWORD);
        } 
        catch (XMPPException e) 
        {
            e.printStackTrace();
            return false;
        }
        return true;
    }
    return false;
}

Exception I get after connection.login() (connection looks fine):

service-unavailable(503)
at org.jivesoftware.smack.NonSASLAuthentication.authenticate(NonSASLAuthentication.java:77)
at org.jivesoftware.smack.XMPPConnection.login(XMPPConnection.java:239)
at org.jivesoftware.smack.Connection.login(Connection.java:353)
at com.someapp.networking.XMPPMessenger.login(XMPPMessenger.java:60)
at com.someapp.XMPPService.onCreate(XMPPService.java:33)
at android.app.ActivityThread.handleCreateService(ActivityThread.java:2780)
at android.app.ActivityThread.access$3200(ActivityThread.java:119)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1917)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4363)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.Zyg开发者_开发百科oteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
at dalvik.system.NativeStart.main(Native Method)

What could be the mistake?

Asmack is able to establish a new connection to the server, but it falls into Non-SASL mode for some reason ( The call of NonSASLAuthentication.authenticate(NonSASLAuthentication.java:77) ). I think that's what the server is trying to tell you with the "service-unavailable(503)" response, is that it does not support Non-SASL authentication.

Try to debug why smack does not try SASL authentication.

Note: The lines in the smack source viewer are a bit off because off different versions and the patches from asmack.

It's working finally for me by this way :

ConnectionConfiguration connConfig = new ConnectionConfiguration(host,port,host);
connection = new XMPPConnection(connConfig);
connConfig.setSASLAuthenticationEnabled(true); 
connection.connect();
connection.login(userID, password);

I have used Android using Asmack library which I have downloaded from below URL:

https://code.google.com/p/asmack/downloads/detail?name=asmack-2010.05.07.jar

Be careful about the userID.

Instead of using

connection.login("username@ejabberdServerIP",password)

it's work for me only if I use connection.login("username",password);

Good luck...