Android : server.accept do "app stopped working"

i am trying to do client/server but there is a problem in the server the code stop at "server.accept()" and stopped working this is the server code:

package com.example.do2do2messanger;

import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class Codes extends Activity {

private ServerSocket server;
private Socket connection;
private ObjectInputStream input;
private ObjectOutputStream output;
EditText sended;
TextView mirrored,chatwindow;
Button copied;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.gui);

    // text view of the messages
    mirrored = (TextView) findViewById(R.id.mirror_id);
    sended = (EditText) findViewById(R.id.send_id);
    copied = (Button) findViewById(R.id.copy_id);
    chatwindow = (TextView) findViewById(R.id.chat_id);


    try
    {
        server = new ServerSocket(4444);
        mirrored.setText("c1");
        waitforconnection();


    }
    catch(IOException e)
    {
        mirrored.setText("c2");
        e.printStackTrace();
    }

}

private void waitforconnection() throws IOException
{
    showmessage("waiting for someone to connect ... \n");
    connection = server.accept(); // acts as infinte loop for listening
    //showmessage("Now connected to " + connection.getInetAddress().getHostName());

}

The output: if i commented server.accept() it will give c1 then waiting for someone to connect as normal but if i leave it , it will stop the application and gives message: "unfortunately , app stopped working "