做出来大致就是这个界面。

服务器：

package hjc.testServer;
public class MyServerSocket {
    public static void main(String[] args) {
        new ServerListener().start();
   }
}
----------------------------------------------------------
package hjc.testServer;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.JOptionPane;
public class ServerListener extends Thread {
    public void run(){
        try {
            ServerSocket  serverSocket = new ServerSocket(12345);
            while(true){
            Socket socket=serverSocket.accept();
            JOptionPane.showMessageDialog(null, "有客户端链接到了");
            System.out.println("链接到了");
            ChartSocket cs=new ChartSocket(socket);
            cs.start();
            ChatManager.getChatManager().add(cs);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}
----------------------------------------------------------
package hjc.testServer;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.net.Socket;
public class ChartSocket extends Thread {
    Socket socket;
    BufferedWriter bw;  
    BufferedReader br; 
    public ChartSocket(Socket s) {  
        this.socket = s; 
        try {  
             bw = new BufferedWriter(new OutputStreamWriter(  
                    socket.getOutputStream(), "utf-8"));  
            br = new BufferedReader(new InputStreamReader(  
                    socket.getInputStream(), "utf-8"));  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  

    public void out(String out) {  
        try {  
            bw.write(out + "\n");// 必须要加换行符号,不然数据发不出去  
            bw.flush();  
        } catch (UnsupportedEncodingException e) {  
            e.printStackTrace();  
        } catch (IOException e) {  
            e.printStackTrace();  
        }  
    }  

    public void run(){
        try {
//          BufferedReader br=new BufferedReader(new InputStreamReader(socket.getInputStream(),"UTF-8"));
            String line=null;
            while((line=br.readLine())!=null){//reaadline是个阻塞函数  没有读取到会一直处于阻塞状态
                System.out.println("读取到了信息");
                System.out.println("客户端发来数据："+line);  
                ChatManager.getChatManager().publish(this, line);
                System.out.println("写入了信息");    
            }
            br.close();
        } catch (UnsupportedEncodingException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
    } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}
----------------------------------------------------------
package hjc.testServer;

import java.util.Vector;

public class ChatManager {

    /**
     * @param args
     */
    private ChatManager(){  }
    private static final ChatManager  cm=new ChatManager();
    public static ChatManager getChatManager(){
        return cm;
    }
    Vector<ChartSocket>  vector =new Vector<ChartSocket>();
    public void add(ChartSocket cs){
        vector.add(cs);
    }
    public void publish(ChartSocket cs,String out){
        for(int i=0;i<vector.size();i++){//遍历所有de chartsocket
            ChartSocket csChartSocket=vector.get(i);//获取循环中的第I个对象  telnet localhost 12345
            if(!cs.equals(csChartSocket)){//bushi 本身
                csChartSocket.out(out);
                System.out.println("将信息发送给所有客户 调用pulish:  "+out);

            }
        }
    }
}
==========================================================
客户端：

package com.example.androidclient;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.net.UnknownHostException;


import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity {

    EditText ip;
    EditText editText;
    TextView text;
    Button send, connect;

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        ip = (EditText) findViewById(R.id.ip);
        editText = (EditText) findViewById(R.id.edit);
        text = (TextView) findViewById(R.id.text);
        send = (Button) findViewById(R.id.send);
        connect = (Button) findViewById(R.id.connect);

        connect.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                connect();

            }
        });

        send.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                send();

            }
        });

    }

    // ----------------------------------------------
    Socket socket = null;
    BufferedReader reader = null;
    BufferedWriter writer = null;
    public void connect() {
AsyncTask<Void, String, Void> read = new AsyncTask<Void, String, Void>() {
            protected Void doInBackground(Void... params) {
    try {
    socket = new Socket("192.168.191.1", 12345);
    writer = new BufferedWriter(new OutputStreamWriter(
    socket.getOutputStream(),"utf-8"));
    Log.e("test", "writerwriterwriterwriter");

    reader = new BufferedReader(
                 new InputStreamReader(
                        socket.getInputStream(),"utf-8"));
            Log.e("test", "dream......................");
                    publishProgress("@Sucess");
                } catch (UnknownHostException e1) {
        Toast.makeText(MainActivity.this, "无法建立链接",
                            Toast.LENGTH_SHORT).show();
                     e1.printStackTrace();  
                } catch (IOException e1) {
       Toast.makeText(MainActivity.this, "无法建立链接",
                            Toast.LENGTH_SHORT).show();
                     e1.printStackTrace();  
                }
                try {
                    String line;
                    while ((line = reader.readLine()) != null) {
                        publishProgress(line);
                        Log.e("test", " readling()");
                    }   
                } catch (IOException e) {   
                    e.printStackTrace();
                }

                return null;
            }
            @Override
            protected void onProgressUpdate(String... values) {
                if (values[0].equals("@Sucess")) {
                    Toast.makeText(MainActivity.this, "建立链接",
                            Toast.LENGTH_SHORT).show();

                }else {
       Toast.makeText(MainActivity.this, "收到数据！",  
                            Toast.LENGTH_SHORT).show();  
                Log.e("test", "others");
                text.append("别人:" + values[0]+"\n");
                Log.e("test", "others");
                }
            }

        };
        read.execute();

    }

    public void send() {
        try {
            writer.write(editText.getText().toString() + "\n");
            writer.flush();
            text.append("我说 ： " + editText.getText().toString() + "\n");
            editText.setText("");
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}

登录那个跳转页和XML的编写比较简单，读者可自己写一个简单的页面。