服务器端：

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.net.ServerSocket;

import java.net.Socket;

public class SocketServer extends Thread{

public void run(){

Socket client;

String msg="";

try {

while(true){

client=responseSocket();

while(true){

msg=receiveMsg(client);

System.out.println("收到客户端消息："+msg);

sendMsg(client,msg);

if(true){

break;

}

}

closeSocket(client);

}

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

public static final int PORT=9999;

ServerSocket ss;

BufferedWriter bw;

BufferedReader br;

public void createSocket() throws IOException{

ss=new ServerSocket(PORT);

System.out.println("服务器已经开启······");

}

public Socket responseSocket() throws IOException{

Socket client=ss.accept();

System.out.println("客户端已经连接······");

return client;

}

public void closeSocket(Socket s) throws IOException{

br.close();

bw.close();

s.close();

System.out.println("客户端已经关闭······");

}

public void sendMsg(Socket s,String msg) throws IOException{

bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));

bw.write(msg+"\n");

bw.flush();

}

public String receiveMsg(Socket s) throws IOException{

br=new BufferedReader(new InputStreamReader(s.getInputStream()));

String msg=br.readLine();

System.out.println("服务器收到客户端消息："+msg);

return msg;

}

public SocketServer() throws IOException{

createSocket();

}

public static void main(String args[]) throws IOException{

SocketServer ss=new SocketServer();

if(ss!=null){

ss.start();

}

}

}

Android客户端：

package com.colorful.socket;

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.Bundle;

import android.view.View;

import android.view.View.OnClickListener;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class SocketClient extends Activity {

TextView tv;

EditText et;

Button btn;

/** Called when the activity is first created. */

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

init();

}

public void init(){

et=(EditText)findViewById(R.id.et);

btn=(Button)findViewById(R.id.btn);

tv=(TextView)findViewById(R.id.tv);

btn.setOnClickListener(new OnClickListener(){

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

String s=et.getText().toString();

try {

connectToServer(s);

} catch (UnknownHostException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

});

}

public void connectToServer(String s) throws UnknownHostException, IOException{

Socket client=requestSocket("输入电脑的IP地址",9999);

sendMsg(client,s);

String str=receiveMsg(client);

tv.setText(str);

System.out.println(str);

}

public Socket requestSocket(String host,int port) throws UnknownHostException, IOException{

Socket s=new Socket(host,port);

return s;

}

public void sendMsg(Socket socket,String msg) throws IOException{

BufferedWriter writer=new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));

writer.write((msg.replaceAll("\n", "")+"\n"));

writer.flush();

}

public String receiveMsg(Socket socket) throws IOException{

BufferedReader reader=new BufferedReader(new InputStreamReader(socket.getInputStream()));

String msg=reader.readLine();

return msg;

}

}

最后不要在AndroidManifest.xml中添加如下权限：