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：
<uses-permission android:name="android.permission.INTERNET"/>