新建两个Android项目：（例如SocketServer和SocketClient）

简单起见，Server端只发送一条信息，Client端只接收信息。

Server端代码：

public class MainActivity extends Activity {@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);new Thread(new Runnable() {@Overridepublic void run() {try {ServerSocket serverSocket = new ServerSocket(12333);while (true) {Socket socket = serverSocket.accept();BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));writer.write("Test Socket\r\n");writer.flush();}} catch (IOException e) {e.printStackTrace();}}}).start();}}

启动SocketServer，然后进adb shell,用netstat -tln查看端口占用情况，可以看到服务端已经成功运行：

client端代码：

public class MainActivity extends Activity {private TextView tv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);tv = (TextView) findViewById(R.id.text_view);new Thread(new Runnable() {@Overridepublic void run() {try {Socket socket = new Socket(InetAddress.getLocalHost(),12333);BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));String line;while ((line = reader.readLine()) != null) {Log.i("socket client", line);tv.setText(line);}} catch (UnknownHostException e) {e.printStackTrace();} catch (IOException e) {e.printStackTrace();}}}).start();}
}

启动SocketClient，因为是本地连接，所以用InetAddress.getLocalHost()来获取本地服务地址。

这时候我们可以看到输出的Log信息，以及TextView上显示了我们接收到的信息！

注意点：

1.Server和Client的端口号要一致，且不能和其它端口冲突！

2.只要调用了reader.close() 或 writer.close()则建立起来的Socket通信将被关闭！