Android TCP通信（一）

什么是Socket？

Socket是应用层与TCP/IP协议簇通讯的中间抽象层，Socket是一组接口，在设计模式中，Socket的设计就是门面模式，它把复杂的TCP/IP协议簇的内容隐藏在套接字接口后面，用户无需关心协议的实现，只需使用Socket提供的接口即可。

Socket的类型有两种，一种是面向连接的TCP应用服务，一种是面向无连接的UDP（User Data Package）应用服务。通俗的理解就是，TCP方式是打电话（连接性），UDP方式是发短信（无连接）。

Ok，以上是简单的科普，那么接下来就看下如何在Android上利用TCP/IP协议使用Socket与Server进行通讯吧！今天我们要使用的是面向连接的TCP方式。首先，在本机建立一个Java项目作为Server Client，代码如下

1.服务端

开启一个socket服务端监听一个端口。

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.ServerSocket;
import java.net.Socket;

public class SocketServerTest {

private static final int SERVER_PORT = 1234;

public static void main(String[] args) {

System.out.println("server begin lisening port " + SERVER_PORT
+ ".............");
try {
ServerSocket server = new ServerSocket(SERVER_PORT);
while (true) {
// 循环监听客户端请求
Socket clientSocket = server.accept();
System.out.println("server receiving.............");

try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream()));
// 从客户端监听到的信息
String str = reader.readLine();
System.out.println("server received= " + str);
} catch (Exception e) {
System.out.println("server error." + e.getMessage());
} finally {
clientSocket.close();
System.out.println("server close.");
}
}
} catch (IOException e) {
System.out.println("server error." + e.getMessage());
}
}
}

2.客户端

package com.lq.mypractice.activity;

import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;

import com.lq.mypractice.R;

import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.net.UnknownHostException;

public class SocketAndrodActivity extends AppCompatActivity {
/**
* Called when the activity is first created.
*/
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_socket_androd);

Button button = (Button) this.findViewById(R.id.button1);
button.setOnClickListener(new View.OnClickListener() {

@Override
public void onClick(View v) {
new SoketTask().execute();

}
});

}

private class SoketTask extends AsyncTask<Void, Integer, Integer> {
@Override
protected void onPreExecute() {
super.onPreExecute();
}

@Override
protected Integer doInBackground(Void... params) {
try {
System.out.println("Client：Connecting");
//IP地址和端口号（对应服务端），我这的IP是本地路由器的IP地址
Socket socket = new Socket("192.168.205.46", 1234);
//发送给服务端的消息
String message = "Message from Android phone";
try {
System.out.println("Client Sending: '" + message + "'");

//第二个参数为True则为自动flush
PrintWriter out = new PrintWriter(
new BufferedWriter(new OutputStreamWriter(
socket.getOutputStream())), true);
out.println(message);
//                      out.flush();
} catch (Exception e) {
e.printStackTrace();
} finally {
//关闭Socket
socket.close();
System.out.println("Client:Socket closed");
}
} catch (UnknownHostException e1) {
e1.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

@Override
protected void onProgressUpdate(Integer... values) {
super.onProgressUpdate(values);
}
}
}

3.测试

客户端：

05-30 11:28:46.302 18016-18802/com.lq.mypractice I/System.out: Client：Connecting
05-30 11:28:46.322 18016-18802/com.lq.mypractice I/System.out: Client Sending: 'Message from Android phone'
05-30 11:28:46.322 18016-18802/com.lq.mypractice I/System.out: Client:Socket closed

服务端：

server begin.............
server receiving.............
server received= Message from Android phone
server close.

参考链接

http://blog.csdn.net/ryantang03/article/details/8274517