android socket编程实例

android客户端通过socket与服务器进行通信可以分为以下几步：

应用程序与服务器通信可以采用两种模式：TCP可靠通信 和UDP不可靠通信。

（1）通过IP地址和端口实例化Socket，请求连接服务器：

socket = new Socket(HOST, PORT); //host:为服务器的IP地址 port：为服务器的端口号

（2）获取Socket流以进行读写，并把流包装进BufferWriter或者PrintWriter：

PrintWriter out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())),true);

这里涉及了三个类：socket.getOutputStream得到socket的输出字节流，OutputStreamWriter是字节流向字符流转换的桥梁，BufferWriter是字符流，然后再包装进PrintWriter。

（3）对Socket进行读写

if (socket.isConnected()) {

if (!socket.isOutputShutdown()) {

out.println(msg);

}

}

（4）关闭打开的流

out.close();

在写代码的过程中一定要注意对socket 输入流 输出流的关闭

下面是一个简单的例子：

main.xml

[html] view
plaincopyprint?

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:orientation="vertical"

android:layout_width="fill_parent"

android:layout_height="fill_parent">

<TextView

android:id="@+id/TextView"

android:singleLine="false"

android:layout_width="fill_parent"

android:layout_height="wrap_content" />

<EditText android:hint="content"

android:id="@+id/EditText01"

android:layout_width="fill_parent"

android:layout_height="wrap_content">

</EditText>

<Button

android:text="send"

android:id="@+id/Button02"

android:layout_width="fill_parent"

android:layout_height="wrap_content">

</Button>

</LinearLayout>

下面是android客户端的源代码：

[java] view
plaincopyprint?

package com.android.SocketDemo;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

import java.net.Socket;

import android.app.Activity;

import android.app.AlertDialog;

import android.content.DialogInterface;

import android.os.Bundle;

import android.os.Handler;

import android.os.Message;

import android.view.View;

import android.widget.Button;

import android.widget.EditText;

import android.widget.TextView;

public class SocketDemo extends Activity implements Runnable {

private TextView tv_msg = null;

private EditText ed_msg = null;

private Button btn_send = null;

// private Button btn_login = null;

private static final String HOST = "192.168.1.223";

private static final int PORT = 9999;

private Socket socket = null;

private BufferedReader in = null;

private PrintWriter out = null;

private String content = "";

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

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.main);

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

ed_msg = (EditText) findViewById(R.id.EditText01);

// btn_login = (Button) findViewById(R.id.Button01);

btn_send = (Button) findViewById(R.id.Button02);

try {

socket = new Socket(HOST, PORT);

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

out = new PrintWriter(new BufferedWriter(new OutputStreamWriter(

socket.getOutputStream())), true);

} catch (IOException ex) {

ex.printStackTrace();

ShowDialog("login exception" + ex.getMessage());

}

btn_send.setOnClickListener(new Button.OnClickListener() {

@Override

public void onClick(View v) {

// TODO Auto-generated method stub

String msg = ed_msg.getText().toString();

if (socket.isConnected()) {

if (!socket.isOutputShutdown()) {

out.println(msg);

}

}

}

});

new Thread(SocketDemo.this).start();

}

public void ShowDialog(String msg) {

new AlertDialog.Builder(this).setTitle("notification").setMessage(msg)

.setPositiveButton("ok", new DialogInterface.OnClickListener() {

@Override

public void onClick(DialogInterface dialog, int which) {

// TODO Auto-generated method stub

}

}).show();

}

public void run() {

try {

while (true) {

if (socket.isConnected()) {

if (!socket.isInputShutdown()) {

if ((content = in.readLine()) != null) {

content += "\n";

mHandler.sendMessage(mHandler.obtainMessage());

} else {

}

}

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

public Handler mHandler = new Handler() {

public void handleMessage(Message msg) {

super.handleMessage(msg);

tv_msg.setText(tv_msg.getText().toString() + content);

}

};

}

下面是服务器端得java代码：

[java] view
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import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.OutputStreamWriter;

import java.io.PrintWriter;

import java.net.ServerSocket;

import java.net.Socket;

import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

public class Main {

private static final int PORT = 9999;

private List<Socket> mList = new ArrayList<Socket>();

private ServerSocket server = null;

private ExecutorService mExecutorService = null; //thread pool

public static void main(String[] args) {

new Main();

}

public Main() {

try {

server = new ServerSocket(PORT);

mExecutorService = Executors.newCachedThreadPool(); //create a thread pool

System.out.print("server start ...");

Socket client = null;

while(true) {

client = server.accept();

mList.add(client);

mExecutorService.execute(new Service(client)); //start a new thread to handle the connection

}

}catch (Exception e) {

e.printStackTrace();

}

}

class Service implements Runnable {

private Socket socket;

private BufferedReader in = null;

private String msg = "";

public Service(Socket socket) {

this.socket = socket;

try {

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

msg = "user" +this.socket.getInetAddress() + "come toal:"

+mList.size();

this.sendmsg();

} catch (IOException e) {

e.printStackTrace();

}

}

@Override

public void run() {

// TODO Auto-generated method stub

try {

while(true) {

if((msg = in.readLine())!= null) {

if(msg.equals("exit")) {

System.out.println("ssssssss");

mList.remove(socket);

in.close();

msg = "user:" + socket.getInetAddress()

+ "exit total:" + mList.size();

socket.close();

this.sendmsg();

break;

} else {

msg = socket.getInetAddress() + ":" + msg;

this.sendmsg();

}

}

}

} catch (Exception e) {

e.printStackTrace();

}

}

public void sendmsg() {

System.out.println(msg);

int num =mList.size();

for (int index = 0; index < num; index ++) {

Socket mSocket = mList.get(index);

PrintWriter pout = null;

try {

pout = new PrintWriter(new BufferedWriter(

new OutputStreamWriter(mSocket.getOutputStream())),true);

pout.println(msg);

}catch (IOException e) {

e.printStackTrace();

}

}

}

}

}

注意在AndroidManifest.xml中加入对网络的访问权限

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

在写代码的过程中一定要注意对套接字和输入/输出流的关闭