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

<?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：

package com.example.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.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Build;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.StrictMode;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

@TargetApi(Build.VERSION_CODES.GINGERBREAD)
@SuppressLint("NewApi")
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. */
    @TargetApi(Build.VERSION_CODES.GINGERBREAD)
    @SuppressLint("NewApi")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_socket_demo);
        ////Android 2.3及以上调用严苛模式
        if (android.os.Build.VERSION.SDK_INT > 9) {
            StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                    .permitAll().build();
            StrictMode.setThreadPolicy(policy);
        }
        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() {

            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() {

                    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);
        }
    };
}

下面是服务器端的java代码：

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

转载来源