android socket 编程实例

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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 plain copy

1. <?xml version="1.0" encoding="utf-8"?>  
2. <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    
3.     android:orientation="vertical"   
4.     android:layout_width="fill_parent"    
5.     android:layout_height="fill_parent">    
6.     <TextView   
7.         android:id="@+id/TextView"   
8.         android:singleLine="false"    
9.         android:layout_width="fill_parent"    
10.         android:layout_height="wrap_content" />    
11.     <EditText android:hint="content"   
12.         android:id="@+id/EditText01"    
13.         android:layout_width="fill_parent"    
14.         android:layout_height="wrap_content">    
15.     </EditText>    
16.     <Button   
17.         android:text="send"   
18.         android:id="@+id/Button02"    
19.         android:layout_width="fill_parent"    
20.         android:layout_height="wrap_content">    
21.     </Button>    
22. </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：

[java]  view plain copy

1. import java.io.BufferedReader;  
2. import java.io.BufferedWriter;  
3. import java.io.IOException;  
4. import java.io.InputStreamReader;  
5. import java.io.OutputStreamWriter;  
6. import java.io.PrintWriter;  
7. import java.net.ServerSocket;  
8. import java.net.Socket;  
9. import java.util.ArrayList;  
10. import java.util.List;  
11. import java.util.concurrent.ExecutorService;  
12. import java.util.concurrent.Executors;  
13.   
14.   
15. public class Main {  
16.     private static final int PORT = 9999;  
17.     private List<Socket> mList = new ArrayList<Socket>();  
18.     private ServerSocket server = null;  
19.     private ExecutorService mExecutorService = null; //thread pool  
20.       
21.     public static void main(String[] args) {  
22.         new Main();  
23.     }  
24.     public Main() {  
25.         try {  
26.             server = new ServerSocket(PORT);  
27.             mExecutorService = Executors.newCachedThreadPool();  //create a thread pool  
28.             System.out.print("server start ...");  
29.             Socket client = null;  
30.             while(true) {  
31.                 client = server.accept();  
32.                 mList.add(client);  
33.                 mExecutorService.execute(new Service(client)); //start a new thread to handle the connection  
34.             }  
35.         }catch (Exception e) {  
36.             e.printStackTrace();  
37.         }  
38.     }  
39.     class Service implements Runnable {  
40.             private Socket socket;  
41.             private BufferedReader in = null;  
42.             private String msg = "";  
43.               
44.             public Service(Socket socket) {  
45.                 this.socket = socket;  
46.                 try {  
47.                     in = new BufferedReader(new InputStreamReader(socket.getInputStream()));  
48.                     msg = "user" +this.socket.getInetAddress() + "come toal:"  
49.                         +mList.size();  
50.                     this.sendmsg();  
51.                 } catch (IOException e) {  
52.                     e.printStackTrace();  
53.                 }  
54.                   
55.             }  
56.   
57.             @Override  
58.             public void run() {  
59.                 // TODO Auto-generated method stub  
60.                 try {  
61.                     while(true) {  
62.                         if((msg = in.readLine())!= null) {  
63.                             if(msg.equals("exit")) {  
64.                                 System.out.println("ssssssss");  
65.                                 mList.remove(socket);  
66.                                 in.close();  
67.                                 msg = "user:" + socket.getInetAddress()  
68.                                     + "exit total:" + mList.size();  
69.                                 socket.close();  
70.                                 this.sendmsg();  
71.                                 break;  
72.                             } else {  
73.                                 msg = socket.getInetAddress() + ":" + msg;  
74.                                 this.sendmsg();  
75.                             }  
76.                         }  
77.                     }  
78.                 } catch (Exception e) {  
79.                     e.printStackTrace();  
80.                 }  
81.             }  
82.             
83.            public void sendmsg() {  
84.                System.out.println(msg);  
85.                int num =mList.size();  
86.                for (int index = 0; index < num; index ++) {  
87.                    Socket mSocket = mList.get(index);  
88.                    PrintWriter pout = null;  
89.                    try {  
90.                        pout = new PrintWriter(new BufferedWriter(  
91.                                new OutputStreamWriter(mSocket.getOutputStream())),true);  
92.                        pout.println(msg);  
93.                    }catch (IOException e) {  
94.                        e.printStackTrace();  
95.                    }  
96.                }  
97.            }  
98.         }      
99. }  

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