android socket編程執行個體

android用戶端通過socket與伺服器進行通訊可以分為以下幾步：

應用程式與伺服器通訊可以採用兩種模式：TCP可靠通訊 和UDP不可靠通訊。

（1）通過IP地址和連接埠執行個體化Socket，請求串連伺服器：

     socket = new Socket(HOST, PORT);   //host:為伺服器的IP地址  port：為伺服器的連接埠號碼

（2）擷取Socket流以進行讀寫，並把流封裝進BufferWriter或者PrintWriter：

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

   這裡涉及了三個類：socket.getOutputStream得到socket的輸出位元組流，OutputStreamWriter是位元組流向字元流轉換的橋樑，BufferWriter是字元流，然後再封裝進PrintWriter。

（3）對Socket進行讀寫

     if (socket.isConnected()) {
                    if (!socket.isOutputShutdown()) {
                        out.println(msg);
                    }
                }

（4）關閉開啟的流

      out.close();

 在寫代碼的過程中一定要注意對socket  輸入資料流  輸出資料流的關閉

 

下面是一個簡單的例子：

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用戶端的原始碼：

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);        }    };}

下面是伺服器端得java代碼：

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中加入對網路的存取權限

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

 

在寫代碼的過程中一定要注意對通訊端和輸入/輸出流的關閉