android UDP通信

转自：http://blog.csdn.net/yearafteryear/article/details/9271763

 源代码：

MainActivity.java

 package com.example.udp;

 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetAddress;

 import android.os.Bundle;
 import android.os.Message;
 import android.app.Activity;
 import android.view.Menu;
 import android.view.View;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
 import android.os.Handler;

 public class MainActivity extends Activity implements
         android.view.View.OnClickListener {
     public static final String SERVERIP = "127.0.0.1";
     public static final int SERVERPORT = 4444;
     public TextView text1;
     public EditText input;
     public Button btn;
     public boolean start;
     public Handler Handler;

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_main);
         text1 = (TextView) findViewById(R.id.textView1);
         input = (EditText) findViewById(R.id.editText1);
         btn = (Button) findViewById(R.id.button1);
         btn.setOnClickListener(this);
         start = false;
         new Thread(new Server()).start();
         try {
             Thread.sleep(500);
         } catch (InterruptedException e) {

         }
         new Thread(new Client()).start();
         Handler = new Handler() {
             @Override
             public void handleMessage(Message msg) {
                 String text = (String) msg.obj;
                 text1.append(text);
             }
         };
     }

     public class Client implements Runnable {
         @Override
         public void run() {
             while (start == false) {
             }
             try {
                 Thread.sleep(500);
             } catch (InterruptedException e1) {
                 // TODO Auto-generated catch block
                 e1.printStackTrace();
             }
             try {
                 InetAddress serverAddr = InetAddress.getByName(SERVERIP);
                 updatetrack("Client: Start connecting\n");
                 DatagramSocket socket = new DatagramSocket();
                 byte[] buf;
                 if (!input.getText().toString().isEmpty()) {
                     buf = input.getText().toString().getBytes();
                 } else {
                     buf = ("Default message").getBytes();
                 }
                 DatagramPacket packet = new DatagramPacket(buf, buf.length,
                         serverAddr, SERVERPORT);
                 updatetrack("Client: Sending ‘" + new String(buf) + "’\n");
                 socket.send(packet);
                 updatetrack("Client: Message sent\n");
                 updatetrack("Client: Succeed!\n");
             } catch (Exception e) {
                 updatetrack("Client: Error!\n");
             }
         }
     }

     public class Server implements Runnable {
         @Override
         public void run() {
             while (start == false) {
             }
             try {
                 InetAddress serverAddr = InetAddress.getByName(SERVERIP);
                 updatetrack("\nServer: Start connecting\n");
                 DatagramSocket socket = new DatagramSocket(SERVERPORT,
                         serverAddr);
                 byte[] buf = new byte[17];
                 DatagramPacket packet = new DatagramPacket(buf, buf.length);
                 updatetrack("Server: Receiving\n");
                 socket.receive(packet);
                 updatetrack("Server: Message received: ‘"
                         + new String(packet.getData()) + "’\n");
                 updatetrack("Server: Succeed!\n");
             } catch (Exception e) {
                 updatetrack("Server: Error!\n");
             }
         }
     }

     public void updatetrack(String s) {
         Message msg = new Message();
         String textTochange = s;
         msg.obj = textTochange;
         Handler.sendMessage(msg);
     }

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         // Inflate the menu; this adds items to the action bar if it is present.
         getMenuInflater().inflate(R.menu.main, menu);
         return true;
     }

     @Override
     public void onClick(View v) {
         // TODO Auto-generated method stub
         if(v.getId()==R.id.button1)
             start = true;
     }
 }

activity_main.xml

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
     android:orientation="vertical" >

 <EditText
     android:id="@+id/editText1"
     android:layout_width="match_parent"
     android:layout_height="wrap_content" >
     <requestFocus />
 </EditText>

 <Button
     android:id="@+id/button1"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:text="Send" />

 <TextView
     android:id="@+id/textView1"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:text="Communication History:"
     android:textAppearance="?android:attr/textAppearanceLarge" />

 </LinearLayout>

AndroidManifest.xml

 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="com.example.udp"
     android:versionCode="1"
     android:versionName="1.0" >

     <uses-sdk
         android:minSdkVersion="8"
         android:targetSdkVersion="16" />

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

     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/AppTheme" >
         <activity
             android:name="com.example.udp.MainActivity"
             android:label="@string/app_name" >
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />

                 <category android:name="android.intent.category.LAUNCHER" />
             </intent-filter>
         </activity>
     </application>

 </manifest>