android局域网udp广播demo

package com.test; import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import java.net.NetworkInterface; import java.net.SocketException; import java.net.UnknownHostException; import java.util.Enumeration; import android.content.Context; import android.net.wifi.WifiManager; import android.os.Handler; import android.os.Message; import android.util.Log; import android.widget.Toast; public class MulticastServer implements Runnable{ private InetAddress mBroadcastAddr; private DatagramSocket mSocket; private DatagramPacket mDatagram; private byte[] mBuffer = null; public static final int SERVER_SEND_PORT = 4445; public static final int CLIENT_RECEIVE_PORT = 4446; //Seehttp://www.gznc.edu.cn/yxsz/jjglxy/book/Java_api/java/net/MulticastSocket.html public static final String BROADCAST_IP = "234.5.6.7"; private Thread mThread = null; private static final String TAG = "MulticastServer"; private Context mContext = null; public MulticastServer(Context context){ Log.d(TAG, "######## MulticastServer ##########"); mContext = context; // WifiManager wifiManager = (WifiManager)context.getSystemService(Context.WIFI_SERVICE); // WifiManager.MulticastLock multicastLock = wifiManager.createMulticastLock("mydebuginfo"); // multicastLock.acquire(); try { mSocket = new DatagramSocket(SERVER_SEND_PORT); } catch (SocketException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } try { mBroadcastAddr=InetAddress.getByName(BROADCAST_IP); } catch (UnknownHostException e) { // TODO Auto-generated catch block e.printStackTrace(); } Log.d(TAG, "MulticastServer"); mBuffer = getLocalIpAddress().getBytes(); String str = new String(mBuffer); Log.d(TAG, "mBuffer = " + str); mDatagram = new DatagramPacket(mBuffer, mBuffer.length, mBroadcastAddr, CLIENT_RECEIVE_PORT); mThread = new Thread(this); } public void startSend() { Log.d(TAG, "startSend"); SEND_FLAG = true; mThread.start(); } public void stopSend() { SEND_FLAG = false; } private boolean SEND_FLAG = true; @Override public void run() { // TODO Auto-generated method stub while(SEND_FLAG) { broadcast_data(); } } private String sendStr = ""; private void broadcast_data() { try { Log.d(TAG, "broadcast_data"); mSocket.send(mDatagram); sendStr = new String(mDatagram.getData()); Log.d(TAG, "send ok data = " + sendStr); mHandler.sendEmptyMessage(TOAST_MSG_SEND); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } try { Thread.sleep(200); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } } public String getLocalIpAddress() { try { for (Enumeration<NetworkInterface> en = NetworkInterface .getNetworkInterfaces(); en.hasMoreElements();) { NetworkInterface intf = en.nextElement(); for (Enumeration<InetAddress> enumIpAddr = intf .getInetAddresses(); enumIpAddr.hasMoreElements();) { InetAddress inetAddress = enumIpAddr.nextElement(); if (!inetAddress.isLoopbackAddress()) { return inetAddress.getHostAddress().toString(); } } } } catch (SocketException ex) { Log.e("WifiPreference IpAddress", ex.toString()); } return ""; } private final int TOAST_MSG_SEND = 0x01; private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch(msg.what) { case TOAST_MSG_SEND: Toast.makeText(mContext, sendStr, Toast.LENGTH_SHORT).show(); } } }; }