android广播 组播,【Android】一个通过组播实现的局域网服务器搜索功能
服务器端代码：
package com.isunhui.multicast;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;
public class Main {
public static void main(String[] args){
try{
MulticastSocket ms = new MulticastSocket(10000);//生成套接字并绑定端口
InetAddress group = InetAddress.getByName("224.0.0.1");//设定多播IP
ms.setNetworkInterface(NetworkInterface.getByInetAddress(group.getLocalHost()));
ms.joinGroup(group);//接受者加入多播组，需要和发送者在同一组
byte[] buf = new byte[100];
DatagramPacket packet = new DatagramPacket(buf , buf.length);//创建接收报文，以接收通过广播传递过来的
while(true){
ms.receive(packet);//接收报文，程序停滞等待直到接收到报文
System.out.println("receive:"+new String(packet.getData()));
System.out.println("from "+packet.getAddress().getHostAddress());
DatagramSocket ds = new DatagramSocket();
byte[] buf2 = "server address".getBytes("utf-8");
DatagramPacket packet2=new DatagramPacket(buf2,buf2.length,packet.getAddress(),10001);
ds.send(packet2);//发送报文
ds.close();
}
}catch(Exception e){
System.out.println(e.toString());
}
}
}
手机端代码：
package com.isunhui.multicast;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;
import java.util.ArrayList;
import java.util.Enumeration;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class MainActivity extends ActionBarActivity {
private Button send;
private TextView serverIP;
private TextView localIP;
private ArrayList ipList;
private Handler handler;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
serverIP = (TextView)findViewById(R.id.serverIP);
localIP = (TextView)findViewById(R.id.localIP);
send = (Button)findViewById(R.id.send);
ipList = new ArrayList();
handler = new Handler();
try
{
for (Enumeration en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();)
{
NetworkInterface intf = en.nextElement();
for (Enumeration enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();)
{
InetAddress inetAddress = enumIpAddr.nextElement();
if (!inetAddress.isLoopbackAddress())
{
ipList.add(inetAddress);
}
}
}
}
catch (Exception e)
{
Log.e("getIP", e.toString());
}
localIP.setText("本地IP："+ipList.get(1).getHostAddress().toString());
final Runnable runnable = new Runnable() {
@Override
public void run() {
try{
MulticastSocket msSocket = new MulticastSocket();//生成套接字并绑定30001端口
InetAddress group=InetAddress.getByName("224.0.0.1");//设定多播IP
byte[] buff = "search server".getBytes("utf-8");//设定多播报文的数据
msSocket.joinGroup(group);//加入多播组，发送方和接受方处于同一组时，接收方可抓取多播报文信息
msSocket.setTimeToLive(4);//设定TTL
//设定UDP报文(内容，内容长度，多播组，端口)
DatagramPacket packet = new DatagramPacket(buff,buff.length,group,10000);
msSocket.send(packet);//发送报文
msSocket.close();//关闭套接字
DatagramSocket ds = new DatagramSocket(10001);
byte[] buf2 = new byte[100];
DatagramPacket packet2 = new DatagramPacket(buf2,buf2.length);
ds.receive(packet2);
ds.close();
final String serverIP_str=packet2.getAddress().getHostAddress();
handler.post(new Runnable(){
@Override
public void run() {
// TODO Auto-generated method stub
serverIP.setText("服务器IP："+serverIP_str);
}
});
}catch (Exception e){
Log.e("sendMulticast",e.toString());
}
}
};
send.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
new Thread(runnable).start();
}
});
}
@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 boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}