Android 接收数据时出现多播套接字错误?
我是套接字编程新手。我正在使用多播套接字通过wifi热点网络进行广播。但我在接收端面临问题。 这是我的密码 服务器端Android 接收数据时出现多播套接字错误?,android,network-programming,udp,broadcast,multicastsocket,Android,Network Programming,Udp,Broadcast,Multicastsocket,我是套接字编程新手。我正在使用多播套接字通过wifi热点网络进行广播。但我在接收端面临问题。 这是我的密码 服务器端 import java.io.IOException; import java.net.DatagramPacket; import java.net.DatagramSocket; import java.net.InetAddress; import android.app.Service; import android.content.Intent; import andr
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;
public class SenderService extends Service
{
SenderThread currentSender;
public class SenderThread extends Thread
{
public void run()
{
Log.d("in thread","in service");
try
{
InetAddress group = InetAddress.getByName("224.0.0.3");
int port=10000;
DatagramSocket sock=new DatagramSocket();
sock.setBroadcast(true);
String msg="hello";
byte []b3=new byte[1024];
DatagramPacket packet;
b3=msg.getBytes();
while (true)
{
try
{
packet = new DatagramPacket(b3, b3.length,group, port);
sock.send(packet);
Log.d("MSG:", "sent");
} catch (IOException e)
{
Log.d("Send Excp:", e+"");
// TODO Auto-generated catch block
e.printStackTrace();
}
finally
{
sock.close();
}
}
} catch (Exception e)
{
e.printStackTrace();
}
}
}
@Override
public void onCreate() {
// TODO Auto-generated method stub
super.onCreate();
}
@Override
public IBinder onBind(Intent arg0)
{
// TODO Auto-generated method stub
return null;
}
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
new SenderThread().start();
return Service.START_STICKY;
}
}
客户端代码
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.MulticastSocket;
import java.net.NetworkInterface;
import java.util.Enumeration;
import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.net.wifi.WifiManager;
import android.net.wifi.WifiManager.MulticastLock;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
public class ReceiverActivity extends Activity
{
Button b;
Handler h;
class MyRTh extends Thread
{
InetAddress group=null ;
WifiManager wifi = (WifiManager)getSystemService(Context.WIFI_SERVICE);
MulticastLock lock = wifi.createMulticastLock("HelloAndroid");
public void run()
{
try
{
lock.acquire();
}
catch (Exception e) {
// TODO: handle exception
Log.d("lock",e+"");
}
try
{
final MulticastSocket sock=new MulticastSocket(10000);
group= InetAddress.getByName("224.0.0.3");
//sock.setSoTimeout(15000);
try
{
sock.joinGroup(group);
}
catch(Exception e)
{
Log.d("join",""+e.toString());
}
while(true)
{
try
{
Log.d("in try","l4");
byte[] data = new byte[1024];
// TODO Auto-generated method stub
DatagramPacket packet = new DatagramPacket(data, data.length);
Log.d("in run","l4");
try {
sock.receive(packet);
String s = new String(packet.getData());
Log.e("MSG:", "Received");
Log.d("msg",s);
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
Log.d("err",e.toString());
}
}
catch (Exception e)
{
Log.d("Excp", e.toString()+"");
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}catch (Exception e) {
// TODO: handle exception
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_receiver);
Toast.makeText(getApplicationContext(), "Receiving", Toast.LENGTH_SHORT).show();
Log.d("1","l1");
b=(Button)findViewById(R.id.buttonr);
b.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0)
{
MyRTh th=new MyRTh();
th.start();
}
});
}
}
我的问题是客户端代码在进入socket.receive()方法时被卡住了。我从两边开始移动数据。已在服务器端启动热点并从客户端连接到它。尝试将此启用套接字设置为可启用。setBroadcast(true) 我的问题是我的客户端代码在转到socket.receive()方法时卡住了 它会阻塞 问题就在这里。224.0.0.0至224.0.0.255范围内的多播地址保留用于低级多播支持操作。使用范围为224.0.1.0至239.255.255.255的地址,但也请参见RFC 2365
sock.setBroadcast(true);
不必要。去除你不是在广播,你是在多播
byte []b3=new byte[1024];
DatagramPacket packet;
b3=msg.getBytes();
两行以后重新分配时,不需要初始化b3
finally
{
sock.close();
}
您正在关闭while(true)
循环内的套接字。因此,它将发送一个多播,然后以一个“套接字关闭”异常退出,您在这里没有报告这个异常。移除
String s = new String(packet.getData());
这应该是
新字符串(packet.getData(),packet.getOffset(),packet.getLength()
他们真的让你在工作的地方缩进代码这么差吗?他不是在广播,他是在多播。
finally
{
sock.close();
}
String s = new String(packet.getData());