Android Datagram Sockets not working -

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i trying implement basic datagram sockets in android. starting 1 of samples available on web:

string messagestr="hello android!"; int server_port = 54372; try {   datagramsocket s = new datagramsocket();   inetaddress local = null;   local = inetaddress.getbyname("192.168.100.127");   int msg_length=messagestr.length();   byte[] message = messagestr.getbytes();   datagrampacket p = new datagrampacket(message, msg_length, local, server_port);   s.send(p); } catch (socketexception e) {   e.printstacktrace(); } catch (unknownhostexception e) {   e.printstacktrace(); } catch (ioexception e) {   e.printstacktrace(); }

i have enables internet permissions in androidmanifest.xml:

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

the program dies when hits s.send(p) command.

what missing? must obvious.

you getting error not catch-ing: networkonmainthreadexception. should networking staff in thread or asynctask.

for example:

class mythread extends thread {     @override     public void run()     {         udpsend();     }      void udpsend()     {         string messagestr = "hello android!";         int server_port = 54372;         try         {             datagramsocket s = new datagramsocket();             inetaddress local = null;             local = inetaddress.getbyname("192.168.1.57");             int msg_length = messagestr.length();             byte[] message = messagestr.getbytes();             datagrampacket p = new datagrampacket(message, msg_length, local, server_port);             s.send(p);             android.util.log.w("udp", "works fine!");         }         catch (socketexception e)         {             e.printstacktrace();         }         catch (unknownhostexception e)         {             e.printstacktrace();         }         catch (ioexception e)         {             e.printstacktrace();         }         catch (exception e)         {             android.util.log.w("udp", "catched here.");             e.printstacktrace();         }     }  }

to execute thread in main thread: new mythread().start();

update:

udp receiver in asynctask: real example of app. i've removed lines not relevant. show doinbackgroud, 1 receive udp packets.

@override protected void doinbackground(void... urls) {     datagramsocket socketudp;      try     {         socketudp = new datagramsocket(5050);         socketudp.setsotimeout(5000);          // set true if want receive broadcast packets         socketudp.setbroadcast(false);      }     catch (exception e)     {         e.printstacktrace();         return null;     }      byte[] buff = new byte[512];     datagrampacket packet = new datagrampacket(buff, buff.length);     try     {         asynctask_udp_is_running=true;         // keep running until application gets inactive         while (aplicationactive)         {             try             {                 socketudp.receive(packet);                 android.util.log.w("udp", "got packet");             }             catch (java.net.sockettimeoutexception ex)             {                 // timeout             }             catch (exception e)             {                 e.printstacktrace();                 return null;              }         }     }         {         asynctask_udp_is_running=false;     }     return null; }

}


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