Android UDP broadcast Packet crawl

Just paste the code, the previous write suddenly forget.

Private Wifimanager.multicastlock Multicastlock; public void init (context context) {Wifimanager Wifimanager = (wifimanager) context.getsystemservice (context.wifi_s         Ervice);    Multicastlock = Wifimanager.createmulticastlock ("my_net");            } public byte[] Fetchdata () {try {multicastlock.acquire ();            MulticastSocket multicastsocket = new MulticastSocket (55551);            InetAddress Group = inetaddress.getbyname ("224.0.0.2");            Multicastsocket.setsotimeout (3000);            Multicastsocket.joingroup (group);            Multicastsocket.setloopbackmode (TRUE);            byte[] buffer = new BYTE[512];            Datagrampacket packet = new Datagrampacket (buffer, buffer.length);            Multicastsocket.receive (packet);        return buffer;        } catch (Exception e) {e.printstacktrace ();    } finally {multicastlock.release ();//Must be released} return null; }

Permission to join

    <uses-permission android:name= "Android.permission.INTERNET"/>    <uses-permission android:name= " Android.permission.ACCESS_NETWORK_STATE "/>    <uses-permission android:name=" android.permission.ACCESS_ Wifi_state "/>    <uses-permission android:name=" Android.permission.CHANGE_WIFI_MULTICAST_STATE "/>    <uses-permission android:name= "Android.permission.CHANGE_WIFI_STATE"/>    <uses-permission Android:name= "Android.permission.CHANGE_NETWORK_STATE"/>    <uses-permission android:name= " Android.permission.CHANGE_WIFI_MULTICAST_STATE "/>

Android UDP broadcast Packet crawl