How to send msg using Socket between two android devices.? -

here code

@override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_server);     serverstatus = (textview) findviewbyid(r.id.server_status);      serverip = getlocalipaddress();      thread fst = new thread(new serverthread());     fst.start(); }  public class serverthread implements runnable {      public void run() {         try {             if (serverip != null) {                 handler.post(new runnable() {                     @override                     public void run() {                         serverstatus.settext("listening on ip: " + serverip);                     }                 });                 serversocket = new serversocket(serverport);                 while (true) {                     // listen incoming clients                     socket client = serversocket.accept();                     handler.post(new runnable() {                         @override                         public void run() {                             serverstatus.settext("connected.");                         }                     });                      try {                         bufferedreader in = new bufferedreader(new inputstreamreader(client.getinputstream()));                         string line = null;                         while ((line = in.readline()) != null) {                             log.d("serveractivity", line);                             handler.post(new runnable() {                                 @override                                 public void run() {                                     // whatever want front end                                     // can creative                                 }                             });                         }                         break;                     } catch (exception e) {                         handler.post(new runnable() {                             @override                             public void run() {                                 serverstatus.settext("oops. connection interrupted. please reconnect phones.");                             }                         });                         e.printstacktrace();                     }                 }             } else {                 handler.post(new runnable() {                     @override                     public void run() {                         serverstatus.settext("couldn't detect internet connection.");                     }                 });             }         } catch (exception e) {             handler.post(new runnable() {                 @override                 public void run() {                     serverstatus.settext("error");                 }             });             e.printstacktrace();         }     } }  // gets ip address of phone's network private string getlocalipaddress() {     try {         (enumeration<networkinterface> en = networkinterface.getnetworkinterfaces(); en.hasmoreelements();) {             networkinterface intf = en.nextelement();             (enumeration<inetaddress> enumipaddr = intf.getinetaddresses(); enumipaddr.hasmoreelements();) {                 inetaddress inetaddress = enumipaddr.nextelement();                 if (!inetaddress.isloopbackaddress()) {                      boolean isipv4 = inetaddressutils.isipv4address(inetaddress.gethostaddress().tostring());                     if(isipv4)                     return inetaddress.gethostaddress().tostring(); }             }         }     } catch (socketexception ex) {         log.e("serveractivity", ex.tostring());     }     return null; }  @override protected void onstop() {     super.onstop();     try {          // make sure close socket upon exiting          serversocket.close();      } catch (ioexception e) {          e.printstacktrace();      } } 

client side

@override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_client);      serverip = (edittext) findviewbyid(r.id.server_ip);     connectphones = (button) findviewbyid(r.id.connect_phones);     connectphones.setonclicklistener(connectlistener); }  private onclicklistener connectlistener = new onclicklistener() {      @override     public void onclick(view v) {         if (!connected) {             log.e("clicked", "yes");             serveripaddress = serverip.gettext().tostring();             if (!serveripaddress.equals("")) {                 thread cthread = new thread(new clientthread());                 cthread.start();             }         }     } };  public class clientthread implements runnable {      public void run() {         try {             inetaddress serveraddr = inetaddress.getbyname(serveripaddress);             log.d("clientactivity", "c: connecting...");             socket socket = new socket(serveraddr, serveractivity.serverport);             connected = true;             while (connected) {                 try {                     log.d("clientactivity", "c: sending command.");                     printwriter out = new printwriter(new bufferedwriter(new outputstreamwriter(socket                                 .getoutputstream())), true);                         // issue commands                         out.println("hey server!");                         log.d("clientactivity", "c: sent.");                 } catch (exception e) {                     log.e("clientactivity", "s: error", e);                 }             }             socket.close();             log.d("clientactivity", "c: closed.");         } catch (exception e) {             log.e("clientactivity", "c: error", e);             connected = false;         }     } } } 

i have used between 2 emulators server showing listening on 10.0.2.15

but when go connection not connect

thers no error in logcat have checked between 2 physical devices running android 4.0 3g internet want push android devices running server activity client activity can perform action when client send something.

nothing happens when click connect button

permissions:

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

there's demo bluetooth chat , wifi direct in android sdk. should use bluetooth or wifi. don't think can acvhieve direct connection using cellular network.