Home/ Questions/Q 8833215
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-14T08:43:37+00:00

I am trying to establish a connection between Android Client and C# Server ..

  • 0

I am trying to establish a connection between Android Client and C# Server .. My server is working fine except the android client is not working even after adding internet connection permission

Here is the code :

    private void connectSocket(String a){ 

    try { 
        InetAddress serverAddr = InetAddress.getByName("192.168.0.2"); 
        Log.d("TCP", "C: Connecting....");

        Socket socket = new Socket(serverAddr,4444); 
        Log.d("TCP", "C: I dunno ...");
        //String message = "1";

        PrintWriter out = null;
        BufferedReader in = null;

        try { 
          //  Log.d("TCP", "C: Sending: '" + message + "'"); 
            out = new PrintWriter( new BufferedWriter( new OutputStreamWriter(socket.getOutputStream())),true); 
            in = new BufferedReader(new InputStreamReader(socket.getInputStream()));                

            //out.println(message);
            while ((in.readLine()) != null) {
            txt.append(in.readLine());
            }

            Log.d("TCP", "C: Sent."); 
            Log.d("TCP", "C: Done.");               

        } catch(Exception e) { 
            Log.e("TCP", "S: Error", e); 
        } finally { 
            socket.close(); 
        } 

    } catch (UnknownHostException e) { 
        // TODO Auto-generated catch block 
        Log.e("TCP", "C: UnknownHostException", e); 
        e.printStackTrace(); 
    } catch (IOException e) { 
        // TODO Auto-generated catch block 
        Log.e("TCP", "C: IOException", e); 
        e.printStackTrace(); 
    }       
}

And here is the Debugging Log: 

11-15 02:41:58.040: W/dalvikvm(26839): threadid=1: thread exiting with uncaught exception (group=0x41c352a0)
11-15 02:41:58.075: E/AndroidRuntime(26839): FATAL EXCEPTION: main
11-15 02:41:58.075: E/AndroidRuntime(26839): android.os.NetworkOnMainThreadException
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at libcore.io.BlockGuardOs.connect(BlockGuardOs.java:84)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at libcore.io.IoBridge.connectErrno(IoBridge.java:127)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at libcore.io.IoBridge.connect(IoBridge.java:112)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:192)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:172)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.net.Socket.startupSocket(Socket.java:566)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.net.Socket.<init>(Socket.java:225)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at com.example.socketclient.SocketCode.connectSocket(SocketCode.java:50)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at com.example.socketclient.SocketCode.access$0(SocketCode.java:44)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at com.example.socketclient.SocketCode$1.onClick(SocketCode.java:35)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.view.View.performClick(View.java:4211)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.view.View$PerformClick.run(View.java:17267)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.os.Handler.handleCallback(Handler.java:615)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.os.Handler.dispatchMessage(Handler.java:92)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.os.Looper.loop(Looper.java:137)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at android.app.ActivityThread.main(ActivityThread.java:4898)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.lang.reflect.Method.invokeNative(Native Method)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at java.lang.reflect.Method.invoke(Method.java:511)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1006)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:773)
11-15 02:41:58.075: E/AndroidRuntime(26839):    at dalvik.system.NativeStart.main(Native Method)
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    By the looks of it you are trying to perform networking operation on the main thread. Take a look at the log trace specially line android.os.NetworkOnMainThreadException.

    Android Developer: Network on Main Thread Exception

    Always do networking on a separate thread other than main. There are different ways to accomplish that as well e.g. you can use AsyncTask or start thread on your own.

    There are several posts on SO for this and Android Developer site. Here are a few links to get you going:

    Android Developer: Connecting to the network

    Android Developers Blog: Multithreading for performance

    • 0