Unfortunately, Msger has stopped. FATAL Exception: main [duplicate]

Answer 1

You should never touch network from the main thread. Implement AsyncTask for network operations.

   private class MyInnerClass extends AsyncTask<String, Void, String> {
       @Override
       protected void onPreExecute() {
       super.onPreExecute();

       }

       @Override
       protected String doInBackground(String params) {

       return "Done";
       }

       @Override
       protected void onPostExecute(String result) {
       super.onPostExecute(result);
       }
   }

Call new MyInnerClass().execute(); from you main Activity and android will automatically call onPreExecute() do whatever you wana do inside this method before your network acess.

Android will then call doInBackground
Do you network related stuff inside doInBackground() and when finished it will automatically call onPostExecute() and the result will be passed as params to this method.

Answer 2

Caused by: android.os.NetworkOnMainThreadException

You are trying to perform a potentially slow network operation on the main thread, this became a fatal exception in Android 3.0+. Simply move runTcpClient() to a new Thread by using an AsyncTask or Loader.

Here is an example: How to fix android.os.NetworkOnMainThreadException?.

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Try this:

class TcpClientTask extends AsyncTask<Void, Void, Void> {
    private static final int TCP_SERVER_PORT = 1234;
    private boolean error = false;

    protected Void doInBackground(Void... arg0) {
        try {
            Socket s = new Socket("10.0.2.2", TCP_SERVER_PORT);
            BufferedReader in = new BufferedReader(new InputStreamReader(s.getInputStream()));
            BufferedWriter out = new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
            //send output msg
            String outMsg = "TCP connecting to " + TCP_SERVER_PORT + System.getProperty("line.separator"); 
            out.write(outMsg);
            out.flush();
            Log.i("TcpClient", "sent: " + outMsg);
            //accept server response
            String inMsg = in.readLine() + System.getProperty("line.separator");
            Log.i("TcpClient", "received: " + inMsg);
            //close connection
            s.close();
        } catch (UnknownHostException e) {
            error = true;
            e.printStackTrace();
        } catch (IOException e) {
            error = true;
            e.printStackTrace();
        }
        return null;
    }

    protected void onPostExecute() {
        if(error) {
            // Something bad happened
        }
        else {
            // Success
        }

    }
}

To use it call: new TcpClientTask().execute();

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I have 1 more question. String inMsg = in.readLine() + System.getProperty("line.separator"); which receives messages, how would I set it up to get it every 15ms or whatever is stable to keep receiving data.

I'm not certain what you are trying to do. But I noticed you only call readLine() once, if you want to read more than one line, use a loop:

StringBuilder msg = new StringBuilder();
String line;
while((line = in.readLine()) != null) // Keep reading until the end of the file is reached
    msg.append(in.readLine()).append(System.getProperty("line.separator"));

StringBuilders create less overhead when adding Strings together, simply use msg.toString() when you want get the whole message.

Answer 3

Try use Small Piece Of Code.But its not good practice.

    StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder()
   .detectNetwork()
   .permitNetwork() //permit Network access 
   .build());

You Can use AsynTask or any Threading Concept. Its May Help