Datagram socket udp java android

Question

I have a project to send messages to the Arduino, which is ip 192.168.0.100 and the port is 4444, I'm using a datagram socket and a UDP connection, here is the main, and the logcat of the error, I ran straight into a real machine android, but gave the same error that is giving the virtual machine

MainActivity.java

public class MainActivity extends ActionBarActivity {

 Button botao;


@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    botao = (Button) findViewById(R.id.button1);

    botao.setOnClickListener(new View.OnClickListener() {
    private DatagramSocket socketServer;

    public void run(){


    try {
        socketServer = new DatagramSocket();
        byte buf[] = "/RoboCore/relay/0013A20040A13917/1/1".getBytes();
        DatagramPacket pacote = new DatagramPacket(buf, buf.length,    InetAddress.getByName("192.168.0.100"), 4444);
        DatagramSocket socketClient = new DatagramSocket();

        socketServer.send(pacote);


    } catch (SocketException ex) {
     ex.printStackTrace();
    } catch (IOException ex) {
        ex.printStackTrace();
    }

}
        @Override
        public void onClick(View arg0) {
    run();      
        }
    });


    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment())
                .commit();
    }
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {

    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        return rootView;
    }
}

}

LogCat

07-29 13:11:28.720: E/AndroidRuntime(16118): FATAL EXCEPTION: main
07-29 13:11:28.720: E/AndroidRuntime(16118): android.os.NetworkOnMainThreadException
07-29 13:11:28.720: E/AndroidRuntime(16118):    at        android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1118)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at libcore.io.BlockGuardOs.sendto(BlockGuardOs.java:175)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at libcore.io.IoBridge.sendto(IoBridge.java:473)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at java.net.PlainDatagramSocketImpl.send(PlainDatagramSocketImpl.java:182)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at java.net.DatagramSocket.send(DatagramSocket.java:284)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at com.example.tcctestes.MainActivity$1.run(MainActivity.java:59)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at com.example.tcctestes.MainActivity$1.onClick(MainActivity.java:74)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.view.View.performClick(View.java:4262)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.view.View$PerformClick.run(View.java:17421)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.os.Handler.handleCallback(Handler.java:615)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.os.Handler.dispatchMessage(Handler.java:92)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.os.Looper.loop(Looper.java:137)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at android.app.ActivityThread.main(ActivityThread.java:4944)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at java.lang.reflect.Method.invokeNative(Native Method)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at java.lang.reflect.Method.invoke(Method.java:511)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
07-29 13:11:28.720: E/AndroidRuntime(16118):    at dalvik.system.NativeStart.main(Native Method)
07-29 13:11:36.628: I/Process(16118): Sending signal. PID: 16118 SIG: 9

Yeah, you can't do your networking communication on the main thread. You are required to do so within something like an AsyncTask or a standard thread design and then use a callback to the main thread when what you want has been achieved. — Jay Snayder, Jul 29 '14 at 16:48
could make me an example, a scope, I'm beginner, and not WHAT you meant got it — franciscovefago, Jul 30 '14 at 03:23
Why are you creating two sockets? Unclear what you're asking. — user207421, May 01 '16 at 10:28

msj121 · Answer 1 · 2015-04-14T17:24:11.297

0

Encapsulate your code:

 Thread thread = new Thread(new Runnable(){
        @Override
        public void run() {
//YOUR CODE:
try {
    socketServer = new DatagramSocket();
    byte buf[] = "/RoboCore/relay/0013A20040A13917/1/1".getBytes();
    DatagramPacket pacote = new DatagramPacket(buf, buf.length,    InetAddress.getByName("192.168.0.100"), 4444);
    DatagramSocket socketClient = new DatagramSocket();

    socketServer.send(pacote);


} catch (SocketException ex) {
 ex.printStackTrace();
} catch (IOException ex) {
    ex.printStackTrace();
}
        }
 };
 thread.start();

edited Apr 14 '15 at 17:24

answered Apr 14 '15 at 15:50

msj121

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That is all in your current run code – msj121 Apr 14 '15 at 17:24

Datagram socket udp java android

1 Answers1