title: R.java file is not there
body: <p>The below given is the code for MyActivity.java file.</p>
  
  <pre><code>package com.technomentis.ledonoff;
  
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.UUID;
  
  
  import android.app.Activity;
  import android.bluetooth.BluetoothAdapter;
  import android.bluetooth.BluetoothDevice;
  import android.bluetooth.BluetoothSocket;
  import android.content.Intent;
  import android.os.Bundle;
  import android.util.Log;
  import android.view.View;
  import android.view.View.OnClickListener;
  import android.widget.Button;
  import android.widget.Toast;
  import android.R;
  
  public class MainActivity extends Activity {
      private static final String TAG = "LEDOnOff";
  
      Button btnOn, btnOff;
  
      private static final int REQUEST_ENABLE_BT = 1;
      private BluetoothAdapter btAdapter = null;
      private BluetoothSocket btSocket = null;
      private OutputStream outStream = null;
  
      // Well known SPP UUID
      private static final UUID MY_UUID =
              UUID.fromString("00001101-0000-1000-8000-00805F9B34FB");
  
      // Insert your server's MAC address
      private static String address = "00:00:00:00:00:00";
  
      /** Called when the activity is first created. */
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
          Log.d(TAG, "In onCreate()");
  
          setContentView(R.layout.main);
  
          btnOn = (Button) findViewById(R.id.btnOn);
          btnOff = (Button) findViewById(R.id.btnOff);
  
          btAdapter = BluetoothAdapter.getDefaultAdapter();
          checkBTState();
  
          btnOn.setOnClickListener(new OnClickListener() {
              public void onClick(View v) {
                  sendData("1");
                  Toast msg = Toast.makeText(getBaseContext(),
                          "You have clicked On", Toast.LENGTH_SHORT);
                  msg.show();
              }
          });
  
          btnOff.setOnClickListener(new OnClickListener() {
              public void onClick(View v) {
                  sendData("0");
                  Toast msg = Toast.makeText(getBaseContext(),
                          "You have clicked Off", Toast.LENGTH_SHORT);
                  msg.show();
              }
          });
      }
  
      @Override
      public void onResume() {
          super.onResume();
  
          Log.d(TAG, "...In onResume - Attempting client connect...");
  
          // Set up a pointer to the remote node using it's address.
          BluetoothDevice device = btAdapter.getRemoteDevice(address);
  
          // Two things are needed to make a connection:
          //   A MAC address, which we got above.
          //   A Service ID or UUID.  In this case we are using the
          //     UUID for SPP.
          try {
              btSocket = device.createRfcommSocketToServiceRecord(MY_UUID);
          } catch (IOException e) {
              errorExit("Fatal Error", "In onResume() and socket create failed: " + e.getMessage() + ".");
          }
  
          // Discovery is resource intensive.  Make sure it isn't going on
          // when you attempt to connect and pass your message.
          btAdapter.cancelDiscovery();
  
          // Establish the connection.  This will block until it connects.
          Log.d(TAG, "...Connecting to Remote...");
          try {
              btSocket.connect();
              Log.d(TAG, "...Connection established and data link opened...");
          } catch (IOException e) {
              try {
                  btSocket.close();
              } catch (IOException e2) {
                  errorExit("Fatal Error", "In onResume() and unable to close socket during connection failure" + e2.getMessage() + ".");
              }
          }
  
          // Create a data stream so we can talk to server.
          Log.d(TAG, "...Creating Socket...");
  
          try {
              outStream = btSocket.getOutputStream();
          } catch (IOException e) {
              errorExit("Fatal Error", "In onResume() and output stream creation failed:" + e.getMessage() + ".");
          }
      }
  
      @Override
      public void onPause() {
          super.onPause();
  
          Log.d(TAG, "...In onPause()...");
  
          if (outStream != null) {
              try {
                  outStream.flush();
              } catch (IOException e) {
                  errorExit("Fatal Error", "In onPause() and failed to flush output stream: " + e.getMessage() + ".");
              }
          }
  
          try     {
              btSocket.close();
          } catch (IOException e2) {
              errorExit("Fatal Error", "In onPause() and failed to close socket." + e2.getMessage() + ".");
          }
      }
  
      private void checkBTState() {
          // Check for Bluetooth support and then check to make sure it is turned on
  
          // Emulator doesn't support Bluetooth and will return null
          if(btAdapter==null) {
              errorExit("Fatal Error", "Bluetooth Not supported. Aborting.");
          } else {
              if (btAdapter.isEnabled()) {
                  Log.d(TAG, "...Bluetooth is enabled...");
              } else {
                  //Prompt user to turn on Bluetooth
                  Intent enableBtIntent = new Intent(btAdapter.ACTION_REQUEST_ENABLE);
                  startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
              }
          }
      }
  
      private void errorExit(String title, String message){
          Toast msg = Toast.makeText(getBaseContext(),
                  title + " - " + message, Toast.LENGTH_SHORT);
          msg.show();
          finish();
      }
  
      private void sendData(String message) {
          byte[] msgBuffer = message.getBytes();
  
          Log.d(TAG, "...Sending data: " + message + "...");
  
          try {
              outStream.write(msgBuffer);
          } catch (IOException e) {
              String msg = "In onResume() and an exception occurred during write: " + e.getMessage();
              if (address.equals("00:00:00:00:00:00"))
                  msg = msg + ".\n\nUpdate your server address from 00:00:00:00:00:00 to the correct address on line 37 in the java code";
              msg = msg +  ".\n\nCheck that the SPP UUID: " + MY_UUID.toString() + " exists on server.\n\n";
  
              errorExit("Fatal Error", msg);
          }
      }
  }
  </code></pre>
  
  <p>I am getting following errors,</p>
  
  <pre><code>Error:(46, 32) error: cannot find symbol variable main
  Error:(49, 43) error: cannot find symbol variable btnOn
  Error:(50, 44) error: cannot find symbol variable btnOff
  </code></pre>
  
  <p>Btw I am using Android Studio. And new to android development.</p>