title: android bluetooth activation error
body: <p>I am trying to activate bluetooth programatically in android and the application installs fine, but when I click the button to activate BT , it gives exception. I am not able to handle the exception. Any help is greatly appreciated. I am new to this.  Here is the code : </p>
  
  <pre><code>package com.example.helloandroid2;
  
  
  import java.io.IOException;
  
  import android.app.Activity;
  import android.bluetooth.BluetoothAdapter;
  import android.content.Context;
  import android.content.Intent;
  import android.os.Bundle;
  import android.view.View;
  import android.view.View.OnClickListener;
  import android.widget.Button;
  import android.widget.EditText;
  import android.widget.TextView;
  import android.widget.Toast;
  
  public class HelloAndroid extends Activity {
   // Declare our Views, so we can access them later
  
   private Button activate_buletooth;
      static final int REQUEST_ENABLE_BT = 0;
      Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
      BluetoothAdapter mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
      /** Called when the activity is first created. */
      @Override
      public void onCreate(Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
  
          // Set Activity Layout
          setContentView(R.layout.main);
  
           activate_buletooth = (Button)findViewById(R.id.activate_buletooth);
  
          // Set Click Listener
  
              activate_buletooth.setOnClickListener(new OnClickListener() {
           @Override
           public void onClick(View v){
            if (mBluetoothAdapter == null) {
                // Device does not support Bluetooth
             Context context = getApplicationContext();
             CharSequence text = "BT not suported";
             int duration = Toast.LENGTH_SHORT;
  
             Toast toast = Toast.makeText(context, text, duration);
             toast.show();
            }     
            if (!mBluetoothAdapter.isEnabled()) {
                Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
            }
  
            // startActivityForResult(discoverableIntent, REQUEST_ENABLE_BT);
  
           }
          });
  
      }
      @Override
      protected void onActivityResult(int requestCode, int resultCode, Intent data)
      {
       if(requestCode == REQUEST_ENABLE_BT)
          {
        if(resultCode == RESULT_CANCELED)
              {
         Context context = getApplicationContext();
         CharSequence text = "bt not available";
         int duration = Toast.LENGTH_SHORT;
  
         Toast toast = Toast.makeText(context, text, duration);
         toast.show();
              }
         else
               {
  
               }
          }
      }
  }
  </code></pre>