android camera using flash on and flash off controls

Camera funcationality using flash on and flash off
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                        Camera.Parameters p= camera.getParameters();
                          if (Constants.on_flash == true) {
  toggleButton.setChecked(true);
   Log.i("info", "torch is turn on!");
   p.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
   camera.setParameters(p);
   camera.startPreview();
  } else {
   Log.i("info", "torch is turn off!");
   p.setFlashMode(Camera.Parameters.FLASH_MODE_OFF);
   camera.setParameters(p);
   camera.startPreview();

  }