Turn on/off camera flash light programmatically in Android

Step 1)
Add the below permission to manifest.xml 
<uses-permission android:name="android.permission.CAMERA" />  
<uses-permission android:name="android.permission.FLASHLIGHT"/>  

Step 2)
Check programmatically the availability of flashlight in device .

context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH);

It returns true if flash is available .

Step 3)
Turn on camera flash light LED.

Camera cam = Camera.open();     
Parameters p = cam.getParameters();
p.setFlashMode(Parameters.FLASH_MODE_TORCH);
cam.setParameters(p);
cam.startPreview();

Step 4)
Turn off camera flash light LED.

cam.stopPreview();
cam.release();