Android Flashlight

public class Flashlight extends Activity {

    private static Camera cam = null;
    private Camera.Parameters par;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_flashlight);
        Context context = this;
        PackageManager packageManager = context.getPackageManager();
        blink();
       }

     @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.flashlight, 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);
    }


    public void blink() {
            for (int i = 0; i < 10; i++) {
                cameraon();
                cameraoff();
       }
    }


    public void cameraon() {

        if (getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA_FLASH)) {
            cam = Camera.open();
            try {

                cam.setPreviewTexture(new SurfaceTexture(0));

            } catch (IOException e) {
                e.printStackTrace();
            }
            par = cam.getParameters();
            par.setFlashMode(par.FLASH_MODE_ON);
            par.setFlashMode(par.FLASH_MODE_TORCH);
            cam.setParameters(par);
            cam.startPreview();
        }
    }

     public void cameraoff(){

        par.setFlashMode(par.FLASH_MODE_OFF);
        cam.setParameters(par);
        cam.stopPreview();
        cam.release();
        cam = null;
    }
}