Code to obtain wake lock.

WakeLock.java

 /**
     * Tries to acquire a partial wake lock if not already acquired. Logs errors
     * and gives up trying in case the wake lock cannot be acquired.
     */

    /**
     * Acquire a wake lock if not already acquired.
     *
     * @param context  the context
     * @param wakeLock wake lock or null
     */
    @SuppressLint("Wakelock")
    public static WakeLock acquireWakeLock(Context context,
                                           WakeLock wakeLock) {
        Log.i(TAG, "Acquiring wake lock.");
        try {
            PowerManager powerManager = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
            if (powerManager == null) {
                Log.e(TAG, "Power manager null.");
                return wakeLock;
            }
            if (wakeLock == null) {
                wakeLock = powerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, TAG);
                //noinspection ConstantConditions
                if (wakeLock == null) {
                    Log.e(TAG, "Cannot create a new wake lock.");
                }
                return wakeLock;
            }
            if (!wakeLock.isHeld()) {
                wakeLock.acquire();
                if (!wakeLock.isHeld()) {
                    Log.e(TAG, "Cannot acquire wake lock.");
                }
            }
        } catch (RuntimeException e) {
            Log.e(TAG, e.getMessage(), e);
        }
        return wakeLock;
    }