RootChecker.java

public static boolean isEmulator() {
    return Build.FINGERPRINT.startsWith("generic")
            || Build.FINGERPRINT.startsWith("unknown")
            || Build.MODEL.contains("google_sdk")
            || Build.MODEL.contains("Emulator")
            || Build.MODEL.contains("Android SDK built for x86")
            || Build.MANUFACTURER.contains("Genymotion")
            || (Build.BRAND.startsWith("generic") && Build.DEVICE.startsWith("generic"))
            || "google_sdk".equals(Build.PRODUCT);
}

public static boolean isRooted(Context context) {
    boolean isEmulator = !isRealDevice(context);
    String buildTags = Build.TAGS;
    if (!isEmulator && buildTags != null && buildTags.contains("test-keys")) {
        return true;
    } else {
        File file = new File("/system/app/Superuser.apk");
        if (file.exists()) {
            return true;
        } else {
            file = new File("/system/xbin/su");
            return !isEmulator && file.exists();
        }
    }
}

public static boolean isRealDevice(Context context) {
    String androidId = android.provider.Settings.Secure.getString(context.getContentResolver(),
            android.provider.Settings.Secure.ANDROID_ID);
    SensorManager manager = (SensorManager) context.getSystemService(SENSOR_SERVICE);

    return (!isEmulator()
            && (androidId != null
            || !androidId.equals("")
            || !androidId.equals("null")
            || !androidId.equals("NULL"))
            && (Build.SERIAL != null
            || !Build.SERIAL.equals("")
            || !Build.SERIAL.equals(" ")
            || !Build.SERIAL.equals("null")
            || !Build.SERIAL.equals("NULL")
            || !Build.SERIAL.equals("unknown"))
            && !manager.getSensorList(Sensor.TYPE_ALL).isEmpty());
}