[Q] Check whether device is rooted or not programmatically? - Android Q&A, Help & Troubleshooting

Hello guys,
I would like to take your best suggestions and help for this issue. I have written function to check whether my device is rooted or not? Actually this function is working properly with other devices excepting Samsung Galaxy S4 MINI and Galaxy S5 rooted device. So we can say it is not working to the level of 100%. So kinldy help me to solve this issue and give your best suggestions with effective solution which can work on all the devices.
My Code is something like below :
Code:
/**
* Checks if the device is rooted.
*
* @return <code>true</code> if the device is rooted, <code>false</code> otherwise.
*/
public static boolean isRooted() {
// get from build info
String buildTags = android.os.Build.TAGS;
if (buildTags != null && buildTags.contains("test-keys")) {
return true;
}
// check if /system/app/Superuser.apk is present
try {
File file = new File("/system/app/Superuser.apk");
if (file.exists()) {
return true;
}
} catch (Exception e1) {
// ignore
}
// try executing commands
return canExecuteCommand("/system/xbin/which su")
|| canExecuteCommand("/system/bin/which su") || canExecuteCommand("which su");
}
// executes a command on the system
private static boolean canExecuteCommand(String command) {
boolean executedSuccesfully;
try {
Runtime.getRuntime().exec(command);
executedSuccesfully = true;
} catch (Exception e) {
executedSuccesfully = false;
}
return executedSuccesfully;
}
Waiting for your reply guys ASAP,
Thanks