Question

I am having a function that does a DB operation and sends a boolean value for success/failure. suppose it fails, i want to send the failure reason as a return value.

for now, i have defined return value as a string. if it is failure i return "failure: reason" and if it is success, i return "success". but this is not good practice.

Answer 1

This is what you use throw exception for. You can very well change your method signature and set the return value to be boolean. Then create a custom Exception class:

public class MyCustomException extends RuntimeException {
    // define error code, error message etc.
    // create getters & setters
}

After that, whenever you find a reason for failure, do this:

if (some_failure_reason == true) {
    throw new MyCustomException(error_code) ;
}

In your controller (or service), catch the exception:

try {
    // call the method in question
} catch (MyCustomException mce) {
    if(mce.getErrorCode() == some_error_code) {
        // do stuff
    }
}