Java verifying an enum value passed as an argument

Question

I have the following enum

public enum State {
    UNCHECKED, SUBMITTED, VALIDATED, REJECTED, ENTITLED;
}

and in another class I have a method that receives a State as an argument, like this

public void validate (State state) throws InvalidStateException {
    if (state != State.VALIDATED || state != State.REJECTED) 
        throw new InvalidStateException(); 
}

this method should throw the exception InvalidStateException only when the argument State isn't either State.VALIDATED or State.REJECTED but is in fact throwing it always. I just can't see where the mistake can be or how could I write the code in another way that would work.

I know that this isn't working because the following JUnit Test says the mentioned exception is being thrown and it shouldn't:

@Test
public void testValidate () throws InvalidStateException {
    object.validate(State.VALIDATED);
}

Use `&&` instead of `||` on your IF! – Jorge Campos Jan 24 '16 at 00:21 — Jorge Campos, Jan 24 '16 at 00:21

score 2 · Answer 1 · answered Jan 24 '16 at 00:21

2

The condition state != State.VALIDATED || state != State.REJECTED is always true. the only way for it to be false would be for state to be VALIDATED and REJECTED at the same time.

You want &&, not ||.

answered Jan 24 '16 at 00:21

JB Nizet

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Yes, I noticed that last night! When I corrected it everything went perfectly. Thanks – black_stripes Jan 25 '16 at 09:24

Java verifying an enum value passed as an argument

1 Answers1