Question

I work with a Java project and Eclipse(Version 3.6.2) as IDE, in a enum comparison i get a strange behaviour, following an example of the weirdness :

Global Variable :

StatusType status = StatusType.SIGNATURE;

                     

Code :

                String trsStatus = "END";
            if(trsStatus.equals("END") && (this.status.compareTo(StatusType.SIGNATURE) != 0)){
                //Do something
                }

This comparison succeeds and enter in the if block, Why ? In this case the second evaluation(this.status.compareTo(StatusType.SIGNATURE) != 0) of the if statements fail because the result is false ! Why java however enter in the block ???

If i evaluate the expression on the expression watcher of eclipse debugger the value of the statements are :

trsStatus.equals("END") —> true

(this.status.compareTo(StatusType.SIGNATURE) != 0) —> false

I’ve done another test, if i assign the result of the second expression in the if statements to a boolean variable :

boolean sign = (this.status.compareTo(StatusType.SIGNATURE) != 0);

i get this result :

(this.status.compareTo(StatusType.SIGNATURE) != 0) —> false

sign —> true

Why ?!?

How this can be possible ?

Answer 1

Could it be that StatusType overrides compareTo() in some weird way?

Are there any other threads that could be changing the value of the status field?

In any case, you should use equals() or even == rather than compareTo() here.