Question

I have the following piece of code

 try{//do something
     }
  catch (Exception e) {
        log.error(e, e);
        if (e instanceof RuntimeException) {
            throw (RuntimeException) e;
        } else {
            throw new RuntimeException(e);
        }
    }

the findbugs stataic analysis tool throws this warning on it

instanceof will always return true for all nonnull values in methodX, since all RuntimeException are instances of RuntimeException

what i dont understand is that its Exception which is being caught and not the RuntimeException, so why this warning ?

Answer 1

You could also try following code. This will be better to read and maintain.

try{//do something
}
catch (RuntimeException e) {
    throw e;
} 
catch (Exception e) {
    throw new RuntimeException(e);
}