NullPointerException from Boolean

Question

This is one for the java purists I think. I recently had an issue with a method to perform a custom parsing of String values to a Boolean. A simple enough task, but for some

Answer 1

This also works:

static Boolean parseBoolean(String s)
{
    return ("1".equals(s) ? Boolean.TRUE : ("0".equals(s) ? Boolean.FALSE : null));
}

So the reason you get an NPE is due to autoboxing because using boolean in the ternary operator causes the result of the expression to be treated as a boolean. And un-boxing of null causes an NPE.