null pointer on String

Don French

I get an NPE in the String class. Not sure what causes this or how to fix it. It kind of looks like a Javelin bug. One other question, when trying to debug the code, it tells me that there are no line numbers in one of my classes. Is there a switch I have to set to get line numbers, or what?

Don French

Well, I fixed it but I don't understand yet. The unhandled NPE occurred in the construction of an object of a class of mine. I had code like this:


public class ClassA {

static ClassB rf = new ClassB(1, 2);

public static void main(){
return;
}

and I changed it to code like this:
public class ClassA {

static ClassB rf;

public static void main(){
rf = new ClassB(1, 2);
return;
}

and the NPE went away. Why is this?

Don French

I was also wondering why String NPEs are not handled. It would be very useful if the exception handler printed a stack trace, for example. Not possible?

Peter Verkaik

I think the error originates in classB.
Moving the creation of a new classB into main() made the
error disappear because main() only gets to run after
the initialization of all used classes is done.
Without seeing the actual classes used, that is my best guess.
If you use debug instead of just program, you can single step
your code and it will show a call/stack trace.

regards peter

Joss

What does ClassB look like?

Regards