By expanding the node corresponding to our customer object, we can see the values
of all of its properties. At this point we should notice that the customerId property
is null , which results in the code attempting to insert a new row with a null
primary key. We have discovered the problem. Now that the problem is known,
fixing the code is trivial. In our example, the easiest way to fix it is to add the
@GeneratedValue annotation to the customerId property of our entity bean.
In this appendix we covered how to debug enterprise applications using NetBeans.
We saw how NetBeans makes debugging remote applications deployed to an
application server as simple as debugging standard Java applications.
We also saw how we can add breakpoints to pause execution of our applications and
either step into or step over each line.
Additionally we saw how we can inspect the values of all variables in scope by
looking at the Local Variables window.