Re: Wrapping persistence strategy exceptions into RollerExceptions

[Craig L Russell]

Hi,






Craig

On Oct 10, 2006, at 1:34 PM, Mitesh Meswani wrote:

It's not obvious to me that we should be catching NPE and wrapping them. I wasn't part of the original design, but it seems that catching NPE would tend to hide the actual source of the problem, and it would be better to have the highest level code that knew enough to catch Exception actually do this. OOTH, I believe that catching SQLException, JPAException, and JDOException and wrapping them in RollerException does make sense.

Hi Markus,





Thanks,
Mitesh

Markus Fuchs wrote:

I think it should be enough to make sure that persistence related exceptions are caught and rethrown as RollerException as you have shown in your example below. Do you think catching all RuntimeExcpetion, like SQLExceptions or NullPointerExceptions (which most probably should be due to bugs in the persistence provider's code) and rethrowing them as (checked) RollerExceotion would add any value?

Thank you!

Mitesh, Craig,



-- markus.

Allen Gilliland wrote:

Shall catch all RuntimeExceptions then and re-throw them as RollerExceptions?

Markus,



-- Allen


Markus Fuchs wrote:

I don't think there is really a perfect answer to your question, but I think that in general any exceptions that are specific to the persistence implementation should be caught and rethrown as a RollerException. Whether or not to catch RuntimeExceptions could probably be debated, but I think in general it's preferable to catch them and rethrow as a normal RollerException.

Hi all,

I'm helping Mitesh implementing the persistence layer abstraction
for roller.


RollerExceptions by the strategy implementation. All persistence
layers throw RuntimeExceptions: PersistenceExceptions for JPA,
JDOExceptions for JDO or HibernateExceptions for Hibernate.

Should strategy specific RuntimeExceptions be wrapped into checked

something like:

  public void flush() throws RollerException {
      try {
          EntityManager em = getEntityManager(false);
          if (isTransactionActive(em)) {
              em.getTransaction().commit();
          }
          em.close();
      } catch (PersistenceException e) {
          throw new RollerException(e);
      }
  }


E.g. SQLExceptions or NullPointerExceptions?

Thanks,

-- markus.

I'm wondering, if strategy specific exceptions should be wrapped into RollerExceptions? E.g. in JPAPersistenceStrategy, we could implement Also, should be same be done for other persistence layer related exceptions?

Craig Russell
Architect, Sun Java Enterprise System http://java.sun.com/products/jdo
408 276-5638 mailto:[EMAIL PROTECTED]
P.S. A good JDO? O, Gasp!

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