On 2011-03 -29, at 08:43, Paul Harrison wrote:
as Racks are the basic containers for all other objects and there need to be two pre-existing for the application to be able to function - stationRack and baselineRack are static members of Rack. The code that does the equivalent of what causes the error below runs fine in a unit test - so it seems that it is running within Netbeans RCP that the problem occurs - perhaps it is to do with an interaction between the classloading requirements of Eclipselink and Netbeans RCP....
Actually I was looking and the unit test does other things first - if I isolate the unit test to do exactly what is happening in Netbeans RCP then exactly the same happens (the NPE) in a pure unit test - the following is the first (non-static) piece of code
RackJpaController jpa = new RackJpaController();
List<Rack> rackList = jpa.findRackEntities();
so there seems to be an interaction between the static initialization in Rack
static {
try {
RackJpaController instance = new RackJpaController();
if((stationRack = instance.findRack(Integer.valueOf(255))) == null){
stationRack = new Rack(Integer.valueOf(255));
stationRack.setName("Station");
instance.create(stationRack);
}
if((baselineRack = instance.findRack(Integer.valueOf(101))) == null){
baselineRack = new Rack(Integer.valueOf(101));
baselineRack.setName("Baseline");
instance.create(baselineRack);
}
} catch (PreexistingEntityException e) {
throw new RuntimeException("A Rack has already been created", e);
} catch (Exception e) {
throw new RuntimeException("Error creating rack", e);
}
}
and the use of Rack as the List generic type specifier - the code for the jpa.findRackEntities() is
public List<Rack> findRackEntities() {
return findRackEntities(true, -1, -1);
}
public List<Rack> findRackEntities(int maxResults, int firstResult) {
return findRackEntities(false, maxResults, firstResult);
}
private List<Rack> findRackEntities(boolean all, int maxResults, int firstResult) {
EntityManager em = getEntityManager();
try {
CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
cq.select(cq.from(Rack.class));
Query q = em.createQuery(cq);
if (!all) {
q.setMaxResults(maxResults);
q.setFirstResult(firstResult);
}
return q.getResultList();
} finally {
em.close();
}
}
I can work round this problem by creating an instance of Rack before the "List<Rack> rackList = jpa.findRackEntities();" to get the static initializers done separately.
I can send you a complete maven project with just the relevant classes if you want to investigate the issue further...
Regards,
Paul.
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