JBOSS Arquillian : How to force database to throw exception while running the aquillian test? - jpa

Question

I am implementing a feature where if there is any exception while writing data into DB, we should retry it for 5 times before failing. I have implemented the feature but not able to test it using arquillian test.
We are using JPA and Versant as database. Till now, I am debbuging the the arquillian test and once my flow reaches DB handler code, I am stopping the database. But this is worst way of testing.
Do you have any suggestion how to achieve the same ?

Answer 1

With JPA in mind, the easiest way is to add method to your data access layer, with which you are able to run native queries. Then you run query against nonexisting table or something similar. So in my DAO utilities I found method like this:
public List findByNativeQuery(String nativeQuery, Map<String, Object> args) {
try{
final EntityManager em = getEntityManager();
final Query query = em.createNativeQuery(nativeQuery);
if (args!=null && args.entrySet().size()>0) {
final Iterator it = args.entrySet().iterator();
while (it.hasNext()) {
final Map.Entry pairs = (Map.Entry)it.next();
query.setParameter(pairs.getKey().toString(), pairs.getValue());
}
}
return query.getResultList();
}
catch (RuntimeException e) {
// throw some new Exception(e.getMessage()); // the best is to throw checked exception
}
}

Answer 2

Native solutions
There is the old trick by dividing by zero in the database. At the time of selection you could try:
select 1/0 from dual;
Insertion time (you need a table):
insert into test_table (test_number_field) values (1/0);
pure JPA solution
You can try to utilize the #Version annotation and decrement it to throw OptimisticLockException. This is not thrown in the database, but in the Java layer, but fullfills your need.
Those all will result in DB fail.