Postgres v. HSQL ConstrainViolationException Wrapping in Spring

Question

I have a weird behavior difference I'd like to understand. I have Bean Validation annotations in an entity class. I also have some code that catches them and them formats them as JSON for a REST interface -- but I think this is not impacting anything. I am using Spring and JPA Hibernate.

When I set HSQL as my database driver, I can catch the ConstrainViolationException directly after an EntityManager #persist invocation. However, when I switch the JDBC driver to Postgres #persist will throw a TransactionSystemException caused by a RollbackException then finally in the RollbackException I can get at the ConstraintViolationException. The code is identical, I only switch the driver. The #persist method is @Transactional.

Now I suppose I can workaround this by adding a catch for TransactionSystemExeption and getting the cause twice to get to the ConstraintViolationException to process, but it seems weird to me that I would need two catch clauses for identical code depending only on the driver configuration. Any thoughts or explanations?

The setup is simple. Any JPA entity with a @NotNull bean constraint on some field. Then persist it in a method that is transactional. With HSQL you will get an exception like this:

javax.validation.ConstraintViolationException: Validation failed for classes [MyEntity] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='not a well-formed email address', propertyPath=emailAddress, rootBeanClass=class ..., messageTemplate='{org.hibernate.validator.constraints.Email.message}'}
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=password, rootBeanClass=class ..., messageTemplate='{javax.validation.constraints.NotNull.message}'}
]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:161)
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreInsert(BeanValidationEventListener.java:94)
    at org.hibernate.action.EntityIdentityInsertAction.preInsert(EntityIdentityInsertAction.java:160)
    at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:65)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
    at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:320)
    at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
    at org.hibernate.ejb.event.EJB3PersistEventListener.saveWithGeneratedId(EJB3PersistEventListener.java:69)
    at org.hibernate.event.def.DefaultPersistEventListener.entityIsTransient(DefaultPersistEventListener.java:179)
    at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:135)
    at org.hibernate.event.def.DefaultPersistEventListener.onPersist(DefaultPersistEventListener.java:61)
    at org.hibernate.impl.SessionImpl.firePersist(SessionImpl.java:808)
    at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:782)
    at org.hibernate.impl.SessionImpl.persist(SessionImpl.java:786)
    at org.hibernate.ejb.AbstractEntityManagerImpl.persist(AbstractEntityManagerImpl.java:837)
    at sun.reflect.GeneratedMethodAccessor21.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:601)
    at org.springframework.orm.jpa.SharedEntityManagerCreator$SharedEntityManagerInvocationHandler.invoke(SharedEntityManagerCreator.java:240)
    at $Proxy49.persist(Unknown Source)

While with PostgreSQL you will get this exception. Do not change any code, just change the driver and dialect to PostgreSQL and catch the exception.

    org.springframework.transaction.TransactionSystemException: Could not commit JPA transaction; nested exception is javax.persistence.RollbackException: Error while committing the transaction
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:521)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.processCommit(AbstractPlatformTransactionManager.java:754)
    at org.springframework.transaction.support.AbstractPlatformTransactionManager.commit(AbstractPlatformTransactionManager.java:723)
    at org.springframework.transaction.interceptor.TransactionAspectSupport.commitTransactionAfterReturning(TransactionAspectSupport.java:393)
    at org.springframework.transaction.aspectj.AbstractTransactionAspect.ajc$afterReturning$org_springframework_transaction_aspectj_AbstractTransactionAspect$3$2a73e96c(AbstractTransactionAspect.aj:78)
    at EntityService.persist(EntityService.java:82)
    ...
Caused by: javax.persistence.RollbackException: Error while committing the transaction
    at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:93)
    at org.springframework.orm.jpa.JpaTransactionManager.doCommit(JpaTransactionManager.java:512)
    ... 47 more
Caused by: javax.validation.ConstraintViolationException: Validation failed for classes [MyEntity] during persist time for groups [javax.validation.groups.Default, ]
List of constraint violations:[
    ConstraintViolationImpl{interpolatedMessage='not a well-formed email address', propertyPath=emailAddress, rootBeanClass=class MyEntity, messageTemplate='{org.hibernate.validator.constraints.Email.message}'}
    ConstraintViolationImpl{interpolatedMessage='may not be null', propertyPath=password, rootBeanClass=class MyEntity, messageTemplate='{javax.validation.constraints.NotNull.message}'}
]
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.validate(BeanValidationEventListener.java:161)
    at org.hibernate.cfg.beanvalidation.BeanValidationEventListener.onPreInsert(BeanValidationEventListener.java:94)
    at org.hibernate.action.EntityInsertAction.preInsert(EntityInsertAction.java:178)
    at org.hibernate.action.EntityInsertAction.execute(EntityInsertAction.java:72)
    at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
    at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:184)
    at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
    at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
    at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
    at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)
    at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)
    at org.hibernate.ejb.TransactionImpl.commit(TransactionImpl.java:76)
    ... 48 more

Answer 1

Unfortunately, hibernate does not handle validation in a driver agnostic manner. As a result you will have to catch these exceptions differently depending on the database. Do not assume you can write your entity exception and validation handling code in a database independent manner.