io.apiman.manager.api.jpa

Class JpaUtil

java.lang.Object

io.apiman.manager.api.jpa.JpaUtil

public final class JpaUtil
extends Object

Some utility methods for JPA support.

Author:

eric.wittmann@redhat.com

Constructor Summary

Constructors

Constructor and Description
JpaUtil()

Method Summary

Methods

Modifier and Type	Method and Description
static boolean	isConstraintViolation(Exception e) Returns true if the given exception is a unique constraint violation.
static void	rollbackQuietly(javax.persistence.EntityManager entityManager) Rolls back a transaction.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

JpaUtil

public JpaUtil()

Method Detail

isConstraintViolation

public static boolean isConstraintViolation(Exception e)

Returns true if the given exception is a unique constraint violation. This is useful to detect whether someone is trying to persist an entity that already exists. It allows us to simply assume that persisting a new entity will work, without first querying the DB for the existence of that entity. Note that my understanding is that JPA is supposed to throw an EntityExistsException when the row already exists. However, this is not always the case, based on experience. Or perhaps it only throws the exception if the entity is already loaded from the DB and exists in the EntityManager.

Parameters:

e - the exception

Returns:

whether a constraint violation occurred

rollbackQuietly

public static void rollbackQuietly(javax.persistence.EntityManager entityManager)

Rolls back a transaction. Tries to be smart and quiet about it.

Parameters:

entityManager - the entity manager