@Cacheable on entity findAll causes hibernate exception

[lili5058]

I used Roo to build a JPA/Hibernate application and I now want to make use of Spring's Cache abstraction that came out in 3.1.

when I add @Cacheable(value = "subjects") like so to the Roo generated method (after pushing the method into the main class:

	@Cacheable(value="subjects")
	public static List<Subject> findAllSubjects() {
        return entityManager().createQuery("SELECT o FROM Subject o", Subject.class).getResultList();
    }

I get the follow error:

Data access failure

Sorry, a problem occurred while accessing the database.

Details
org.hibernate.InstantiationException: Could not instantiate entity: edu.wisc.acadprop.domain.Subject; nested exception is javax.persistence.PersistenceException: org.hibernate.InstantiationException: Could not instantiate entity: edu.wisc.acadprop.domain.Subject
org.springframework.orm.jpa.EntityManagerFactoryUtils.convertJpaAccessExceptionIfPossible(EntityManagerFactoryUtils.java:326)
org.springframework.orm.jpa.aspectj.JpaExceptionTranslatorAspect.ajc$afterThrowing$org_springframework_orm_jpa_aspectj_JpaExceptionTranslatorAspect$1$18a1ac9(JpaExceptionTranslatorAspect.aj:15)

Here are my relevant configurations:

ehcache.xml

<?xml version="1.0" encoding="UTF-8"?> 
<ehcache xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:noNamespaceSchemaLocation="http://ehcache.org/ehcache.xsd"> 
	<defaultCache maxElementsInMemory="1000" eternal="false" overflowToDisk="true" memoryStoreEvictionPolicy="LFU" />
	<cache name="subjects" maxElementsInMemory="500" eternal="false" overflowToDisk="false"
		memoryStoreEvictionPolicy="LFU" />
</ehcache>

applicationContext.xml

    <bean id="cacheManager" class="org.springframework.cache.ehcache.EhCacheCacheManager">
    	<property name="cacheManager" ref="ehcache"></property>
    </bean>

	<bean id="ehcache" class="org.springframework.cache.ehcache.EhCacheManagerFactoryBean">
		<property name="configLocation" value="classpath:ehcache.xml"></property>
	</bean>

If I comment out @Cacheable, things work fine.

What am I missing?

[delgad9]

@lili5058,

Yours is a List collection coming from a JPA datasource...
JPA spec has its way for doing caching. I recall someone publishing in this forum the configuration for enabling using JPA-hibernate.
Dig a litter more and you will find it.

I hope this helps you
jD