Spring hibernate ehcache setup

Question

I have some problems getting the hibernate second level cache to work for caching domain objects. According to the ehcache documentation it shouldn't be too complicated to add caching to my existing working application.

I have the following setup (only relevant snippets are outlined):

@Entity
@Cache(usage = CacheConcurrencyStrategy.NONSTRICT_READ_WRITE
public void Entity {
    // ... 
}

ehcache-entity.xml

<cache name="com.company.Entity" eternal="false"
    maxElementsInMemory="10000" overflowToDisk="true" diskPersistent="false"
    timeToIdleSeconds="0" timeToLiveSeconds="300"
    memoryStoreEvictionPolicy="LRU" />

ApplicationContext.xml

<bean class="org.springframework.orm.hibernate3.annotation.AnnotationSessionFactoryBean">
    <property name="dataSource" ref="ds" />
    <property name="annotatedClasses">
        <list>
            <value>com.company.Entity</value>
        </list>
    </property>
    <property name="hibernateProperties">
        <props>
            <prop key="hibernate.generate_statistics">true</prop>
            <prop key="hibernate.cache.use_second_level_cache">true</prop>
            <prop key="net.sf.ehcache.configurationResourceName">/ehcache-entity.xml</prop>
            <prop key="hibernate.cache.region.factory_class">net.sf.ehcache.hibernate.SingletonEhCacheRegionFactory</prop>
            .... 
    </property>
</bean>

Maven dependencies

   <dependency>
        <groupId>org.hibernate</groupId>
        <artifactId>hibernate-annotations</artifactId>
        <version>3.4.0.GA</version>
    </dependency>

    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-hibernate3</artifactId>
        <version>2.0.8</version>
        <exclusions>
            <exclusion>
                <artifactId>hibernate</artifactId>
                <groupId>org.hibernate</groupId>
            </exclusion>
        </exclusions>
    </dependency>

    <dependency>
        <groupId>net.sf.ehcache</groupId>
        <artifactId>ehcache-core</artifactId>
        <version>2.3.2</version>
    </dependency>

A test class is used which enables cache statistics:

    Cache cache = cacheManager.getCache("com.company.Entity");
    cache.setStatisticsAccuracy(Statistics.STATISTICS_ACCURACY_GUARANTEED);
    cache.setStatisticsEnabled(true);
    // store, read etc ... 
    cache.getStatistics().getMemoryStoreObjectCount(); // returns 0

No operation seems to trigger any cache changes. What am I missing? Currently I'm using HibernateTemplate in the DAO, perhaps that has some impact.

[EDIT]

The only ehcache log output when set to DEBUG is:

SettingsFactory: Cache region factory : net.sf.ehcache.hibernate.SingletonEhCacheRegionFactory

Solution 1

There were several causes that I've identified:

1. Correct maven dependencies:

   <dependency>
       <groupId>org.hibernate</groupId>
       <artifactId>hibernate-core</artifactId>
       <version>3.6.3.Final</version>
   </dependency>
   
   <dependency>
       <groupId>net.sf.ehcache</groupId>
       <artifactId>ehcache-core</artifactId>
       <version>2.4.1</version>
   </dependency>
   

2. Added the @Cacheable annotation from javax.persistence to my entities.

3. Read logging from hibernate instead of ehcache.

   getSessionFactory().getStatistics().logSummary();

4. Not all hibernate operations seems to affect the cache. This I need to read up on further.

Solution 2

Do you need to manually tell Hibernate to use the EHCache provider? I've never really been sure if this is required, but Hibernate does support a number of cache providers so I suspect that it might be necessary to explicitly tell Hibernate which one you want. Try adding this property to ApplicationContext.xml:

<prop key="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</prop>