cleaning hibernate cache between dao tests

[robcos]

Hey robcos,

protected void disableSecondLevelCache() {
this.hibernateTemplate.execute(new HibernateCallback() {
public Object doInHibernate(Session session) throws HibernateException {
session.setCacheMode(CacheMode.IGNORE);
return null;
}
});
}

This disables the first level cache (you are running on the session object)
and again, I'm trying to clean the cache, not to disable it. The only solution seems to call sessionFactory.evict() for each of the classes that need are mapped using hibernate. A similar approach can be taken, although.
/Roberto

[Arthur Loder]

Hi robcos,

This disables the first level cache (you are running on the session object)

Actually, from the CacheMode API:

Controls how the session interacts with the second-level cache and query cache.

-Arthur Loder

[robcos]

Hi robcos,



Actually, from the CacheMode API:

Controls how the session interacts with the second-level cache and query cache.

-Arthur Loder

Oh sorry, I missunderstood that. Thanks for pointing it out.

[Arthur Loder]

Hi robcos,

Here is the original class with an updated disableSecondLevelCache() method so that it clears the cache rather than disabling the Session's use of the cache; it relies on casting the SessionFactory to SessionFactoryImpl:

package org.spring.forum;

import java.util.Collection;
import java.util.Map;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cache.Cache;
import org.hibernate.impl.SessionFactoryImpl;
import org.springframework.orm.hibernate3.HibernateCallback;
import org.springframework.orm.hibernate3.HibernateTemplate;
import org.springframework.test.AbstractTransactionalSpringContextTests;

public abstract class AbstractHibernateCacheClearableTest extends AbstractTransactionalSpringContextTests {

    /** Hibernate template to use for disabling second level cache. */
    private HibernateTemplate hibernateTemplate;
    
    /** Whether to disable second level cache; defaults to true. */
    private boolean disableSecondLevelCache = true;
    
    @Override
    protected void onSetUpInTransaction() throws Exception {
        if (this.disableSecondLevelCache) {
            disableSecondLevelCache();
        }
    }
    
    /**
     * Performs the actual disabling of the Hibernate second-level cache.
     */
    protected void disableSecondLevelCache() {
         this.hibernateTemplate.execute(new HibernateCallback() {
            public Object doInHibernate(Session session) throws HibernateException {
                SessionFactoryImpl sessionFactoryImpl = (SessionFactoryImpl)session.getSessionFactory();
                Map cacheRegionsMap = sessionFactoryImpl.getAllSecondLevelCacheRegions();
                Collection<Cache> cacheRegions = cacheRegionsMap.values();
                for (Cache cache : cacheRegions) {
                    cache.clear();
                }
                return null;
            }
        });     
    }

    /**
     * Sets the HibernateTemplate for disabling the Hibernate second-level
     * cache.
     * 
     * @param hibernateTemplate the HibernateTemplate for disabling the
     *            Hibernate second-level cache.
     */
    public void setHibernateTemplate(HibernateTemplate hibernateTemplate) {
        this.hibernateTemplate = hibernateTemplate;
    }

    /**
     * Sets whether to disable the Hibernate second-level cache. Defaults to
     * true.
     * 
     * @param disableSecondLevelCache whether to disable the Hibernate
     *            second-level cache.
     */
    public void setDisableSecondLevelCache(boolean disableSecondLevelCache) {
        this.disableSecondLevelCache = disableSecondLevelCache;
    }

    /**
     * Checks whether disabling of Hibernate second-level cache should occur.
     * Can be overridden by subclasses to return false to allow second-level
     * cache usage (or the disableSecondLevelCache can be set to false, either
     * programmatically or through injection).
     * 
     * @return whether disabling of Hibernate second-level cache should occur.
     */
    public boolean isDisableSecondLevelCache() {
        return this.disableSecondLevelCache;
    }
    
}

The above code calls Cache.clear for every cache region. An alternative method implementation that might work is defined below, which retrieves all mapped classes and calls Session.evictEntity for each:

protected void disableSecondLevelCache() {                                                                                                                         
    this.hibernateTemplate.execute(new HibernateCallback() {                                  
        public Object doInHibernate(Session session) throws HibernateException {                 
            SessionFactoryImpl sessionFactoryImpl = (SessionFactoryImpl)session.getSessionFactory();
            // Every persistent class extends java.lang.Object, so the following call will return all persistent classes
            String[] persistentClasses = sessionFactoryImpl.getImplementors("java.lang.Object");    
            for (String persistentClass : persistentClasses) {                             
                sessionFactoryImpl.evictEntity(persistentClass);                              
            }                                                                              
            return null;                                                                            
        }                                                                                  
    });                                                                                       
}

The relevant APIs are SessionFactoryImpl.getAllSecondLevelCacheRegions and SessionFactoryImpl.getImplementors.

I hope one of those implementations actually works!

-Arthur Loder

[robcos]

Hi robcos,
Here is the original class with an updated disableSecondLevelCache() method so that it clears the cache rather than disabling the Session's use of the cache; it relies on casting the SessionFactory to SessionFactoryImpl:

I like it, thank you!
Anyway, it is maybe safer to use the interface "SessionFactoryImplementor" instead of the class "SessionFactoryImpl"

/roberto