How to cache results of a Spring Data JPA query method without using query cache?

Question

I have a Spring Boot app with Spring Data JPA (hibernate backend) repository classes. I\'ve added a couple custom finder methods, some with specific @Query anno

Answer 1

First I quote your question:

What am I doing wrong?

The way you are trying to name the cache is not appropriate to how hibernate will use it. Check org.hibernate.engine.spi.CacheInitiator which uses org.hibernate.internal.CacheImpl which is based on:

if ( settings.isQueryCacheEnabled() ) {
    final TimestampsRegion timestampsRegion = regionFactory.buildTimestampsRegion(
            qualifyRegionName( UpdateTimestampsCache.REGION_NAME ),
            sessionFactory.getProperties()
    );
    updateTimestampsCache = new UpdateTimestampsCache( sessionFactory, timestampsRegion );
    ...
}

And UpdateTimestampsCache.REGION_NAME (equals to org.hibernate.cache.spi.UpdateTimestampsCache) is what you are missing as the cache name. For the query cache you'll have to use exactly that cache name and no other!

Now few other thoughts related to your problem:

• removing @Cache and setting cache name to org.hibernate.cache.spi.UpdateTimestampsCache will allow your query to be cached with ehcache by hibernate (spring cache abstraction is not involved here)
• setting a hardcoded cache name won't make you happy I'm sure but at least you know why this happens
• Balamaci Serban (the post just below) is painfully right

Below is the configuration from one of my projects where ehcache + @Query + @QueryHints work as expected (ehcache/ehcache-in-memory.xml file):

and hibernate.properties:

hibernate.jdbc.batch_size=20
hibernate.show_sql=true
hibernate.format_sql=true
hibernate.validator.autoregister_listeners=false
hibernate.cache.use_second_level_cache=true
hibernate.cache.use_query_cache=true
hibernate.cache.region.factory_class=org.hibernate.cache.ehcache.EhCacheRegionFactory
hibernate.hbm2ddl.auto=update
net.sf.ehcache.configurationResourceName=ehcache/ehcache-in-memory.xml
hibernate.dialect=org.hibernate.dialect.H2Dialect

and some versions from pom.xml for which my explanation applies:

5.0.6.RELEASE
5.0.5.RELEASE
2.1.0.RELEASE
5.2.13.Final
2.9.4

And the full working test is image.persistence.repositories.ImageRepositoryTest.java found here: https://github.com/adrhc/photos-server/tree/how-to-cache-results-of-a-spring-data-jpa-query-method-without-using-query-cache
Yep, run mvn clean install or change my env.sh if you really want to use my shell scripts. Check then the number of sql queries on behalf of 3x imageRepository.count() call.