How to set a HikariCP DataSource as the JPA DataSource?

[Ryan Asleson]

I'm sure a lot of this is because of my inexperience with JPA (I have a lot more experience with JDO) but the more I learn of JPA, the less I like it, mostly because of its over-reliance on the persistence.xml configuration and the inability to configure programmatically via Java.

Anyway, when I'm using JPA, how do I tell the EntityManagerFactory to use a HikariCP data source, rather than specifying a JNDI data source?  I've searched and searched but all I find is how to configure persistence.xml to look up a JNDI data source by name.

I'm creating my own HikariCP data source objects and I simply want to tell the JPA EntityManagerFactory to use that data source.

How do I do that?  It shouldn't be this hard.  I must be missing something.

Thank you!!!

-Ryan

[Brett Wooldridge]

Does the wiki page for Spring+Hibernate help?

https://github.com/brettwooldridge/HikariCP/wiki/Spring-Hibernate

That recipe was provided by somebody else, but appears to allow setting the
DataSource into the EntityManager ... in the case of Spring via the
LocalContainerEntityManagerFactoryBean.

-Brett

[Ryan Asleson]

Thanks, I'll take a look.  Right now I'm building a proof of concept app that isn't using Spring so I was hoping to avoid another jar.  The "real" app would eventually use Spring in some fashion, I'm sure, but for now I was hoping to avoid it.

I'll take a look and keep looking around, too.

[Ryan Asleson]

OK, I was able to do it using Spring's LocalContainerEntityManagerFactoryBean object.  I think it's a real strike against JPA that one has to use an external framework consisting of six other jars to create an EntityManagerFactory using a given DataSource, but oh well.  

Thank you!

[Brett Wooldridge]

Everywhere I've searched for an answer has basically come up empty Re: setting up JPA in Tomcat without JNDI.  But I'm glad you

found a configuration that works.

-Brett

[Ryan Asleson]

For those who may stumble upon this later, here's what I did.  

Notes:

1.  dataSource is the HikariCP DataSource you created yourself.

2.  This assumes that you have a persistence.xml somewhere on the classpath, as you normally would.  Spring will create the EntityManagerFactory based on the settings in persistence.xml but will use the DataSource you provided.  I think you can set more properties here that will override what's in persistence.xml but I didn't do that myself.

3.  Be sure to call the afterPropertiesSet() method.  It's important!  That method actually triggers the creation of the EntityManagerFactory, otherwise calling getNativeEntityManagerFactory will return null.

      LocalContainerEntityManagerFactoryBean factoryBean = new LocalContainerEntityManagerFactoryBean();

      factoryBean.setDataSource(dataSource);

      factoryBean.setPersistenceUnitName("persistenceUnitName");

      factoryBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());

      factoryBean.afterPropertiesSet();

      factory = factoryBean.getNativeEntityManagerFactory();