Spring / Hibernate: how to get Configuration from LocalContainerEntityManagerFactoryBean

Question

I'd like to run Configuration.generateSchemaUpdateScriptList(). However Hibernate is configured using LocalContainerEntityManagerFactoryBean. How do I get to the Configuration object from a LocalContainerEntityManagerFactoryBean instance? Or is there a better way to achieve this?

Why do you need to run `Configuration.generateSchemaUpdateScriptList()`? — M. Deinum, Dec 02 '14 at 19:11
Obviously because I want to get Hibernate's idea of how to update the schema to match the entities, but do something else with it rather than just apply it as is. — Amir Abiri, Dec 04 '14 at 11:38

score 2 · Accepted Answer · edited May 23 '17 at 12:23

OK this was a two-days wall vs. head marathon, but in the end I found a solution, although it's somewhat hacky.

I cam across Hibernate's Integrator, which is scarcely mentioned in the docs. Some more information about it can be found in the linked Hibernate JIRA issues HHH-5562 and HHH-6081. However, one can piece together enough information for a working example from a few sources once you know the keyword. Still it does not play well with Spring, a problem mentioned in this SO question.

So, the final solution was a bit hackish, but it works:

public class GetConfigIntegrator implements Integrator {

    private static Configuration configuration;

    public static Configuration getConfiguration() {
        return configuration;
    }

    @Override
    public void integrate(Configuration configuration, /* ... */) {
        GetConfigIntegrator.configuration = configuration;
    }

    // Empty Integrator implementation...
}

As can be seen, this silly integrator simply stores the configuration in a static variable, so it can be accessed later. Not ideal, but faced with no options one rejoices finding such a path.

To register the integrator, the following file needs to be created, with one line per integrator class (full name), like so:

# src/main/resources/META-INF/services/org.hibernate.integrator.spi.Integrator:
<full package name>.GetConfigIntegrator

Spring / Hibernate: how to get Configuration from LocalContainerEntityManagerFactoryBean

1 Answers1