Code hook before EntityManager is initialized in JBoss AS 6

Question

Hi *,

I'm looking for a callback facility that allows me to execute some code before an EntityManager is started in JBoss 6.

More specifically, I would like to process a Liquibase changelog, before the EntityManager is initialized.

Any hints greatly appreciated! J.

Answer 1

Are you using Spring or AspectJ? It sounds like writing an aspect is exactly what you want:

7.2.4.1 Before advice

Before advice is declared in an aspect using the @Before annotation:

import org.aspectj.lang.annotation.Aspect;
import org.aspectj.lang.annotation.Before;

@Aspect
public class LiquibaseChangelogAspect {

  @Before("javax.persistence.EntityManagerFactory.createEntityManager()")
  public void processChangelog() {
    // ...
  }

}

You might have to tweak the method name in the @Before annotation to exactly what you want because JBoss might be using proxies or whatever.