gistfile1.java

package com.talkwheel.server.rfactory.ioc;

import java.util.Properties;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;

import com.google.inject.AbstractModule;
import com.google.inject.Inject;

import com.google.inject.*;

/**
 * Created by IntelliJ IDEA.
 * User: jim
 * Date: 3/10/11
 * Time: 2:54 AM
 * To change this template use File | Settings | File Templates.
 */
public class DbModule extends AbstractModule {
  public static Properties properties = new Properties() {{
    put("openjpa.RuntimeUnenhancedClasses", "supported");
    put("openjpa.jdbc.DBDictionary", "org.apache.openjpa.jdbc.sql.H2Dictionary");
    put("openjpa.ConnectionDriverName", "org.h2.Driver");
    put("openjpa.ConnectionURL", "jdbc:h2:mem:twroo1001;DB_CLOSE_DELAY=-1");
    put("openjpa.ConnectionUserName", "sa");
    put("openjpa.ConnectionPassword", "");
    put("openjpa.jdbc.SynchronizeMappings", "buildSchema(ForeignKeys=true)");
    put("openjpa.Log", "SQL=TRACE");
    put("openjpa.jdbc.SchemaFactory", "native(ForeignKeys=true)");
    put("openjpa.jdbc.MappingDefaults", "ForeignKeyDeleteAction=restrict");
    put("openjpa.DynamicEnhancementAgent", "true");
    put("openjpa.DetachState", "all(DetachedStateField=transient)");
    put("openjpa.DynamicDataStructs", "true");
  }};

  private static final ThreadLocal<EntityManager> ENTITY_MANAGER_CACHE
      = new ThreadLocal<EntityManager>();

  public void configure() {
    bind(EntityManagerFactory.class).toProvider(EMFP.class).asEagerSingleton();
    bind(EntityManager.class).toProvider(EMP.class);
  }

  static class EMFP implements Provider<EntityManagerFactory> {


    @Override
    public EntityManagerFactory get() {
      return Persistence.createEntityManagerFactory(null);

    }
  }

  static class EMP implements Provider<EntityManager> {
    @Inject
    public EntityManagerFactory entityManagerFactory;

    @Override
    public EntityManager get() {
      EntityManager entityManager = ENTITY_MANAGER_CACHE.get();
      if (entityManager == null) {
        ENTITY_MANAGER_CACHE.set(entityManager = entityManagerFactory.createEntityManager());
      }
      return entityManager;
    }
  }
}
[...] in server/KernelImpl.java:

  public static void initAll() {

    if (KernelLifecycle.STARTED != KernelLifecycle.current.get()) {

      synchronized (KernelLifecycle.class) {
        if (KernelLifecycle.STARTED != KernelLifecycle.current.get()) {

          new ApplicationInitializer();

        }
      }
    }
  }