While migrating a project of mine from JPA2 to Avaje Ebean, I encountered a issue, I wasn’t expecting.

Avaje Ebean does not support the JPA EntityListener Annotations, like

@PrePersist,
@PostPersist,
@PreUpdate,
@PostUpdate,
@PostLoad


Some nice folks on the Ebean Mailinglist directed me to some Documentation about EntityListeners in Ebean including a helpful forum link which finally pointed me to the BeanPersistController Interface in the Ebean Java API .
With that Information, I was able to create a EntityListener that enables the use of the JPA EntityListener Annotations with Ebean.

This Gist shows how I’ve done it:

	package models.sgcore;
	import com.avaje.ebean.event.BeanPersistAdapter;
	import com.avaje.ebean.event.BeanPersistRequest;
	import javax.annotation.PreDestroy;
	import javax.persistence.*;
	import java.lang.reflect.InvocationTargetException;
	import java.lang.reflect.Method;
	import java.util.HashMap;
	import java.util.Map;
	import java.util.Set;
	import java.util.TreeMap;
	/**
	* This is a <code>BeanPersistController</code> that looks for methods annotated with the JPA Annotations
	* <code>@PrePersist</code>
	* <code>@PostPersist</code>
	* <code>@PreUpdate</code>
	* <code>@PostUpdate</code>
	* <code>@PreDestroy</code>
	* <code>@PostLoad</code>
	*
	* registers those methods with this Listener and calls them when necessary.
	*/
	public class SGBeanPersistController extends BeanPersistAdapter {
	private Map<String,Method> prePersistMap = new TreeMap<String, Method>();
	private Map<String,Method> postPersistMap = new TreeMap<String, Method>();
	private Map<String,Method> preUpdateMap = new TreeMap<String, Method>();
	private Map<String,Method> postUpdateMap = new TreeMap<String, Method>();
	private Map<String,Method> preDestroyMap = new TreeMap<String, Method>();
	private Map<String,Method> postLoadMap = new TreeMap<String, Method>();
	@Override
	public boolean isRegisterFor(Class<?> aClass) {
	if(aClass.getAnnotation(Entity.class) != null){
	System.out.println("Registering a Entity; Type is " + aClass.toString());
	Method[] methods = aClass.getMethods();
	boolean hasListener = false;
	for(Method m : methods)
	{
	// System.out.println("looking if method " + m.toString() + " has Annotation on it. ");
	if(m.isAnnotationPresent(PrePersist.class))
	{
	prePersistMap.put(aClass.getName(), m);
	hasListener = true;
	}
	if(m.isAnnotationPresent(PostPersist.class))
	{
	postPersistMap.put(aClass.getName(), m);
	hasListener = true;
	}
	if(m.isAnnotationPresent(PreDestroy.class))
	{
	preDestroyMap.put(aClass.getName(), m);
	hasListener = true;
	}
	if(m.isAnnotationPresent(PreUpdate.class))
	{
	preUpdateMap.put(aClass.getName(), m);
	hasListener = true;
	}
	if(m.isAnnotationPresent(PostUpdate.class))
	{
	postUpdateMap.put(aClass.getName(), m);
	hasListener = true;
	}
	if(m.isAnnotationPresent(PostLoad.class))
	{
	postLoadMap.put(aClass.getName(), m);
	hasListener = true;
	}
	}
	return hasListener;
	}
	return false;
	}
	private void getAndInvokeMethod(Map<String,Method> map, Object o)
	{
	Method m = map.get(o.getClass().getName());
	if(m != null)
	try {
	m.invoke(o);
	} catch (IllegalAccessException e) {
	e.printStackTrace();
	} catch (InvocationTargetException e) {
	e.printStackTrace();
	}
	}
	@Override
	public boolean preInsert(BeanPersistRequest<?> request) {
	getAndInvokeMethod(prePersistMap, request.getBean());
	return super.preInsert(request);
	}
	@Override
	public boolean preDelete(BeanPersistRequest<?> request) {
	getAndInvokeMethod(preDestroyMap, request.getBean());
	return super.preDelete(request);
	}
	@Override
	public boolean preUpdate(BeanPersistRequest<?> request) {
	getAndInvokeMethod(preUpdateMap, request.getBean());
	return super.preUpdate(request);
	}
	@Override
	public void postDelete(BeanPersistRequest<?> request) {
	// there is no @PostDestroy annotation in JPA 2
	super.postDelete(request);
	}
	@Override
	public void postInsert(BeanPersistRequest<?> request) {
	getAndInvokeMethod(postPersistMap, request.getBean());
	super.postInsert(request);
	}
	@Override
	public void postUpdate(BeanPersistRequest<?> request) {
	getAndInvokeMethod(postUpdateMap, request.getBean());
	super.postUpdate(request);
	}
	@Override
	public void postLoad(Object bean, Set<String> includedProperties) {
	getAndInvokeMethod(postLoadMap, bean);
	super.postLoad(bean, includedProperties);
	}
	}

view raw SGBeanPersistController.java hosted with by GitHub

Questions? Comments? Forks?

I appreciate any kind of feedback!