Inject persistence service into my service class

[Ben Longi, modificado hace 12 años.]

Hello,
I'm writing an hook to change JournalArticle behaviour.

My service class extends JournalArticleLocalServiceWrapper and I'm overiding getDisplayArticle(long groupId, String articleId) method.
In this method I need to make a call to the database using the JournalArticlePersistence class.

List<journalarticle> articles = journalArticlePersistence.findByG_A_ST(....)</journalarticle>

However that object is null in my service context. I tried to inject the bean

	@BeanReference(type = JournalArticlePersistence.class)
	protected JournalArticlePersistence journalArticlePersistence;

I though it could work because my hook inherit the default liferay spring configuration. But actually It doesn't work.
How can I use a Liferay Persistence service in my own service class ? Should I use service builder ? I'd like to avoid service builder because my need is really simple here...

Thanks