hibernate: join table

I'm not sure how to join tables in hibernate. Say i have a table called news and another table as news_categories. The news table has a primary key as id, which also serves as a foreign key for table news_categories. Now i need to find out the categories for each news in the news table, how can i do that in hibernate?

here is my code to get the news:

HibernateEntityManagerFactory hmf = (HibernateEntityManagerFactor开发者_如何学Pythony) _emf;
SessionFactory sf = hmf.getSessionFactory();
Session ss = sf.openSession();

ScrollableResults srq = ss.createCriteria(news.class)
            .addOrder(Order.desc(("_creationDate")))
            .setCacheMode(CacheMode.IGNORE)
            .scroll(ScrollMode.FORWARD_ONLY);
..

on srq add .createAlias("newsCategories")

This way the the categories will be fetched together with the news items.