JTA Container Managed Transaction Example

package com.sapient.impl;

import javax.ejb.Stateless;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.ejb.TransactionManagement;
import javax.ejb.TransactionManagementType;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import com.sapient.entities.Book;
import com.sapient.spec.BookDAO;

@Stateless
@TransactionManagement(TransactionManagementType.CONTAINER)
public class BookDAOEJB implements BookDAO{
   
    @PersistenceContext
    private EntityManager em;       

    @Override
   
    @TransactionAttribute(TransactionAttributeType.REQUIRED)
    public void saveBook(Book b) {
            System.out.println("---- saveBook method(***) called ----");
            em.persist(b);
           
    }

    @Override
    @TransactionAttribute(TransactionAttributeType.SUPPORTS)
    public Book findBookById(String id) {
        Book bookFromDB = em.find(Book.class, id);
        System.out.println("---- BookDAO EJB Loading book with id "+id);
        return bookFromDB;
    }

}