spring整合jpa

package com.lushuifa.dao; import javax.persistence.EntityManager; import javax.persistence.EntityManagerFactory; import javax.persistence.EntityTransaction; import javax.persistence.Persistence; import javax.persistence.PersistenceContext; import org.springframework.transaction.annotation.Transactional; import com.lushuifa.po.Users; @Transactional public class UserDao { @PersistenceContext private EntityManager em; public EntityManager getEm() { return em; } public void setEm(EntityManager em) { this.em = em; } /** * 添加用户 * @param user */ public void addUsers(Users user){ try { this.em.persist(user); } catch (Exception e) { e.printStackTrace(); } } public void delUsers(int id){ try { this.em.remove(this.findUserById(id)); } catch (Exception e) { e.printStackTrace(); } } public Users findUserById(int id){ Users user = this.em.find(Users.class,1); return user; } }