springdata之jpa的crud.

初始化

  private EntityManagerFactory managerFactory;

    @Before
    public void init(){
         managerFactory = Persistence.createEntityManagerFactory("myjpa");
    }

//添加的方法

    @Test
    public void addCutomer(){
        EntityManager entityManager = managerFactory.createEntityManager();
        EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();
        for (int i = 0; i <10 ; i++) {
            Customer customer = new Customer();
            customer.setCustName("测试"+i);
            customer.setCustAddress("张三"+i);
            customer.setCustLevel("白卡"+i);
            customer.setCustPhone("12345"+i);
            entityManager.persist(customer);
        }
        transaction.commit();
        entityManager.close();
    }

//删除的方法

  @Test
    public void deleteCustomer(){
        EntityManager entityManager = managerFactory.createEntityManager();
        EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();
        Customer customer = entityManager.find(Customer.class, 1L);
        entityManager.remove(customer);
        transaction.commit();
        entityManager.close();
    }

//修改的方法

 @Test
    public void updateCustomer(){
        EntityManager entityManager = managerFactory.createEntityManager();
        EntityTransaction transaction = entityManager.getTransaction();
        transaction.begin();
        Customer customer = entityManager.find(Customer.class, 2L);
        customer.setCustName("张安");
        customer.setCustPhone("66666");
        customer.setCustLevel("钻石卡");
        entityManager.merge(customer);
        transaction.commit();
        entityManager.close();
    }

//根据ID查询【getReference】的方法，

 @Test
    public void getCustomer(){
        EntityManager entityManager = managerFactory.createEntityManager();
        Customer customer = entityManager.getReference(Customer.class, 2L);
        // 延时加载  getReference方法执行之后  访问对象的属性时 才执行
        System.out.println("我执行了");
        System.out.println(customer);
        entityManager.close();
    }

//根据ID查询【find】的方法

  @Test
    public void findCustomer(){
        EntityManager entityManager = managerFactory.createEntityManager();
        Customer customer = entityManager.find(Customer.class, 2L);
        //  该方法  是及时加载   find方法执行之后 sql 语句执行
        System.out.println("我执行了");
        System.out.println(customer);
        entityManager.close();
    }

上一篇文章有六个步骤，可以参考上面文章进行测试。