第九篇：Spring Boot整合Spring Data JPA_入门试炼05

JpaRepository接口
前言：该接口继承了PagingAndSortingRepository接口。对继承的父接口中方法的返回值进行适配。
例如：父接口中的方法的返回值是是迭代器，而在子类(JpaRepository)返回值是Lis集合。
1、持久层接口：

public interface UsersJpaRepository extends JpaRepository<Users,Integer> {
}

测试类

@RunWith(SpringRunner.class)
@SpringBootTest
public class UsersJpaRepositoryTest {


    @Autowired
    private UsersJpaRepository usersJpaRepository;

    @Test
    public void save() {
        Users u = new Users();
        u.setName("zhangsan");
        u.setAge(22);
        u.setAddress("zhongguohaidian");
        usersJpaRepository.save(u);
    }

    /**
     * RepositoryPagingAndSorting 接口排序
     */
    @Test
    public void pagingAndSorting() {
        //order 定义排序规则
        Sort.Order order = new Sort.Order(Sort.Direction.DESC, "id");
        //sort对象封装了排序规则
        Sort sort = new Sort(order);
        List<Users> list = usersJpaRepository.findAll(sort);
        for (Users users : list) {
            System.out.println(users);
        }
    }
}

本文源码下载：

github地址：
​​​https://github.com/gb-heima/Spring-Boot-Actual-Combat/tree/master/parent/spring-boot-chapter-9​​