springboot08-jpa-mysql

1.主要pom依赖：

<!--jpa-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <!--mysql-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

2.userDao：

public interface UserDao extends JpaRepository<User, Long>{

    User findByUserName(String userName);
    User findByUserNameAndPassword(String userName, String password);
}

这里继承JpaRepository后，会有主要的增删改查方法，还有查询所有list(), 分页查询list() 等基础方法。如果要自定义方法，可根据jpa标准来定义，比如：

//根据用户名查询单个用户：  User findOneByUserName(String userName);

//根据用户名查询多个用户：  List<User> findAllByUserName(String userName);

3.测试:

@RunWith(SpringRunner.class)
@SpringBootTest(classes = MainApp.class)
public class ServiceTest {

    @Autowired
    private UserDao userDao;
    @Autowired
    private UserService userService;

    private ObjectMapper objectMapper = new ObjectMapper();

    @Test
    public void testAll() throws JsonProcessingException {

        this.saveUser();
        this.list();

    }

    private void saveUser() throws JsonProcessingException {
        User admin = new User();
        admin.setUserName("admin");
        admin.setPassword("admin");
        User adminSave = userDao.save(admin);
        System.out.println("admin save--->:" + objectMapper.writeValueAsString(adminSave));
        User user = new User();
        user.setUserName("user");
        user.setPassword("user");
        User userSave = userDao.save(user);
        System.out.println("user save--->:" + objectMapper.writeValueAsString(userSave));
    }

    private void list() throws JsonProcessingException {
        List<User> userList = userService.userList();
        System.out.println("用户列表：" + objectMapper.writeValueAsString(userList));
    }

}

结果：

Hibernate: insert into user (password, user_name) values (?, ?)
admin save--->:{"id":1,"userName":"admin","password":"admin"}
Hibernate: insert into user (password, user_name) values (?, ?)
user save--->:{"id":2,"userName":"user","password":"user"}

Hibernate: select user0_.id as id1_0_, user0_.password as password2_0_, user0_.user_name as user_nam3_0_ from user user0_
用户列表：[{"id":1,"userName":"admin","password":"admin"},{"id":2,"userName":"user","password":"user"}]

源码地址：https://github.com/yangzhenlong/mySpringBootDemo