<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid</artifactId>
    <version>1.0.28</version>
</dependency>
<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
</dependency>

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.username=root
spring.datasource.password=123456
spring.datasource.url=jdbc:mysql://localhost:3307/jpa?useSSL=true&serverTimezone=UTC&characterEncoding=UTF-8
#jpa connect mysql
spring.jpa.database=mysql
#jpa show sql
spring.jpa.show-sql=true
#jpa format sql
spring.jpa.properties.hibernate.format_sql=true
#create-drop create update validate
spring.jpa.hibernate.ddl-auto=update

public interface IUserDao extends JpaRepository<User, Integer> {
    List<User> findByPassword(String password);
    List<User> findByUsername(String username);
}

public interface IUserService {
    List<User> getAllUsers();
    void saveUsers(User u);
    List<User> getUsersByPassword(String password);
    List<User> getUsersByUsername(String username);
}

@Service
public class UserServiceImpl implements IUserService {
    @Resource
    private IUserDao userDao;
    @Override
    public List<User> getAllUsers() {
        return userDao.findAll();
    }
    @Override
    public void saveUsers(User u) {
        userDao.saveAndFlush(u);
    }
    @Override
    public List<User> getUsersByPassword(String password) {
        return userDao.findByPassword(password);
    }
    @Override
    public List<User> getUsersByUsername(String username) {
        return userDao.findByUsername(username);
    }
}

//@RunWith(SpringRunner.class)
@SpringBootTest
public class TestUserService {
    @Resource
    private IUserService userService;
    @Test
    public void testSaveUser(){
        User u = new User(0, "wangwu", "999999", "beijing");
        userService.saveUsers(u);
    }
    @Test
    public void testGetUsersByUsername(){
        for (User user : userService.getUsersByUsername("zhangsan")) {
            System.out.println(user);
        }
    }
    @Test
    public void testGetUsersByPassword(){
        for (User user : userService.getUsersByPassword("999999")) {
            System.out.println(user);
        }
    }
}

Hibernate: 
    select
        user0_.col_uid as col_uid1_0_,
        user0_.addr as addr2_0_,
        user0_.col_password as col_pass3_0_,
        user0_.col_username as col_user4_0_ 
    from
        tbl_user user0_ 
    where
        user0_.col_username=?
User(uid=1, username=zhangsan, password=999999, addr=beijing)

@RestController
public class UserController {
    @Resource
    private IUserService userService;
    @GetMapping("/Users")
    public List<User> getAllUsers(){
        return userService.getAllUsers();
    }
    ```

[{"uid":1,"username":"zhangsan","password":"999999","addr":"beijing"},
{"uid":2,"username":"lisi","password":"999999","addr":"beijing"},
{"uid":3,"username":"wangwu","password":"999999","addr":"beijing"}]