Spring Data JPA结合Mybatis进行分页查询的实现

@Entity
public class User {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String name;

    private Integer age;

    // ...

}

public interface UserRepository extends CrudRepository<User, Long> {
    // ...
}

public interface UserMapper {
    List<User> findPage(Map<String, Object> params);
}

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.demo.mapper.UserMapper">

    <select id="findPage" resultType="com.example.demo.entity.User">
        SELECT * FROM user
        LIMIT #{offset}, #{pageSize}
    </select>

</mapper>

@Service
public class UserService {

    @Autowired
    private UserRepository userRepository;

    @Autowired
    private UserMapper userMapper;

    public Page<User> findPage(Integer pageNum, Integer pageSize) {

        Map<String, Object> params = new HashMap<>();
        params.put("offset", (pageNum - 1) * pageSize);
        params.put("pageSize", pageSize);

        List<User> users = userMapper.findPage(params);

        // 使用 PageHelper 进行分页
        Page<User> page = new Page<>(pageNum, pageSize);
        page.setTotal(users.size());
        page.setRecords(users);

        return page;
    }

}

@Controller
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/users")
    public String list(Model model, Integer pageNum, Integer pageSize) {

        Page<User> page = userService.findPage(pageNum, pageSize);

        model.addAttribute("page", page);

        return "users";
    }

}