mybatis-plus分页

1. 定义一个 Mapper 接口，继承 BaseMapper，用于操作数据库：

javaCopy codeimport com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Repository;

@Mapper
@Repository
public interface UserMapper extends BaseMapper<User> {
}

1. 在你的 Service 类中，注入上面定义的 Mapper，并实现分页查询方法：

javaCopy codeimport com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    public Page<User> getUsersByPage(int pageNum, int pageSize) {
        Page<User> page = new Page<>(pageNum, pageSize);
        
        // 这里可以根据需要添加查询条件
        QueryWrapper<User> queryWrapper = new QueryWrapper<>();
        
        // 执行分页查询
        Page<User> resultPage = userMapper.selectPage(page, queryWrapper);
        
        return resultPage;
    }
}

1. 在你的 Controller 中，调用 Service 的分页查询方法并返回结果：

javaCopy codeimport com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/users")
public class UserController {

    @Autowired
    private UserService userService;

    @GetMapping("/page")
    public Page<User> getUsersByPage(
            @RequestParam(defaultValue = "1") int pageNum,
            @RequestParam(defaultValue = "5") int pageSize) {
        return userService.getUsersByPage(pageNum, pageSize);
    }