springboot 整合 mybatis plus -- 分页查询

先根据 springboot 整合 mybatis plus  这篇生成各种文件

controller：

package com.lifan.controller;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.lifan.request.AcUserReq;
import com.lifan.response.AcUserResp;
import com.lifan.service.AcUserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;

/**
 * <p>
 *  前端控制器
 * </p>
 *
 * @author lifan
 * @since 2021-07-09
 */
@RestController
public class AcUserController {

    @Autowired
    private AcUserService acUserService;

    @PostMapping("/Query")
    public IPage<AcUserResp> SspFxProChannelQuery(@RequestBody AcUserReq req) {

        return acUserService.listPage(req);
    }
}

service接口：

package com.lifan.service;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.lifan.entity.AcUser;
import com.baomidou.mybatisplus.extension.service.IService;
import com.lifan.request.AcUserReq;
import com.lifan.response.AcUserResp;

/**
 * <p>
 *  服务类
 * </p>
 *
 * @author lifan
 * @since 2021-07-09
 */
public interface AcUserService extends IService<AcUser> {

    IPage<AcUserResp> listPage(AcUserReq req);

}

AcUserServiceImpl  实现类：

package com.lifan.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.lifan.entity.AcUser;
import com.lifan.mapper.AcUserMapper;
import com.lifan.request.AcUserReq;
import com.lifan.response.AcUserResp;
import com.lifan.service.AcUserService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import org.springframework.beans.BeanUtils;
import org.springframework.stereotype.Service;
import java.util.ArrayList;
import java.util.List;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author lifan
 * @since 2021-07-09
 */
@Service
public class AcUserServiceImpl extends ServiceImpl<AcUserMapper, AcUser> implements AcUserService {

    @Override
    public IPage<AcUserResp> listPage(AcUserReq req) {

        Page<AcUser> page = new Page<AcUser>(req.getPage(),req.getPageSize());
        LambdaQueryWrapper<AcUser> lambdaQueryWrapper = new LambdaQueryWrapper();

        //如果传了 name 属性，可根据 name 进行模糊匹配
        if(req.getName() != null){
            lambdaQueryWrapper.like(AcUser::getName,req.getName());
        }

        // Type 属性，Y为启用，  N为冻结 。 （相当于where条件过滤）
        if(req.getType() != null){
            lambdaQueryWrapper.eq(AcUser::getType,req.getType());
        }

        IPage<AcUser> iPage = this.page(page,lambdaQueryWrapper);

        List<AcUserResp> list = new ArrayList<>();

        for (AcUser acUser : iPage.getRecords ()) {
            AcUserResp resp = new AcUserResp ();
            BeanUtils.copyProperties (acUser,resp);
            list.add (resp);
        }

        System.out.println(list);
        IPage<AcUserResp> respIPage = new Page<> ();
        BeanUtils.copyProperties (iPage,respIPage);
        respIPage.setRecords (list);
        return respIPage;
    }
}

Mapper 接口：

package com.lifan.mapper;

import com.lifan.entity.AcUser;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import org.apache.ibatis.annotations.Mapper;

/**
 * <p>
 *  Mapper 接口
 * </p>
 *
 * @author lifan
 * @since 2021-07-09
 */
@Mapper
public interface AcUserMapper extends BaseMapper<AcUser> {


}

实体类：

package com.lifan.entity;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableId;
import java.io.Serializable;
import lombok.Data;
import lombok.EqualsAndHashCode;
import lombok.experimental.Accessors;

/**
 *
 * @author lifan
 * @since 2021-07-09
 */
@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
public class AcUser implements Serializable {

    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.ID_WORKER_STR)
    private Integer id;

    private String name;

    private String type;

}

AcUserReq 接受请求类：

package com.lifan.request;

import lombok.Data;

/**
 *
 * @author lifan
 * @since 2021-07-09
 */
@Data
public class AcUserReq {

    private String name;

    private String type;

    private int page;

    private int pageSize;


}

AcUserResp 请求返回类：

package com.lifan.response;

import lombok.Data;

/**
 * @author lifan
 * @since 2021-07-09
 */
@Data
public class AcUserResp{

    private Integer id;

    private String name;

    private String type;


}

AcUserMapper.xml

<?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.lifan.mapper.AcUserMapper">

</mapper>

测试结果：

（参数也可加 name 和 type 属性）

数据库：

SQL语句：

/*
 Navicat Premium Data Transfer

 Source Server         : localhost
 Source Server Type    : MySQL
 Source Server Version : 80023
 Source Host           : localhost:3306
 Source Schema         : ac-new

 Target Server Type    : MySQL
 Target Server Version : 80023
 File Encoding         : 65001

 Date: 09/07/2021 18:32:50
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for ac_user
-- ----------------------------
DROP TABLE IF EXISTS `ac_user`;
CREATE TABLE `ac_user`  (
  `id` int(0) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  `type` varchar(255) CHARACTER SET utf8 COLLATE utf8_general_ci NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of ac_user
-- ----------------------------
INSERT INTO `ac_user` VALUES (1, 'li-1', 'Y');
INSERT INTO `ac_user` VALUES (2, 'li-2', 'Y');
INSERT INTO `ac_user` VALUES (3, 'li-3', 'N');
INSERT INTO `ac_user` VALUES (4, 'li-4', 'N');
INSERT INTO `ac_user` VALUES (5, 'wang-5', 'Y');
INSERT INTO `ac_user` VALUES (6, 'wang-6', 'Y');
INSERT INTO `ac_user` VALUES (7, 'wang-7', 'N');
INSERT INTO `ac_user` VALUES (8, 'wang-8', 'N');

SET FOREIGN_KEY_CHECKS = 1;