springboot中分页插件的使用

安装依赖

这里有个版本的报错，循环依赖的问题，大家可以去具体查下，我这是sp3,所以要选择高点的版本，否则启动会报错

xml 复制代码

<!--mybatis起步依赖-->
  <dependency>
      <groupId>org.mybatis.spring.boot</groupId>
      <artifactId>mybatis-spring-boot-starter</artifactId>
      <version>2.2.2</version>
  </dependency>

  <!--mysql驱动-->
  <dependency>
      <groupId>com.mysql</groupId>
      <artifactId>mysql-connector-j</artifactId>
      <scope>runtime</scope>
  </dependency>
 <!--分页插件-->
  <dependency>
      <groupId>com.github.pagehelper</groupId>
      <artifactId>pagehelper-spring-boot-starter</artifactId>
      <version>1.4.1</version>
  </dependency>

看到这个，就说明安装成功了

application.propertis配置文件

html 复制代码

server.port=9090
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springapp01
spring.datasource.username=root
spring.datasource.password=123456
mybatis.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
mybatis.configuration.map-underscore-to-camel-case=true

controller

java 复制代码

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.format.annotation.DateTimeFormat;
import org.springframework.web.bind.annotation.*;

import java.time.LocalDate;
import java.util.List;

/**
 * 员工管理Controller
 */
@RestController
@Slf4j
@RequestMapping("/emps")
public class EmpController {

    @Autowired
    private EmpService empService;

    @GetMapping
    public Result page(
            String name,
            Short gender,
            @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate begin,
            @DateTimeFormat(pattern = "yyyy-MM-dd") LocalDate end,
            @RequestParam(defaultValue = "1") Integer page,
                       @RequestParam(defaultValue = "10") Integer pageSize){
        log.info("{},{}.{},{},page:{},pageSize:{}",name,gender,begin,end,page, pageSize);
        //PageBean pageBean = empService.page(page, pageSize);
        PageBean pageBean = empService.pageHelper(name,gender,begin,end,page, pageSize);
        return Result.success(pageBean);
    }
    /**
     * 批量删除员工信息
     * delete from emp where id in (1,2,3)
     */
    @DeleteMapping("/{ids}")
    public  Result delete(@PathVariable List<Integer> ids) {
        log.info("批量删除操作 {}", ids);
        empService.delete(ids);
        return Result.success();
    }
}

services

基础类

java 复制代码

/**
 * 员工管理
 */
public interface EmpService {
    PageBean page(Integer page, Integer pageSize);
    PageBean pageHelper(String name, Short gender, LocalDate begin,LocalDate end, Integer page, Integer pageSize);

    void delete(List<Integer> ids);
}

实现类

java 复制代码

package com.itheima.service.impl;

import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.time.LocalDate;
import java.util.List;

@Service
public class EmpServiceImpl implements EmpService {

    @Autowired
    private EmpMapper empMapper;

    //自己实现的page方法
    @Override
    public PageBean page(Integer page, Integer pageSize) {
        Long count = empMapper.count();
        Integer start = (page - 1) * pageSize;
        List<Emp> page1 = empMapper.page(start, pageSize);
        return new PageBean(count, page1);
    }

    @Override
    public  PageBean pageHelper(String name, Short gender, LocalDate begin, LocalDate end, Integer page, Integer pageSize){
        //设置分页参数
        PageHelper.startPage(page, pageSize);
        List<Emp> empList = empMapper.listAll(name, gender, begin,end);
        Page<Emp> p = (Page<Emp>) empList;
        return new PageBean(p.getTotal(), p.getResult());
    }

    @Override
    public void delete(List<Integer> ids){
        empMapper.delete(ids);
    }
}

mapper

xml 复制代码

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.itheima.mapper.EmpMapper">
    <select id="listAll" resultType="com.itheima.pojo.Emp">
        select * from emp
        <where>
            <if test="name != null">
                name like concat('%',#{name},'%')
            </if>
            <if test="gender != null">
                and gender = #{gender}
            </if>
            <if test="begin != null and end != null">
                and entrydate between #{begin} and #{end}
            </if>
        </where>
        order by update_time desc
    </select>

    <delete id="delete">
        delete from emp where id in
        <foreach collection="ids" item="id" open="(" close=")" separator=",">
            #{id}
        </foreach>
    </delete>
</mapper>