Java - Mybatis借助PageHelper实现分页，集成SpringBoot

未使用SpringBoot

<dependency>
 <groupId>com.github.pagehelper</groupId>
 <artifactId>pagehelper</artifactId>
 <version>5.3.1</version>
</dependency>

<plugins>
 <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
</plugins>

List<Car> selectAll();

<select id="selectAll" resultType="Car">
 select * from t_car
</select>

@Test
public void testPageHelper() throws Exception{
 SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().b
uild(Resources.getResourceAsStream("mybatis-config.xml"));
 SqlSession sqlSession = sqlSessionFactory.openSession();
 CarMapper mapper = sqlSession.getMapper(CarMapper.class);
 // 开启分?
 PageHelper.startPage(2, 2);
 // 执?查询语句
 List<Car> cars = mapper.selectAll();
 // 获取分?信息对象
 PageInfo<Car> pageInfo = new PageInfo<>(cars, 5);
 System.out.println(pageInfo);
}

执?结果：
PageInfo{pageNum=2, pageSize=2, size=2, startRow=3, endRow=4, total=6, pages=3,
list=Page{count=true, pageNum=2, pageSize=2, startRow=2, endRow=4, total=6, pages=3,
reasonable=false, pageSizeZero=false}[Car{id=86, carNum='1234', brand='丰?霸道',
guidePrice=50.5, produceTime='2020-10-11', carType='燃油?'}, Car{id=87, carNum='1234',
brand='丰?霸道', guidePrice=50.5, produceTime='2020-10-11', carType='燃油?'}], prePage=1,
nextPage=3, isFirstPage=false, isLastPage=false, hasPreviousPage=true, hasNextPage=true,
navigatePages=5, navigateFirstPage=1, navigateLastPage=3, navigatepageNums=[1, 2, 3]}

<!-- 分页插件 -->
<dependency>
 ?  <groupId>com.github.pagehelper</groupId>
 ?  <artifactId>pagehelper-spring-boot-starter</artifactId>
 ?  <version>1.2.5</version>
</dependency>

#分页插件
pagehelper.helper-dialect=mysql
pagehelper.params=count=countSql
pagehelper.reasonable=true
pagehelper.support-methods-arguments=true

创建controller层
Mapper文件中, SQL不用增加 limit分页指令,需要什么直接查就可以,Pagehelper 可以自动实现分页!

package com.ithuang.demo.controller;
?
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.service.OrderInfoService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
?
import javax.annotation.Resource;
import java.util.List;
?
@RestController
public class OrderInfoController {
?
? ? @Resource
? ? private OrderInfoService orderInfoService;
?
? ? @GetMapping("/getOrderInfoList")
? ? public List<OrderInfo> getOrderInfoList(@RequestParam(value = "pageNow",defaultValue = "1") int pageNow,
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? @RequestParam(value = "pageSize",defaultValue = "3") int pageSize){
?
? ? ? ? return orderInfoService.getOrderInfoList(pageNow,pageSize);
? ? }
}

2. 创建Service层

package com.ithuang.demo.service;
?
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.ithuang.demo.bean.OrderInfo;
import com.ithuang.demo.mapper.OrderInfoMapper;
import org.springframework.stereotype.Service;
?
import javax.annotation.Resource;
import java.util.List;
?
@Service
public class OrderInfoService {
?
? ? @Resource
? ? private OrderInfoMapper orderInfoMapper;
?
? ? public List<OrderInfo> getOrderInfoList(int pageNow, int pageSize) {
? ? ? ? PageHelper.startPage(pageNow,pageSize);
? ? ? ? List<OrderInfo> orderInfoList = orderInfoMapper.getOrderInfoList();
? ? ? ? PageInfo<OrderInfo> userPageInfo = new PageInfo<>(orderInfoList);
? ? ? ? return userPageInfo.getList();
? ? }
}

3. 创建Mapper层

package com.ithuang.demo.mapper;
?
import com.ithuang.demo.bean.OrderInfo;
import org.apache.ibatis.annotations.Mapper;
?
import java.util.List;
?
@Mapper
public interface OrderInfoMapper {
?
? ? List<OrderInfo> getOrderInfoList();
}

5. 编写xml文件?

<?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.ithuang.demo.mapper.OrderInfoMapper">
? ? <select id="getOrderInfoList" parameterType="int" resultType="com.ithuang.demo.bean.OrderInfo">
? ? ? ? SELECT * FROM order_info
? ? </select>
</mapper>