Spring Boot 集成 PageHelper

配置一：在 【pom.xml】 文件中引入依赖

<!-- mybatis的分页插件 -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper-spring-boot-starter</artifactId>
    <version>1.2.10</version>
</dependency>

配置二：在 【application.properties】 文件中配置 pagehelper

pagehelper.helperDialect=mysql
pagehelper.reasonable=true
pagehelper.supportMethodsArguments=true
pagehelper.params=count=countSql

使用示例：

package com.huang.pims.family.controller;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.huang.pims.family.model.FamilyMember;
import com.huang.pims.family.service.FamilyMemberService;
import com.huang.pims.family.vo.FamilyMemberVO;
import org.apache.ibatis.session.RowBounds;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.*;

import java.util.List;

/**
 * (FamilyMember)表控制层
 *
 * @author huangj
 * @since 2019-06-09 17:28:50
 */
@RestController
@RequestMapping("/familyMember")
public class FamilyMemberController {

    private static final Logger LOGGER = LoggerFactory.getLogger(FamilyMemberController.class);

    /**
     * 服务对象
     */
    @Autowired
    private FamilyMemberService familyMemberService;
　　　　

    // offset代表页码，limit代表每页记录数
    @RequestMapping(value = "/queryListForPageHelper", method = RequestMethod.POST)
    public ResponseEntity queryListForPageHelper(@RequestParam int offset, @RequestParam int limit) {
        LOGGER.info("rowBounds.offset={}, rowBounds.limit={}", offset, limit);
        PageHelper.startPage(offset, limit);
        List<FamilyMemberVO> familyMemberVOList = familyMemberService.queryListForPage(null);
        return new ResponseEntity(new PageInfo<>(familyMemberVOList), HttpStatus.OK);
    }

}

测试

后端控制台输出

Creating a new SqlSession
SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@5c28a370] was not registered for synchronization because synchronization is not active
JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@4ea4e9c2] will not be managed by Spring
==>  Preparing: SELECT count(0) FROM base_family_member WHERE status = 1
==> Parameters:
<==    Columns: count(0)
<==        Row: 3
<==      Total: 1
==>  Preparing: select id, member_name, nick_name, status, created_by, created_at, modified_by, modified_at from base_family_member where status = 1 LIMIT ?
==> Parameters: 2(Integer)
<==    Columns: id, member_name, nick_name, status, created_by, created_at, modified_by, modified_at
<==        Row: 1, 黄一号, 老爸, 1, null, 2019-05-03 18:55:36, null, 2019-05-03 18:55:36
<==        Row: 2, 黄二号, 老妈, 1, null, 2019-05-03 00:23:05, null, 2019-05-03 00:23:05
<==      Total: 2
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@5c28a370]

　　从上述输出内容可以看出，在执行查询sql之前，会先查询一次记录总数。然后通过记录总数，查询记录的页码，每页的最大记录数，为查询sql添加limit限制，从而达到分页的效果。上述的请求是每页展示2条记录，其中第一页的所有记录。如果请求的页数操过了总页数，则查询的结果始终是分页后的最后一页的记录。

　　PageHelper插件会将【PageHelper.startPage(offset, limit);】之后跟随的一次查询进行分页查询，后续如果还有查询，则不会再分页辅助，除非在查询之前再添加【PageHelper.startPage(offset, limit);】。