將分頁所需的內容都放到一個實體類別中
分頁資料所需的實體類別！內包含頁碼，頁大小，總條數，總頁數，起始行
pagehelpr提供了這個類別pageInfo，不需要我們自己創建
select * from 表名limit 起始行，展示幾個資料
#第n頁每頁展示五條資料
select * from 表名limit ( n-1)*5,5
#每頁顯示多少個 pageSize
#3
#總共有多少條
total
select count（*） from 表名
#總頁數
pages
pages=total%pagesSize==0?total/pgeSize:total/pageSize 1 ;
#目前頁
pageNum
1.引入pagehelper依賴
<dependency>
<groupId>com.github.pagehelper</groupId>
<artifactId>pagehelper-spring-boot-starter</artifactId>
<version>1.2.5</version>
</dependency>#pagehelper分页插件配置 pagehelper.helper-dialect=mysql pagehelper.reasonable=true pagehelper.support-methods-arguments=true pagehelper.params=count=countSql
2.bean實體類別
使用者實體：
package com.qianfeng.bean;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class Register {
private Integer id;
private String userName;
private String passWord;
private String rePassWord;
private String idCard;
private String gender;
}傳回前端的實體類別：包含查到的資料和分頁資料
package com.qianfeng.bean;
import com.github.pagehelper.PageInfo;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
import java.util.List;
@Data
@ToString
@AllArgsConstructor
@NoArgsConstructor
public class RegPage {
private PageInfo pageInfo;
private List<Register> registers;
}2.mapper層：
package com.qianfeng.mapper;
import com.qianfeng.bean.Register;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;
@Mapper
public interface PageDao {
List<Register> getAll(Integer startRow,Integer pageSize);
long getCount();
}3.service層：
package com.qianfeng.service;
import com.github.pagehelper.PageInfo;
import com.qianfeng.bean.RegPage;
public interface RegService {
RegPage getAll(PageInfo pageInfo);
}4.serviceImpl：
package com.qianfeng.service.serviceImpl;
import com.github.pagehelper.PageInfo;
import com.qianfeng.bean.RegPage;
import com.qianfeng.bean.Register;
import com.qianfeng.mapper.PageDao;
import com.qianfeng.service.RegService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;
@Service
public class RegServiceImpl implements RegService {
@Autowired
private PageDao pageDao;
@Override
public RegPage getAll(PageInfo pageInfo) {
List<Register> all = pageDao.getAll(pageInfo.getStartRow(), pageInfo.getPageSize());//分页后的数据
long count = pageDao.getCount();//总记录条数
pageInfo.setTotal(count);
//总页数
int pages= (int) (pageInfo.getTotal()%pageInfo.getPageSize()==0?pageInfo.getTotal()/pageInfo.getPageSize():pageInfo.getTotal()/pageInfo.getPageSize()+1);
pageInfo.setPages(pages);
RegPage regPage = new RegPage();
regPage.setPageInfo(pageInfo);
regPage.setRegisters(all);
return regPage;
}
}5.handler層：
package com.qianfeng.handler;
import com.github.pagehelper.PageInfo;
import com.qianfeng.bean.RegPage;
import com.qianfeng.service.RegService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class RegHandler {
@Autowired
private RegService regService;
@RequestMapping("/page/{pageNum}")
public RegPage regPage(@PathVariable("pageNum") Integer pageNum){
System.out.println(".........");
PageInfo pageInfo = new PageInfo();
pageInfo.setPageNum(pageNum);
pageInfo.setPageSize(3);
pageInfo.setStartRow((pageNum-1)*pageInfo.getPageSize());
System.out.println("startRow" + pageInfo.getStartRow());
return regService.getAll(pageInfo);
}
}6.mapper.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.qianfeng.mapper.PageDao">
<select id="getAll" resultType="com.qianfeng.bean.Register">
select * from m_register limit #{startRow},#{pageSize}
</select>
<select id="getCount" resultType="java.lang.Long">
select count(*) from m_register
</select>
</mapper>7. application.yaml
spring:
datasource:
url: jdbc:mysql:///map?serverTimezone=Asia/Shanghai&useSSL=false
username: root
password: 123
driver-class-name: com.mysql.jdbc.Driver
druid:
aop-patterns: com.qianfeng.* #监控SpringBean
filters: stat,wall # 底层开启功能，stat（sql监控），wall（防火墙）
stat-view-servlet: # 配置监控页功能
enabled: true
login-username: admin
login-password: admin
resetEnable: false
web-stat-filter: # 监控web
enabled: true
urlPattern: /*
exclusions: '*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*'
filter:
stat: # 对上面filters里面的stat的详细配置
slow-sql-millis: 1000
logSlowSql: true
enabled: true
wall:
enabled: true
config:
drop-table-allow: false
mvc:
pathmatch:
matching-strategy: ant_path_matcher
# mybatis的配置规则
mybatis:
#config-location: classpath:mapper/mybatis-config.xml
mapper-locations: classpath:mapper/*
configuration:
log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
# static-locations: [classpath:/haha/] # 静态资源路径自定义8.application,properties
spring.main.allow-circular-references=true spring.thymeleaf.prefix=classpath:/templates/ spring.thymeleaf.suffix=.html pagehelper.helper-dialect=mysql pagehelper.reasonable=true pagehelper.support-methods-arguments=true pagehelper.params=count=countSql
關於PageInfo這個類，原始碼如下：
public class PageInfo implements Serializable {
private static final long serialVersionUID = 1L;
//当前页
private int pageNum;
//每页的数量
private int pageSize;
//当前页的数量
private int size;
//由于startRow 和endRow 不常用，这里说个具体的用法
//可以在页面中"显示startRow 到endRow 共size 条数据"
//当前页面第一个元素在数据库中的行号
private int startRow;
//当前页面最后一个元素在数据库中的行号
private int endRow;
//总记录数
private long total;
//总页数
private int pages;
//结果集
private List list;
//前一页
private int prePage;
//下一页
private int nextPage;
//是否为第一页
private boolean isFirstPage = false;
//是否为最后一页
private boolean isLastPage = false;
//是否有前一页
private boolean hasPreviousPage = false;
//是否有下一页
private boolean hasNextPage = false;
//导航页码数
private int navigatePages;
//所有导航页号
private int[] navigatepageNums;
//导航条上的第一页
private int navigateFirstPage;
//导航条上的最后一页
private int navigateLastPage;
}目錄結構：
以上是PageHelper在springboot+mybatis框架中如何使用的詳細內容。更多資訊請關注PHP中文網其他相關文章！
