如何在springboot中使用PageHelper分页插件

文章目录

- - - - 1. pom依赖
      - 2. yml
      - 3. 实体类
      - 4. mapper映射文件
      - 4. mapper接口
      - 5. service接口
      - 6. 实现类
      - 7. controller
      - 8. 浏览器验证

使用思路：
1.引入myabtis和pagehelper依赖
2.yml中配置mybatis扫描和实体类
3. 这2行代码
pageNum：当前第几页
pageNum：显示多少条数据
userList：数据库查询的数据数据列表PageHelper.startPage(pageNum, pageSize);PageInfo pageInfo = new PageInfo(userList);最后返回一个pageInfo 对象即可，pageInfo 这个对象中只有数据一些信息，但是，没有成功失败的状态或者提示语。真实企业中会封装一个返回对象，把pageInfo 放到对象中

1. pom依赖

<!--Myabtis依赖--><dependency><groupId>org.mybatis.spring.boot</groupId><artifactId>mybatis-spring-boot-starter</artifactId><version>2.1.2</version></dependency><!--pagehelper依赖--><dependency><groupId>com.github.pagehelper</groupId><artifactId>pagehelper-spring-boot-starter</artifactId><version>1.2.13</version></dependency><!--mysql依赖--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.20</version></dependency><!--数据源--><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.21</version></dependency><!--提高效率lombok插件--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><optional>true</optional></dependency>

2. yml

spring:application:name: springboot-vuedatasource:type: com.alibaba.druid.pool.DruidDataSourcedriver-class-name: com.mysql.cj.jdbc.Driverurl: jdbc:mysql://127.0.0.1:3306/vue?characterEncoding=UTF-8&serverTimezone=GMT%2B8username: rootpassword: rootserver:port: 8989servlet:context-path: /vue#mybatis配置信息
mybatis:configuration:map-underscore-to-camel-case: true#控制台日志配置 打印sqllog-impl: org.apache.ibatis.logging.stdout.StdOutImplmapper-locations: classpath:mappers/*.xmltype-aliases-package: com.baizhi.entity#数据库方言
pagehelper:helper-dialect: mysql#控制台日志配置
logging:pattern:console: "[%thread] %-5level %logger{36} - %msg%n"

3. 实体类

package com.baizhi.entity;import com.fasterxml.jackson.annotation.JsonFormat;
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.ToString;
import lombok.experimental.Accessors;import java.io.Serializable;@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
@Accessors(chain = true)
public class TUser implements Serializable {private static final long serialVersionUID = 745741804375055500L;private Integer id;private String name;private Integer age;@JsonFormat(pattern = "yyyy-MM-dd", timezone = "GTM+8")private String bir;
}

4. mapper映射文件

<?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.baizhi.dao.TUserDao"><resultMap type="com.baizhi.entity.TUser" id="TUserMap"><result property="id" column="id" jdbcType="INTEGER"/><result property="name" column="name" jdbcType="VARCHAR"/><result property="age" column="age" jdbcType="INTEGER"/><result property="bir" column="bir" jdbcType="VARCHAR"/></resultMap><select id="selectUserAll"  resultMap="TUserMap">selectid, name, age, birfrom vue.t_user</select>
</mapper>

4. mapper接口

package com.baizhi.dao;import com.baizhi.entity.TUser;
import org.apache.ibatis.annotations.Mapper;
import java.util.List;/*** (TUser)表数据库访问层** @author makejava* @since 2020-05-05 18:39:21*/
@Mapper
public interface TUserDao {List<TUser> selectUserAll();
}

5. service接口

package com.baizhi.service;import com.baizhi.entity.TUser;
import com.github.pagehelper.PageInfo;import java.util.List;/*** (TUser)表服务接口** @author makejava* @since 2020-05-05 18:39:22*/
public interface TUserService {PageInfo list(Integer pageNum, Integer pageSize);
}

6. 实现类

package com.baizhi.service.impl;import com.baizhi.dao.TUserDao;
import com.baizhi.entity.TUser;
import com.baizhi.service.TUserService;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import org.springframework.stereotype.Service;import javax.annotation.Resource;
import java.util.List;/*** (TUser)表服务实现类** @author makejava* @since 2020-05-05 18:39:22*/
@Service("tUserService")
public class TUserServiceImpl implements TUserService {@Resourceprivate TUserDao tUserDao;public PageInfo list(Integer pageNum, Integer pageSize) {PageHelper.startPage(pageNum, pageSize);List<TUser> userList = this.tUserDao.selectUserAll();//如果返回前的数据 和 数据库实体 对象数据一致 采下面方式//如果不一致，采用 PageInfo pageInfo = new PageInfo(); pageInfo.setList(shippingList);PageInfo pageInfo = new PageInfo(userList);return pageInfo;}
}

7. controller

package com.baizhi.controller;import com.baizhi.service.TUserService;
import com.github.pagehelper.PageInfo;
import org.springframework.web.bind.annotation.*;import javax.annotation.Resource;/*** (TUser)表控制层** @author makejava* @since 2020-05-05 18:39:22*/
@RestController
@CrossOrigin
@RequestMapping("user")
public class TUserController {/*** 服务对象*/@Resourceprivate TUserService tUserService;@GetMapping("findAll")public PageInfo findAll(@RequestParam(required = false, defaultValue = "1") Integer pageNum,@RequestParam(required = false, defaultValue = "10") Integer pageSize) {PageInfo list = this.tUserService.list(pageNum, pageSize);return list;}
}