SpringBoot+Mybatis分页插件PageHelper实现分页效果

目录

• 一、项目结构
• 二、插件引入
• 三、代码
• 四、测试:

<&＃63;xml version="1.0" encoding="UTF-8"&＃63;>

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.5.6
         
    
    com.simons
    SimonsStudio
    0.0.1-SNAPSHOT
    SimonsStudio
    SimonsStudio
    
        1.8
    
    
        
            org.springframework.boot
            spring-boot-starter-web
        
        
        
            org.mybatis.spring.boot
            mybatis-spring-boot-starter
            2.2.0
        
 
        
            mysql
            mysql-connector-java
            runtime
        
        
            org.springframework.boot
            spring-boot-starter-test
            test
        
        
        
            com.github.pagehelper
            pagehelper-spring-boot-starter
            1.2.3
        
    
 
    
 
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    
 

server:
  port: 8080
 
spring:
    datasource:
        name: test
        url: jdbc:mysql://127.0.0.1:3306/simonsdb
        username: root
        password: root
        driver-class-name: com.mysql.jdbc.Driver
 
mybatis:
  mapper-locations: classpath:mapper/*.xml  #注意了！这个是mapper.xml的路径。要按照目录文件夹来命名。
  type-aliases-package: com.smions.entity  #实体类的文件夹
pagehelper: #
  helperDialect: mysql
  reasonable: true
  supportMethodsArguments: true
  params: count=countSql

package com.simons.mapper;
 
import com.simons.entity.Student;
import org.apache.ibatis.annotations.Mapper;
import org.springframework.stereotype.Component;
import java.util.List;
import java.util.Map;
 
@Mapper
@Component
public interface StudentMapper {
    /**
     * 查询全部用户
     * @return
     */
    List> selectAll();
 
    /**
     * 分页查询用户
     * @return
     */
    List selectPage();
}

<&＃63;xml version="1.0" encoding="UTF-8" &＃63;>


    
        id,
        username,
        password
    
    
        SELECT
        
        FROM student
    
 
 
    
        SELECT
        
        FROM student
    
 
 

package com.simons.service;
 
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.simons.entity.Student;
import com.simons.mapper.StudentMapper;
import com.simons.util.PageRequest;
import com.simons.util.PageResult;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
 
import java.util.List;
import java.util.Map;
 
@Service
public class StudentService{
    @Autowired
    private StudentMapper studentMapper;
 
    public List> findAll() {
//        List students =
        List>  map = studentMapper.selectAll();
        return map;
    }
 
    public PageResult findPage(PageRequest pageRequest) {
        PageInfo pageInfo = getPageInfo(pageRequest);
        PageResult pageResult = new PageResult();
        pageResult.setPageNum(pageInfo.getPageNum());
        pageResult.setPageSize(pageInfo.getPageSize());
        pageResult.setTotalPages(pageInfo.getPages());
        pageResult.setContent(pageInfo.getList());
        return pageResult;
    }
    
    /**
     * 调用分页插件完成分页
     *
     */
    public PageInfo getPageInfo(PageRequest pageRequest) {
        int pageNum = pageRequest.getPageNum();
        int pageSize = pageRequest.getPageSize();
        PageHelper.startPage(pageNum,pageSize);//核心代码:pageHelper查询分页
        List students = studentMapper.selectPage();
        PageInfo pageInfo = new PageInfo<>(students);
        return pageInfo;
    }
}

package com.simons.controller;
 
import com.simons.service.StudentService;
import com.simons.util.PageRequest;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.*;
 
import java.util.List;
import java.util.Map;
 
//@RestController
//@RequestMapping("/student")
 
@Controller
@RequestMapping(value = {"/student"})
public class StudentController {
    @Autowired
    private StudentService studentService;
    @ResponseBody
    @RequestMapping(value="/findAll")
    public List> findAll() {
        return studentService.findAll();
    }
 
    @ResponseBody
    @RequestMapping(value = {"/findPage"})
    public Object findPage(@RequestParam(name = "pageNum")String pageNum , @RequestParam(name = "pageSize") String pageSize) {
        PageRequest pageQuery = new PageRequest();
        pageQuery.setPageNum(Integer.parseInt(pageNum));
        pageQuery.setPageSize(Integer.parseInt(pageSize));
        return studentService.findPage(pageQuery);
    }
//    @PostMapping(value="/findPage")
//    public Object findPage(@RequestBody PageRequest pageQuery) {
//        return studentService.findPage(pageQuery);
//    }
}

package com.simons.util;
 
 
import java.util.List;
/**
 * 分页返回结果
 */
public class PageResult {
    /**
     * 当前页码
     */
    private int pageNum;
    /**
     * 每页数量
     */
    private int pageSize;
    /**
     * 记录总数
     */
    private long totalSize;
    /**
     * 页码总数
     */
    private int totalPages;
    /**
     * 数据模型
     */
    private List<&＃63;> content;
    public int getPageNum() {
        return pageNum;
    }
    public void setPageNum(int pageNum) {
        this.pageNum = pageNum;
    }
    public int getPageSize() {
        return pageSize;
    }
    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }
    public long getTotalSize() {
        return totalSize;
    }
    public void setTotalSize(long totalSize) {
        this.totalSize = totalSize;
    }
    public int getTotalPages() {
        return totalPages;
    }
    public void setTotalPages(int totalPages) {
        this.totalPages = totalPages;
    }
    public List<&＃63;> getContent() {
        return content;
    }
    public void setContent(List<&＃63;> content) {
        this.cOntent= content;
    }
}

package com.simons.util;
 
public class PageRequest {
    /**
     * 当前页码
     */
    private int pageNum;
    /**
     * 每页数量
     */
    private int pageSize;
 
    public int getPageNum() {
        return pageNum;
    }
    public void setPageNum(int pageNum) {
        this.pageNum = pageNum;
    }
    public int getPageSize() {
        return pageSize;
    }
    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }
}

package com.simons;
 
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ComponentScan;
 
@SpringBootApplication
@MapperScan("com.simons.mapper")
//@ComponentScan(basePackages={"com.simons.*"})
public class SimonsStudioApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(SimonsStudioApplication.class, args);
    }
 
}