SSM中使用Mybatis的PageHelper插件实现分页

你的名字 2023-10-18 12:52 1阅读 0赞

### 效果 ###

![20181220113848711.gif][]![Image 1][]

## 实现 ##

前言

前面实现SSM整合以及实现原始手动分页参考

[https://blog.csdn.net/BADAO\_LIUMANG\_QIZHI/article/details/85113289][https_blog.csdn.net_BADAO_LIUMANG_QIZHI_article_details_85113289]

### 添加jar包 ###

使用插件首先要先加载jar包

![Image 1][]![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBREFPX0xJVU1BTkdfUUlaSEk_size_16_color_FFFFFF_t_70][]

jar包下载：

[https://download.csdn.net/download/badao\_liumang\_qizhi/10863649][https_download.csdn.net_download_badao_liumang_qizhi_10863649]

将两个jar包，放到项目下的lib目录下。

### 修改applicationContext.xml ###

在sqlsession下增加

完整代码

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:aop="http://www.springframework.org/schema/aop"
     xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
     xmlns:context="http://www.springframework.org/schema/context"
     xmlns:mvc="http://www.springframework.org/schema/mvc"
     xsi:schemaLocation="
         http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
         http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
         http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc-3.0.xsd
         http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
         http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-3.0.xsd
         http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">
     
     
    
    
       <context:annotation-config />
       <context:component-scan base-package="com.badao.service" />
    
     <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 
       <property name="driverClassName"> 
           <value>com.mysql.jdbc.Driver</value> 
       </property> 
       <property name="url"> 
           <value>jdbc:mysql://localhost:3306/ssmtest?characterEncoding=UTF-8</value> 
       </property> 
       <property name="username"> 
           <value>root</value> 
       </property> 
       <property name="password"> 
           <value>523627</value> 
       </property>   
     </bean>
     
     
     <bean id="sqlSession" class="org.mybatis.spring.SqlSessionFactoryBean">
      <property name="typeAliasesPackage" value="com.badao.pojo" />
      <property name="dataSource" ref="dataSource"/>
      <property name="mapperLocations" value="classpath:com/badao/mapper/*.xml"/>
      <property name="plugins">
                <array>
                  <bean class="com.github.pagehelper.PageInterceptor">
                    <property name="properties">
                      
                      <value>
                      </value>
                    </property>
                  </bean>
                </array>
              </property>  
     </bean>
    
     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
      <property name="basePackage" value="com.badao.mapper"/>
     </bean>
    
    
    
    </beans>

### 修改service ###

Service中去掉total方法和原来手动分页的方法

package com.badao.service;
    
    import java.util.List;
    
    import com.badao.pojo.User;
    import com.badao.util.Page;
    
    public interface UserService {
     List<User> selectAllUser();
     //List<User> selectAllUser(Page page);
     //int total();
    
    }

### 修改serviceImpl ###

注释掉原来的手动分页方法

package com.badao.service.impl;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Service;
    
    import com.badao.mapper.UserMapper;
    import com.badao.pojo.User;
    import com.badao.service.UserService;
    import com.badao.util.Page;
    @Service
    public class UserServiceImpl implements UserService {
    
     @Autowired
     UserMapper userMapper;
     public List<User> selectAllUser() {
      // TODO Auto-generated method stub
      return userMapper.selectAllUser();
     }
    /* @Override
     public List<User> selectAllUser(Page page) {
      // TODO Auto-generated method stub
      return userMapper.selectAllUser(page);
     }
     @Override
     public int total() {
      // TODO Auto-generated method stub
      return userMapper.total();
     }*/
    
    }

###    修改mapper ###

userMapper.java中注释掉total()方法以及原来的手动分页的方法。

package com.badao.mapper;
    
    import java.util.List;
    import com.badao.pojo.User;
    import com.badao.util.Page;
    
    
    
    public interface UserMapper {
     public int addUser(User user);
     public User selectUser(int id);
     public int updateUser(User user);
     public void deleteUser(int id);
     public List<User> selectAllUser();
     //public List<User> selectAllUser(Page page);
     //public int total();
     
    }

userMapper.xml中去掉total的select语句以及原来的limit语句

<?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.badao.mapper.UserMapper">
            <insert id="addUser" parameterType="User" >
                insert into user ( name,age ) values (#{name},#{age})  
            </insert>
            
            <delete id="deleteUser" parameterType="_int" >
                delete from user where id= #{id} 
            </delete>
            
            <select id="selectUser" parameterType="_int" resultType="User">
                select * from   user  where id= #{id}  
            </select>
     
            <update id="updateUser" parameterType="User" >< BR>           updateusersetname=#{name},age=#{age} where id=#{id}  
            </update>
            <select id="selectAllUser" resultType="User">
                select * from   user    <BR>           
            </select>
            
        </mapper>

### 修改Controller ###

通过

import com.github.pagehelper.PageHelper;
    import com.github.pagehelper.PageInfo;

导入类

通过

PageHelper.offsetPage(page.getStart(),5);

实现分页按需查询

通过

int total = (int) new PageInfo<>(cs).getTotal();

获取查询的总数

完整代码

package com.badao.controller;
    
    import java.util.List;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.servlet.ModelAndView;
    
    import com.badao.pojo.User;
    import com.badao.service.UserService;
    import com.badao.util.Page;
    import com.github.pagehelper.PageHelper;
    import com.github.pagehelper.PageInfo;
    
    
    
    // 告诉spring mvc这是一个控制器类
    @Controller
    @RequestMapping("")
    public class UserController {
     @Autowired
     UserService userService;
    
     @RequestMapping("listUser")
     public ModelAndView listUser(Page page){
      ModelAndView mav = new ModelAndView();
      //根据分页对象，进行查询获取查询对象集合
      //List<User> cs= userService.selectAllUser(page);
      //int total = userService.total();
      //根据总数，计算最后一页的信息
      
       PageHelper.offsetPage(page.getStart(),5);
          List<User> cs= userService.selectAllUser();
          int total = (int) new PageInfo<>(cs).getTotal();
          page.caculateLast(total);
      // 放入转发参数
      mav.addObject("userList", cs);
      // 放入jsp路径
      mav.setViewName("listUser");
      return mav;
     }
    
    }

### 修改测试类 ###

注释掉原来的的手动分页实现时的单元测试代码

package com.badao.test;
    
    import java.util.List;
    
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.test.annotation.Rollback;
    import org.springframework.test.context.ContextConfiguration;
    import com.badao.mapper.UserMapper;
    import com.badao.pojo.User;
    import com.badao.util.Page;
    import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;//使用junit4时报错导这个包
    @RunWith(SpringJUnit4ClassRunner.class)//使用junit4进行测试
    @ContextConfiguration("classpath:applicationContext.xml")//加载配置文件
    public class InsertTest {
     @Autowired//自动注入
     private UserMapper userMapper;
      @Test//标明是测试方法
      @Rollback(false)  //标明使用完此方法后事务不回滚,true时为回滚
      public void testAdd() {
             for (int i = 0; i < 100; i++) {
              User user = new User();
              user.setName("user"+i);
                 userMapper.addUser(user);
             }
     
         }
         
       /*  @Test
         public void testTotal() {
             int total = userMapper.total();
             System.out.println(total);
         }
     
         @Test
         public void testList() {
             Page p = new Page();
             p.setStart(2);
             p.setCount(3);
             List<User> cs=userMapper.selectAllUser(p);
             for (User c : cs) {
                 System.out.println(c.getName());
             }
         }*/
    }

### jsp页面代码 ###

保持不变

<%@ page language="java" contentType="text/html; charset=UTF-8"
        pageEncoding="UTF-8" import="java.util.*"%>
     
    <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
    
    <%
     pageContext.setAttribute("APP_PATH", request.getContextPath());
    %>
    <!DOCTYPE html>
    <html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>查询所有用户</title>
    </head>
    
    <script type="text/javascript" src="${APP_PATH }/static/js/jquery-1.12.4.min.js"></script>
    <link href="${APP_PATH }/static/bootstrap-3.3.7-dist/css/bootstrap.min.css" rel="stylesheet">
    <script src="${APP_PATH }/static/bootstrap-3.3.7-dist/js/bootstrap.min.js"></script>
    <body>
    <table align='center' border='1' cellspacing='0' class="table table-bordered"
        <th >
            <td>id</td>
            <td>name</td>
            <td>age</td>
        </th>
        <c:forEach items="${userList}" var="u">
            <tr class="active">
                <td >${u.id}</td>
                <td>${u.name}</td>
                <td>${u.age}</td>
                  
            </tr>
        </c:forEach>
    </table>
    <div style="text-align:center">
            <a href="?start=0">首  页</a>
            <a href="?start=${page.start-page.count}">上一页</a>
            <a href="?start=${page.start+page.count}">下一页</a>
            <a href="?start=${page.last}">末  页</a>
    </div>
      </body>
    </html>

### 源码下载 ###

[https://download.csdn.net/download/badao\_liumang\_qizhi/10863821][https_download.csdn.net_download_badao_liumang_qizhi_10863821]

###     ###

[20181220113848711.gif]: https://img-blog.csdnimg.cn/20181220113848711.gif
[Image 1]: 
[https_blog.csdn.net_BADAO_LIUMANG_QIZHI_article_details_85113289]: https://blog.csdn.net/BADAO_LIUMANG_QIZHI/article/details/85113289
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBREFPX0xJVU1BTkdfUUlaSEk_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20181220113907557.jpg?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L0JBREFPX0xJVU1BTkdfUUlaSEk=,size_16,color_FFFFFF,t_70
[https_download.csdn.net_download_badao_liumang_qizhi_10863649]: https://download.csdn.net/download/badao_liumang_qizhi/10863649
[https_download.csdn.net_download_badao_liumang_qizhi_10863821]: https://download.csdn.net/download/badao_liumang_qizhi/10863821