很长一段时间里，我学习编程很少总结代码。后来代码总结也只是写在一个电脑里的文件夹，觉得与互联网脱轨了，哈哈哈，所以现在也准备写一写博客，记录自己，提高水平。
这是我的第一篇，也是关于SSM框架下使用PageHelper。
这里不具体写我做的项目课题的全部内容，主要专注于PageHelper部分
工程结构如下图：
首先在pom.xml（parking_dao模块下）引入PageHelper依赖
1 <?xml version="1.0" encoding="UTF-8"?>
2 <project xmlns="http://maven.apache.org/POM/4.0.0"
3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
5 <parent>
6 <artifactId>parking</artifactId>
7 <groupId>com.dong</groupId>
8 <version>1.0-SNAPSHOT</version>
9 </parent>
10 <modelVersion>4.0.0</modelVersion>
11
12 <artifactId>parking_dao</artifactId>
13 <dependencies>
14 <dependency>
15 <groupId>mysql</groupId>
16 <artifactId>mysql-connector-java</artifactId>
17 <version>5.1.47</version>
18 </dependency>
19 <dependency>
20 <groupId>org.mybatis</groupId>
21 <artifactId>mybatis</artifactId>
22 <version>3.4.6</version>
23 </dependency>
24
25 <dependency>
26 <groupId>org.springframework</groupId>
27 <artifactId>spring-core</artifactId>
28 <version>${spring.version}</version>
29 </dependency>
30 <dependency>
31 <groupId>org.springframework</groupId>
32 <artifactId>spring-context</artifactId>
33 <version>${spring.version}</version>
34 </dependency>
35 <dependency>
36 <groupId>org.springframework</groupId>
37 <artifactId>spring-beans</artifactId>
38 <version>${spring.version}</version>
39 </dependency>
40 <dependency>
41 <groupId>org.mybatis</groupId>
42 <artifactId>mybatis-spring</artifactId>
43 <version>1.3.1</version>
44 </dependency>
45 <dependency>
46 <groupId>org.springframework</groupId>
47 <artifactId>spring-jdbc</artifactId>
48 <version>${spring.version}</version>
49 </dependency>
50 <dependency>
51 <groupId>com.github.pagehelper</groupId>
52 <artifactId>pagehelper</artifactId>
53 <version>5.1.2</version>
54 </dependency>
55 </dependencies>
56
57 </project>
最主要的是：
<dependency> <groupId>com.github.pagehelper</groupId> <artifactId>pagehelper</artifactId> <version>5.1.2</version></dependency>随后需要在spring配置（spring-dao）文件里配置PageHelper
1 <beans xmlns="http://www.springframework.org/schema/beans" 2 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xmlns:context="http://www.springframework.org/schema/context" 4 xsi:schemaLocation="http://www.springframework.org/schema/beans 5 http://www.springframework.org/schema/beans/spring-beans.xsd 6 http://www.springframework.org/schema/context 7 http://www.springframework.org/schema/context/spring-context.xsd"> 8 9 <context:component-scan base-package="com.dong.parking.dao"/> 10 11 <bean id="dataSource" class="org.springframework.jdbc.datasource.DriverManagerDataSource"> 12 <property name="driverClassName" value="com.mysql.jdbc.Driver"/> 13 <property name="url" 14 value="jdbc:mysql://localhost:3306/car_park?useUnicode=true&characterEncoding=utf-8&useSSL=false"/> 15 <property name="username" value="root"/> 16 <property name="password" value="root"/> 17 </bean> 18 19 <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> 20 <property name="typeAliasesPackage" value="com.dong.parking.entity"/> 21 <property name="dataSource" ref="dataSource"/> 22 <!--配置PageHelper--> 23 <property name="plugins"> 24 <array> 25 <bean class="com.github.pagehelper.PageInterceptor"> 26 <property name="properties"> 27 <value> 28 offsetAsPageNum=true 29 rowBoundsWithCount=true 30 pageSizeZero=true 31 reasonable=true 32 </value> 33 </property> 34 </bean> 35 </array> 36 </property> 37 </bean> 38 <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> 39 <property name="sqlSessionFactoryBeanName" value="sessionFactory"/> 40 <property name="basePackage" value="com.dong.parking.dao"/> 41 </bean> 42 </beans>
最主要的为：
1 <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> 2 <property name="typeAliasesPackage" value="com.dong.parking.entity"/> 3 <property name="dataSource" ref="dataSource"/> 4 <!--配置PageHelper--> 5 <property name="plugins"> 6 <array> 7 <bean class="com.github.pagehelper.PageInterceptor"> 8 <property name="properties"> 9 <value> 10 offsetAsPageNum=true 11 rowBoundsWithCount=true 12 pageSizeZero=true 13 reasonable=true 14 </value> 15 </property> 16 </bean> 17 </array> 18 </property> 19 </bean>
Ok，关于配置已经好了，现在进入parking，结构如下，以红框标识的为例
ParkSpaceController代码如下
1 package com.dong.parking.controller;
2
3 import com.dong.parking.biz.ParkSpaceBiz;
4 import com.dong.parking.entity.ParkSpace;
5 import com.dong.parking.entity.User;
6 import com.dong.parking.global.Constant;
7 import com.github.pagehelper.Page;
8 import com.github.pagehelper.PageHelper;
9 import com.github.pagehelper.PageInfo;
10 import org.springframework.beans.factory.annotation.Autowired;
11 import org.springframework.stereotype.Controller;
12 import org.springframework.web.bind.annotation.RequestMapping;
13 import org.springframework.web.bind.annotation.RequestParam;
14
15 import javax.servlet.http.HttpSession;
16 import java.util.List;
17 import java.util.Map;
18
19 @Controller("parkSpaceController")
20 @RequestMapping("/parkSpace")
21 public class ParkSpaceController {
22 @Autowired
23 private ParkSpaceBiz parkSpaceBiz;
24
25 @RequestMapping(value = "/list")
26 public String list(Map<String, Object> map, @RequestParam(value = "status", required = false) Integer status,
27 @RequestParam(defaultValue = "1", required = true, value = "pageNo") Integer pageNo) {
28 List<ParkSpace> list = null;
29 Integer pageSize = 2;
30 PageHelper.startPage(pageNo, pageSize);
31 if (status == null)
32 list = parkSpaceBiz.findAll();
33 else
34 list = parkSpaceBiz.findByStatus(status);
35
36
37 PageInfo<ParkSpace> pageInfo = new PageInfo<ParkSpace>(list);
38 map.put("pageInfo", pageInfo);
39 return "park_space_list";
40 }
41
42 @RequestMapping("/to_update")
43 public String toUpdate(Map<String, Object> map, @RequestParam int id) {
44 map.put("floor", Constant.getFloor());
45 map.put("area", Constant.getArea());
46 map.put("parkSpace", parkSpaceBiz.findById(id));
47 return "park_space_update";
48 }
49
50 @RequestMapping("/update")
51 public String update(ParkSpace parkSpace, HttpSession session) {
52 User user = (User) session.getAttribute("user");
53 parkSpace.setUpdateBy(user.getSn());
54 parkSpaceBiz.edit(parkSpace);
55 return "redirect:list";
56 }
57
58
59 @RequestMapping("/to_add")
60 public String toAdd(Map<String, Object> map) {
61 map.put("floor", Constant.getFloor());
62 map.put("area", Constant.getArea());
63 map.put("parkSpace", new ParkSpace());
64 return "park_space_add";
65 }
66
67 @RequestMapping("/add")
68 public String add(ParkSpace parkSpace, HttpSession session) {
69 User user = (User) session.getAttribute("user");
70 parkSpace.setCreateBy(user.getSn());
71 parkSpace.setUpdateBy(user.getSn());
72 parkSpaceBiz.add(parkSpace);
73 return "redirect:list";
74 }
75
76
77 @RequestMapping(value = "/remove", params = "id")
78 public String remove(int id) {
79 parkSpaceBiz.remove(id);
80 return "redirect:list";
81 }
82 }
我们关注一下list方法
1 @RequestMapping(value = "/list")
2 public String list(Map<String, Object> map, @RequestParam(value = "status", required = false) Integer status,
3 @RequestParam(defaultValue = "1", required = true, value = "pageNo") Integer pageNo) {
4 List<ParkSpace> list = null;
5 Integer pageSize = 2;
6 PageHelper.startPage(pageNo, pageSize);
7 if (status == null)
8 list = parkSpaceBiz.findAll();
9 else
10 list = parkSpaceBiz.findByStatus(status);
11
12
13 PageInfo<ParkSpace> pageInfo = new PageInfo<ParkSpace>(list);
14 map.put("pageInfo", pageInfo);
15 return "park_space_list";
16 }
这里的形参pageNo为前台传来的值。这里的步骤可归结如下
步骤1：PageHelper.startPage(pageNo,pageSize)，设置每页显示的个数和页数
步骤2：List<Bean> list = beanService.find(),获得bean的结合(这里以Bean代表一般的实体类)
步骤3：PageInfo<Bean> pageInfo = new PageInfo<Bean>(list); 将list集合封装到pageInfo对象。
步骤4：map.put("pageInfo",pageInfo);将pageInfo对象回给前台
好了，现在咱们来到前台页面，park_space_list.jsp代码如下
1 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
2 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
3
4 <jsp:include page="top.jsp"/>
5
6 <section id="content" class="table-layout animated fadeIn">
7 <div class="tray tray-center">
8 <div class="content-header">
9 <h2> 员工列表 </h2>
10 <p class="lead"></p>
11 </div>
12 <div class="admin-form theme-primary mw1000 center-block" style="padding-bottom: 175px;">
13 <div class="panel heading-border">
14 <div class="panel-menu">
15 <div class="row">
16 <div class="hidden-xs hidden-sm col-md-3">
17 <div class="btn-group">
18 <button type="button" class="btn btn-default light">
19 <i class="fa fa-refresh"></i>
20 </button>
21 <button type="button" class="btn btn-default light">
22 <i class="fa fa-trash"></i>
23 </button>
24 <button type="button" class="btn btn-default light">
25 <i class="fa fa-plus"
26 onclick="javascript:window.location.href=‘/parkSpace/to_add‘;"></i>
27 </button>
28 </div>
29 </div>
30 <div class="col-xs-12 col-md-9 text-right">
31 <div class="btn-group">
32 <button type="button" class="btn btn-default light">
33 <i class="fa fa-chevron-left"></i>
34 </button>
35
36 <button type="button" class="btn btn-default light">
37 <i class="fa fa-chevron-right"></i>
38 </button>
39 </div>
40 </div>
41 </div>
42 </div>
43 <div class="panel-body pn">
44 <table id="message-table" class="table admin-form theme-warning tc-checkbox-1">
45 <thead>
46 <tr class="">
47 <th class="text-center hidden-xs">Select</th>
48 <th class="hidden-xs">楼层</th>
49 <th class="hidden-xs">区域</th>
50 <th class="hidden-xs">车位号</th>
51 <th class="hidden-xs">状态</th>
52
53 <th>操作</th>
54 </tr>
55 </thead>
56 <tbody>
57 <c:forEach items="${pageInfo.list}" var="space">
58 <tr class="message-unread">
59 <td class="hidden-xs">
60 <label class="option block mn">
61 <input type="checkbox" name="mobileos" value="FR">
62 <span class="checkbox mn"></span>
63 </label>
64 </td>
65 <td>${space.floor}</td>
66 <td>${space.area}</td>
67 <td>${space.spaceId}</td>
68 <td>
69 <c:if test="${space.status == 0}">空闲</c:if>
70 <c:if test="${space.status == 1}">占用</c:if>
71 <c:if test="${space.status == 2}">预定</c:if>
72 </td>
73
74 <td>
75 <a href="/parkSpace/to_update?id=${space.id}">编辑</a>
76 <a href="/parkSpace/remove?id=${space.id}">删除</a>
77 </td>
78 </tr>
79 </c:forEach>
80 </tbody>
81 </table>
82 <p>当前 ${pageInfo.pageNum }页,总${pageInfo.pages }
83 页,总 ${pageInfo.total } 条记录
84 </p>
85 <a href="list?pageNo=${pageInfo.getFirstPage()}">首页</a>
86 <c:if test="${pageInfo.hasPreviousPage }">
87 <a href="list?pageNo=${pageInfo.pageNum-1}">上一页</a>
88 </c:if>
89
90 <c:if test="${pageInfo.hasNextPage }">
91 <a href="list?pageNo=${pageInfo.pageNum+1}">下一页</a>
92 </c:if>
93
94 <a href="list?pageNo=${pageInfo.getLastPage()}">末页</a>
95 </div>
96 </div>
97 </div>
98 </div>
99 </section>
100
101 <jsp:include page="bottom.jsp"/>
我们关注于
1 <div class="panel-body pn">
2 <table id="message-table" class="table admin-form theme-warning tc-checkbox-1">
3 <thead>
4 <tr class="">
5 <th class="text-center hidden-xs">Select</th>
6 <th class="hidden-xs">楼层</th>
7 <th class="hidden-xs">区域</th>
8 <th class="hidden-xs">车位号</th>
9 <th class="hidden-xs">状态</th>
10
11 <th>操作</th>
12 </tr>
13 </thead>
14 <tbody>
15 <c:forEach items="${pageInfo.list}" var="space">
16 <tr class="message-unread">
17 <td class="hidden-xs">
18 <label class="option block mn">
19 <input type="checkbox" name="mobileos" value="FR">
20 <span class="checkbox mn"></span>
21 </label>
22 </td>
23 <td>${space.floor}</td>
24 <td>${space.area}</td>
25 <td>${space.spaceId}</td>
26 <td>
27 <c:if test="${space.status == 0}">空闲</c:if>
28 <c:if test="${space.status == 1}">占用</c:if>
29 <c:if test="${space.status == 2}">预定</c:if>
30 </td>
31
32 <td>
33 <a href="/parkSpace/to_update?id=${space.id}">编辑</a>
34 <a href="/parkSpace/remove?id=${space.id}">删除</a>
35 </td>
36 </tr>
37 </c:forEach>
38 </tbody>
39 </table>
40 <p>当前 ${pageInfo.pageNum }页,总${pageInfo.pages }
41 页,总 ${pageInfo.total } 条记录
42 </p>
43 <a href="list?pageNo=${pageInfo.getFirstPage()}">首页</a>
44 <c:if test="${pageInfo.hasPreviousPage }">
45 <a href="list?pageNo=${pageInfo.pageNum-1}">上一页</a>
46 </c:if>
47
48 <c:if test="${pageInfo.hasNextPage }">
49 <a href="list?pageNo=${pageInfo.pageNum+1}">下一页</a>
50 </c:if>
51
52 <a href="list?pageNo=${pageInfo.getLastPage()}">末页</a>
53 </div>
最终的效果如图所示：
水平有限，表述还是很不好
原文地址：https://www.cnblogs.com/loki-dong/p/11002724.html
时间： 2024-08-27 22:14:32