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spring mvc + hibernate 分页

2015-09-21 15:54 537 查看

   有关分页的问题已经老生常谈,在这里我展示一个简单的demo,并简单介绍下分页     的思路,思路理清了,代码也就好写了。

   简单分析一下理一下思路

第一,访问前台某个页面,需要在首页展示固定条数的数据,而且预先传递首页的参数(1)以及  pageSize;

第二,点击上一页:currentPage -1。点击下一页:currentPage +1。点击尾页:传递总页数-1处理。

第三,如果当前页是首页,则上一页不可点击(或者直接隐藏),如果当前页是末页,则下一页不可点击(或者直接隐藏)。

第四,通过点击不同的分页情况,从而使得currentPage的值一直变化,然后提交请求给springmvc,再通过hibernate的分页查询,通过传递的参数(当前页,每页显示条数)

可以从数据库查询需要的数据,并通过request对象存到servlet内置对象,同时返回一个试图。前台通过el表达式结合c标签进行遍历。

一、前台的jsp页面(展示分页的表格以及分页的前台代码 pages.jsp)

注意:该页面是从其他地方跳转过来的,可自行设置一个按钮,通过springmvc注解返回该视图(例如:location.href = "/userDetect/pageSelect.do?page=1&rows=20")。

<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<c:set var="ctx" value="${pageContext.request.contextPath}" />
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<script src="../resources/js/jquery-1.6.js" type="text/javascript"></script>
<script type="text/javaScript">
$(document).ready(function(){
var pagede = ${pageModel.currPage};
var pages = ${pageModel.pageCount};
if(pagede == 0){
$("#firstPage").attr("disabled","disabled");
$("#firstPage").css("cursor","text");
}else if(pagede == (pages-1)){
$("#lastPage").attr("disabled","disabled");
$("#lastPage").css("cursor","text");
}

})
function changePage(page){
page+=1;
var param = "?page=" + page;
param+="&rows=20";
location.href = "pageSelect.do"+ param;
}
</script>
<style type="text/css">
body {
font-size: 15px;
}
</style>
</head>
<body>
<table width="98%" border="0" cellpadding="2" cellspacing="1"
bgcolor="#D1DDAA" align="center"
style="position: relative; margin-top: 0px;">
<tr align="center" bgcolor="#EEF4EA">
<td>编号</td>
<td>Mac地址</td>
<td>连接类型</td>
<td>x坐标</td>
<td>y坐标</td>
<td>定位时间</td>
<td>位置源</td>
<td>路径</td>
<td>区域</td>
</tr>

<c:if test="${(pageModel.datas != null) && (!empty pageModel.datas)}">
<c:forEach items="${pageModel.datas}" var="item">
<tr align="center">
<td>${item.id}</td>
<td>${item.clientMac}</td>
<td>${item.clientType}</td>
<td>${item.x}</td>
<td>${item.y}</td>
<td>${item.timeStamp}</td>
<td>${item.locationSource}</td>
<td>${item.path}</td>
<td>${item.regions}</td>
</tr>
</c:forEach>
</c:if>
</table>
<div>
<table width="98%" border="0" cellpadding="2" cellspacing="1"
bgcolor="#D1DDAA" align="center"
style="position: relative; margin-top: 0px;">
<tr align="center" bgcolor="#EEF4EA">
<td height="36"><span
style="margin-top: 10px; margin-right: 50px">
共有${pageModel.totals }条数据, 每页显示${pageModel.pageSize }条数据,
当前是第${pageModel.currPage + 1}/${pageModel.pageCount }页 </span> <input
type="image" style="cursor: Pointer"
src="${ctx }/resources/images/my/first.gif" width="37" height="15"
onclick="javaScript:changePage(0)" /> <input id="firstPage"
type="image" style="cursor: Pointer"
src="${ctx }/resources/images/my/back.gif" width="43" height="15"
onclick="javaScript:changePage(${pageModel.currPage-1})" /> <input
id="lastPage" type="image" style="cursor: Pointer"
src="${ctx }/resources/images/my/next.gif" width="37" height="15"
onclick="javaScript:changePage(${pageModel.currPage+1})" /> <input
style="cursor: Pointer" type="image"
src="${ctx }/resources/images/my/last.gif" width="37" height="15"
onclick="javaScript:changePage(${pageModel.pageCount-1})" /> <span
class="STYLE1"> 转到第 <input style="cursor: Pointer"
id="inputPage" name="textfield" type="text" size="4"
style="height:12px; width:20px; border:1px solid #999999;" /> 页
</span> <span> <img id="aaa" style="cursor: Pointer"
src="${ctx }/resources/images/my/go.gif"
onclick='javaScript:changePage(document.getElementById("inputPage").value-1)'
width="37" height="15" />
</span></td>
</tr>
</table>
</div>

</body>
</html>


二 后台控制器(controler)代码(只是分页方法的代码,其他注入countInfoDao的代码省略)

public String pageSelect(ModelMap model, HttpServletRequest request,
HttpServletResponse response){
int page = Integer.parseInt(request.getParameter("page")); //当前页
int rows = Integer.parseInt(request.getParameter("rows"));//每页显示记录数
PageModel pageModel = countInfoDao.getPageModel(page-1, rows);
request.setAttribute("pageModel", pageModel);
return "pages";


三  (重点)包含实体类的javaBean文件:pageModel.java

import java.util.List;
public class PageModel {

/*翻页数据*/
@SuppressWarnings("rawtypes")
private List datas;
/*当前页*/
private int currPage;
/*每页显示的记录条数*/
private int pageSize = 20;//默认每页显示20条记录
/*总记录条数*/
private int totals;
/*总页数*/
private int pageCount;
/*后一页*/
private int nextPage;
/*前一页*/
private int prevPage;
/*翻页的地址*/
private String url;

public PageModel(){

}

/**
* 根据翻页要求构造翻页模型数据,默认每页显示20条
* @param totals
* 			总记录数
* @param datas
* 			翻页数据
* @param currPage
* 			当前页
*/
@SuppressWarnings("rawtypes")
public PageModel(int totals, List datas, int currPage){
this(totals, datas, 20, currPage);
}

/**
* 根据翻页的要求来构造翻页模型
* @param totals
* 			总记录数
* @param datas
* 			翻页数据
* @param pageSize
* 			每页显示的条数
* @param currPage
* 			当前页
*/
@SuppressWarnings("rawtypes")
public PageModel(int totals, List datas, int pageSize, int currPage){
this.totals = totals;
this.datas = datas;
this.pageSize = pageSize;
this.currPage = currPage;
if(totals % pageSize==0){
this.pageCount = totals / pageSize;
}else{
this.pageCount = totals / pageSize + 1;
}
this.nextPage = this.currPage + 1 > this.pageCount ? this.pageCount : this.currPage + 1;
this.prevPage = this.currPage - 1 < 1 ? 1:this.currPage - 1;

}

@SuppressWarnings("rawtypes")
public List getDatas() {
return datas;
}

@SuppressWarnings("rawtypes")
public void setDatas(List datas) {
this.datas = datas;
}
public int getCurrPage() {
return currPage;
}
public void setCurrPage(int currPage) {
this.currPage = currPage;
}
public int getPageSize() {
return pageSize;
}
public int getTotals() {
return totals;
}
public int getPageCount() {
return pageCount;
}
public int getNextPage() {
return nextPage;
}
public int getPrevPage() {
return prevPage;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}

}


四、dao层的代码(抽象方法)

PageModel getPageModel(Integer currentPage, Integer rows);



四、daoImp代码

/**
* 分页查询
*/
@Override
public PageModel getPageModel(Integer currentPage, Integer rows) {
int totals = getAllCount();
List<LocationInfoEntity> datas = getAll(currentPage, rows);<span style="white-space:pre">	</span>
return new PageModel(totals, datas, rows, currentPage);
}
/*获取总的条数
*/
public int getAllCount() {
// TODO Auto-generated method stub
// TODO Auto-generated method stub
StringBuffer sb = new StringBuffer();
sb.append("select count(id) from LocationInfoEntity m where 1=1");
int countAll = Integer.parseInt(getHibernateTemplate().find(sb.toString()).get(0).toString());、、
return countAll;
}
/*获得表中的数据
*/

public List<LocationInfoEntity> getAll(int currPage,
int pageSize){
StringBuffer sb = new StringBuffer();
sb.append("from LocationInfoEntity as lo");
Query query = getHibernateTemplate().getSessionFactory().getCurrentSession().createQuery(sb.toString());
query.setFirstResult(currPage*pageSize);
query.setMaxResults(pageSize);
return query.list();
}
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标签:  springmvc hibernate