分页技术原理与实现之无刷新的Ajax分页技术(三)
紧接着上篇—分页技术原理与实现之Java+Oracle代码实现分页(二) ，本篇继续分析分页技术。上篇讲的是分页技术的代码实现，这篇继续分析一下分页技术的效果控制。
上篇已经用代码简单的实现了一个分页。但是我们都看到，代码中每次通过servlet请求取得结果集后，都会转向到一个jsp页面显示结果，这样每次查询页面都会刷新一下，比如查询出现结果集后要查看第三页，页面就会刷新一下。这样页面给人的效果感觉就会有点不舒服，所以我们希望能够在通过条件查询结果集后无论访问哪一页，页面都不会刷新，而只是结果集变化。要解决这个，我想大家很容易就会想到Ajax了。
是啊，这就要请Ajax出山了。当通过查询条件查询到结果集后，以后每次访问任何一页都通过Ajax来访问，使用异步Ajax与Servlet进行交互，将结果查询出来返回给Ajax，这样页面内容因为Ajax返回结果而改变，而页面却不会刷新，这就实现了无刷新的分页技术。
下面我们来看一个简单的无刷新分页实现，代码如下：
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link rel="stylesheet" href="../lib/jquery_pagination/pagination.css" mce_href="lib/jquery_pagination/pagination.css" />
<mce:script type="text/<a href="http://lib.csdn.net/base/javascript" class='replace_word' title="JavaScript知识库" target='_blank' style='color:#df3434; font-weight:bold;'>JavaScript</a>" src="../lib/<a href="http://lib.csdn.net/base/jquery" class='replace_word' title="jQuery知识库" target='_blank' style='color:#df3434; font-weight:bold;'>jQuery</a>/jquery.min.js" mce_src="lib/jquery/jquery.min.js"></mce:script>
<mce:script type="text/javascript"
src="../lib/jquery_pagination/jquery.pagination.js"></mce:script>
<mce:script type="text/javascript"><!--
/**
* Callback function that displays the content.
*
* Gets called every time the user clicks on a pagination link.
*
* @param {int}page_index New Page index
* @param {jQuery} jq the <a href="http://lib.csdn.net/base/docker" class='replace_word' title="Docker知识库" target='_blank' style='color:#df3434; font-weight:bold;'>Container</a> with the pagination links as a jQuery object
*/
function pageselectCallback(page_index, jq) {
var new_content = $('#hiddenresult div.result:eq(' + page_index + ')')
.clone();
$('#Searchresult').empty().append(new_content);
return false;
}
function initPagination() {
var num_entries = $('#hiddenresult div.result').length;
// Create pagination element
$("#Pagination").pagination(num_entries, {
num_edge_entries : 2,
num_display_entries : 8,
callback : pageselectCallback,
items_per_page : 1
});
}
// When the HTML has loaded, call initPagination to paginate the elements
$(document).ready(function() {
initPagination();
});
// --></mce:script>
<mce:style type="text/css"><!--
* {
padding: 0;
margin: 0;
}
body {
background-color: #fff;
margin: 20px;
padding: 0;
height: 100%;
font-family: Arial, Helvetica, sans-serif;
}
#Searchresult {
margin-top: 15px;
margin-bottom: 15px;
border: solid 1px #eef;
padding: 5px;
background: #eef;
width: 40%;
}
#Searchresult p {
margin-bottom: 1.4em;
}
--></mce:style><style type="text/css" mce_bogus="1">* {
padding: 0;
margin: 0;
}
body {
background-color: #fff;
margin: 20px;
padding: 0;
height: 100%;
font-family: Arial, Helvetica, sans-serif;
}
#Searchresult {
margin-top: 15px;
margin-bottom: 15px;
border: solid 1px #eef;
padding: 5px;
background: #eef;
width: 40%;
}
#Searchresult p {
margin-bottom: 1.4em;
}</style>
<title>Pagination</title>
</head>
<body>
<h4>
jQuery Pagination Plugin Demo
</h4>
<div id="Pagination" class="pagination">
</div>
<br style="clear: both;" mce_style="clear: both;" />
<div id="Searchresult">
This content will be replaced when pagination inits.
</div>
<div id="hiddenresult" style="display: none;" mce_style="display: none;">
<div class="result">
<p>
Globally maximize granular "outside the box" thinking vis-a-vis
quality niches. Proactively formulate 24/7 results whereas 2.0
catalysts for change. Professionally implement 24/365 niches rather
than client-focused users.
</p>
<p>
Competently engineer high-payoff "outside the box" thinking through
cross functional benefits. Proactively transition intermandated
processes through open-source niches. Progressively engage
maintainable innovation and extensible interfaces.
</p>
</div>
<div class="result">
<p>
Credibly fabricate e-business models for end-to-end niches.
Compellingly disseminate integrated e-markets without ubiquitous
services. Credibly create equity invested channels with
multidisciplinary human capital.
</p>
<p>
Interactively integrate competitive users rather than fully tested
infomediaries. Seamlessly initiate premium functionalities rather
than impactful architectures. Rapidiously leverage existing
resource-leveling processes via user-centric portals.
</p>
</div>
<div class="result">
<p>
Monotonectally initiate unique e-services vis-a-vis client-centric
deliverables. Quickly impact parallel opportunities with B2B
bandwidth. Synergistically streamline client-focused
infrastructures rather than B2C e-commerce.
</p>
<p>
Phosfluorescently fabricate 24/365 e-business through 24/365 total
linkage. Completely facilitate high-quality systems without
stand-alone strategic theme areas.
</p>
</div>
</div>
</body>
</html>
这就是一个非常简单的无刷新分页实现，使用了JQuery+ jquery.pagination框架。现在随着框架的流行，尤其是Jquery的流行，使用框架来开发是非常有效的。上面代码原理在代码中已有注释，也可参考Jquery的官方网站：。
现在就可以来开发我们的Ajax无刷新分页实现。基于上面的原理，在响应页码被按下的代码中pageselectCallback()，我们使用一个Ajax异步访问数据库，通过点击的页号将结果集取出后再用异步设置到页面，这样就可以完成了无刷新实现。
页码被按下的响应函数pageselectCallback()修改如下：
这样就可以用异步方式获取结果，用showResponse函数来处理结果了，showResponse函数如下：
function showResponse(request){
var content = request;
var root = content.documentElement;
var responseNodes = root.getElementsByTagName("root");
var itemList = new Array();
var pageList=new Array();
alert(responseNodes.length);
if (responseNodes.length > 0) {
var responseNode = responseNodes[0];
var itemNodes = responseNode.getElementsByTagName("data");
for (var i=0; i<itemNodes.length; i++) {
var idNodes = itemNodes[i].getElementsByTagName("id");
var nameNodes = itemNodes[i].getElementsByTagName("name");
var sexNodes=itemNodes[i].getElementsByTagName("sex");
var ageNodes=itemNodes[i].getElementsByTagName("age");
if (idNodes.length > 0 && nameNodes.length > 0&&sexNodes.length > 0&& ageNodes.length > 0) {
var id=idNodes[0].firstChild.nodeValue;
var name = nameNodes[0].firstChild.nodeValue;
var sex = sexNodes[0].firstChild.nodeValue;
var age=ageNodes[0].firstChild.nodeValue;
itemList.push(new Array(id,name, sex,age));
}
}
var pageNodes = responseNode.getElementsByTagName("pagination");
if (pageNodes.length>0) {
var totalNodes = pageNodes[0].getElementsByTagName("total");
var startNodes = pageNodes[0].getElementsByTagName("start");
var endNodes=pageNodes[0].getElementsByTagName("end");
var currentNodes=pageNodes[0].getElementsByTagName("pageno");
if (totalNodes.length > 0 && startNodes.length > 0&&endNodes.length > 0) {
var total=totalNodes[0].firstChild.nodeValue;
var start = startNodes[0].firstChild.nodeValue;
var end = endNodes[0].firstChild.nodeValue;
var current=currentNodes[0].firstChild.nodeValue;
pageList.push(new Array(total,start,end,current));
}
}
}
showTable(itemList,pageList);
}
如上代码就是用来处理通过Ajax异步请求Servlet后返回的XML格式的结果，其中Servlet代码在上篇中。其中itemList、pageList分别是解析返回后生成的用户List和分页导航，这样用户就可以以自己的展现方式展现数据了。
function pageselectCallback(page_index, jq){
var pars="pageNo="+(page_index+1);
$.ajax({
type: "POST",
url: " UserBasicSearchServlet",
cache: false,
data: pars,
success: showResponse
});
return false;
}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。