上一节谈了displaytag的基本用法，这一节就结合项目来看一下。按照常理，可能使用到displaytag的地方，
集中在管理页面里，譬如对博文的管理或者是针对comments的管理；相对而言category似乎并不需要使用分页；
很少会有人开几十个不同的分类吧 XD。
好吧，我们来比较一下，displaytag和原来的代码有什么不同。
这是原先的页面 网页的code：
1 <%@ page language="java" contentType="text/html; charset=UTF-8"%>
2 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
3 "http://www.w3.org/TR/html4/loose.dtd">
4 <%@page import="java.util.List" %>
5 <%@page import="java.text.SimpleDateFormat" %>
6 <%@page import="com.blog.Blog" %>
7 <%@page import="com.blog.Category" %>
8 <%@page import="com.blog.Comment" %>
9 <script type="text/javascript" language="JAVASCRIPT">
10 function del(){
11 var msg = "您真的确定要删除吗？\n\n请确认！";
12 if (confirm(msg)){
13 return true;
14 }else{
15 return false;
16 }
17 }
18 </script>
19 <div id="mainContent">
20 <% Category category = (Category) request.getAttribute("category");
21 if (category!=null){
22 out.print("<h3><a href='"+request.getContextPath()+"'>JAVA试验田</a>»"+category.getName()+"</h3>");
23 }
24 %>
25 <table>
26 <tr>
27 <th>主题</th>
28 <th></th>
29 <th></th>
30 </tr>
31
32 <% List blogs = (List) request.getAttribute("blogs");
33 if (blogs != null){
34 SimpleDateFormat fDate = new SimpleDateFormat("yyyy-MM-dd");
35 SimpleDateFormat fTime = new SimpleDateFormat("HH:mm");
36 for (int i=0;i<blogs.size();i++){
37 Blog blog = (Blog)blogs.get(i);%>
38 <tr>
39 <td><a href="<%=request.getContextPath()%>/BlogServlet?method=get&bid=<%=blog.getId()%>"><%=blog.getTitle()%></a> (<%=fDate.format(blog.getDate())%> <%=fTime.format(blog.getDate())%>)</td>
40 <td> <a href="<%=request.getContextPath()%>/BlogServlet?method=edit&bid=<%=blog.getId()%>"><img src="<%=request.getContextPath()%>/admin/img/edit.gif" border=0 alt="编辑"/></a></td>
41 <td> <a href="<%=request.getContextPath()%>/BlogServlet?method=delete&bid=<%=blog.getId()%>" onclick="javascript:return del()"><img src="<%=request.getContextPath()%>/admin/img/delete.gif" border=0 alt="删除"/></a></td>
42
43 </tr>
44
45 <% }
46 }
47 %>
48 </table>
49 <!-- end #mainContent --></div>
50 <!-- This clearing element should immediately follow the #mainContent div in order to force the #container div to contain all child floats --><br class="clearfloat" />
51
对比一下使用displayTag的页面显示
再看一下新的网页的写法：
1 <%@taglib uri="http://displaytag.sf.net" prefix="display" %>
2 <%@page import="java.util.List" %>
3 <%@page import="java.text.SimpleDateFormat" %>
4 <%@page import="com.blog.Blog" %>
5 <%@page import="com.blog.Category" %>
6 <%@page import="com.blog.Comment" %>
7 <script type="text/javascript" language="JAVASCRIPT">
8 function del(){
9 var msg = "您真的确定要删除吗？\n\n请确认！";
10 if (confirm(msg)){
11 return true;
12 }else{
13 return false;
14 }
15 }
16 </script>
17 <div id="mainContent">
18 <% Category category = (Category) request.getAttribute("category");
19 if (category != null) {
20 out.print("<h3><a href='" + request.getContextPath() + "'>JAVA试验田</a>»" + category.getName() + "</h3>");
21 }
22 %>
23 <display:table name="blogs" id="blog" pagesize="10" requestURI="/Blog/BlogServlet">
24 <display:column property="title" title="主题"/>
25 <display:column property="date" format="{0,date,yyyy-MM-dd HH:mm}" title="日期"/>
26 <display:column title="操作">
27 <a href="<%=request.getContextPath()%>/BlogServlet?method=edit&bid=${blog.id}"><img src="<%=request.getContextPath()%>/admin/img/edit.gif" border=0 alt="编辑" /></a>
28 <a href="<%=request.getContextPath()%>/BlogServlet?method=delete&bid=${blog.id}" onclick="javascript:return del()"><img src="<%=request.getContextPath()%>/admin/img/delete.gif" border=0 alt="删除"/></a>
29 </display:column>
30 </display:table>
31 <!-- end #mainContent --></div>
32 <!-- This clearing element should immediately follow the #mainContent div in order to force the #container div to contain all child floats --><br class="clearfloat" />
33
34
23行指定了displayTag显示每页10条数据。