自定义分页标签最新修改版

 一、标签处理类：

1. /**
2.  *  ClassName: PagerTag.java
3.  *  created on Oct 21, 2008
4.  *  Copyrights 2008 qjyong All rights reserved.
5.  *  EMail: [e-mail]
6.  */
7. package com.qiujy.tags;
9. import java.io.IOException;
10. import java.util.Enumeration;
12. import javax.servlet.http.HttpServletRequest;
13. import javax.servlet.jsp.JspException;
14. import javax.servlet.jsp.tagext.TagSupport;
16. /**
17.  * 自定义分页标签 
18.  * 使用方式 <my:pager pageSize="10" 
19.  *                   pageNo="1" 
20.  *                   recordCount="100"
21.  *                   url="index.jsp" />
22.  * 
23.  * @author qiujy
24.  * 
25.  */
26. public class PagerTag extends TagSupport {
27.     private int pageSize = 10; // 每页要显示的记录数
28.     private int pageNo = 1; // 页号
29.     private int recordCount; // 总记录数
30.     private String url; // 目的地URL
31.     
32.     public void setPageSize(int pageSize) {
33.         this.pageSize = pageSize;
34.     }
36.     public void setPageNo(int pageNo) {
37.         this.pageNo = pageNo;
38.     }
40.     public void setRecordCount(int recordCount) {
41.         this.recordCount = recordCount;
42.     }
44.     public void setUrl(String url) {
45.         this.url = url;
46.     }
48.     // 主要的逻辑
49.     @Override
50.     public int doStartTag() throws JspException {
51.         if(recordCount == 0){
52.             return super.doStartTag();
53.         }
54.         
55.         // 总页数
56.         int pageCount = (recordCount + pageSize - 1) / pageSize;
58.         // 页号越界处理
59.         if (pageNo > pageCount) {
60.             pageNo = pageCount;
61.         }
62.         if (pageNo < 1) {
63.             pageNo = 1;
64.         }
65.         
66.         StringBuilder sb = new StringBuilder();
67.         
68.         sb.append("<form name='pageController' id='pageController' action='' method='post'>\r\n")
69.           .append("<input type='hidden' id='pageNo' name='pageNo' value='" + pageNo + "' />\r\n");
70.         
71.         //------------------------------------ 获取所有請求中的参数
72.         HttpServletRequest request = (HttpServletRequest) pageContext
73.                 .getRequest();
74.         Enumeration<String> enumeration = request.getParameterNames();
75.         String name = null;
76.         String value = null;
77.         //把请求中的所有参数当作隐藏表单域在页面中写出)
78.         while (enumeration.hasMoreElements()) {
79.             name =  enumeration.nextElement();
80.             value = request.getParameter(name);
82.             // 去除页号
83.             if (name.equals("pageNo")) {
84.                 if (null != value && !"".equals(value)) {
85.                     pageNo = Integer.parseInt(value);
86.                 }
87.                 continue;
88.             }
89.             sb.append("<input type='hidden' name='")
90.               .append(name)
91.               .append("' value='")
92.               .append(value)
93.               .append("'/>\r\n");
94.         }
95.         //----------------------------------------------------
96.         
97.           
98.         sb.append(" 总共有" + pageCount + "页,")
99.           .append("当前是第" + pageNo + "页 \r\n");
100.         
101.         if (pageNo == 1) {
102.             sb.append("首页");
103.             sb.append(" ");
104.             sb.append("上一页\r\n");
106.         } else {
107.             sb.append("<a href='#' onclick='turnOverPage(1)'>首页</a>\r\n");
108.             sb.append(" ");
109.             sb.append("<a href='#' onclick='turnOverPage(")
110.                     .append((pageNo - 1)).append(")'>上一页</a>\r\n");
111.         }
113.         sb.append(" ");
114.         if (pageNo == pageCount) {
115.             sb.append("下一页");
116.             sb.append(" ");
117.             sb.append("尾页\r\n");
119.         } else {
120.             sb.append("<a href='#' onclick='turnOverPage(")
121.                     .append((pageNo + 1)).append(")'>下一页</a>\r\n");
122.             sb.append(" ");
123.             sb.append("<a href='#' onclick='turnOverPage(").append(pageCount)
124.                     .append(")'>尾页</a>\r\n");
125.         }
126.         
127.         sb.append(" 跳到<select onChange='turnOverPage(this.value)'>\r\n");
128.         for (int i = 1; i <= pageCount; i++) {
129.             if (i == pageNo) {
130.                 sb.append("  <option value='")
131.                   .append(i)
132.                   .append("' selected='selected'>第")
133.                   .append(i)
134.                   .append("页</option>\r\n");
135.             } else {
136.                 sb.append("  <option value='")
137.                   .append(i)
138.                   .append("'>第")
139.                   .append(i)
140.                   .append("页</option>\r\n");
141.             }
142.         }
143.         sb.append("</select>\r\n");
144.         sb.append(" \r\n");
145.         sb.append("</form>\r\n");
146.         
147.         // 生成提交表单的JS
148.         sb.append("<script language='javascript'>\r\n");
149.         sb.append("  //翻页函数\t\n");
150.         sb.append("  function turnOverPage(no){\r\n");
151.         sb.append("    var form = document.pageController;\r\n");
152.         sb.append("    //页号越界处理\r\n");
153.         sb.append("    if(no").append(">").append(pageCount).append(") {\r\n");
154.         sb.append("        no=").append(pageCount).append(";\r\n");
155.         sb.append("    }\r\n");
156.         sb.append("    if(no").append("< 1){\r\n");
157.         sb.append("        no=1;\r\n");
158.         sb.append("    }\r\n");
159.         sb.append("    form.").append("pageNo").append(".value=no;\r\n");
160.         sb.append("    form.action='").append(url).append("';\r\n");
161.         sb.append("    form.submit();\r\n");
162.         sb.append("  }\r\n");
163.         sb.append("</script>\r\n");
164.         
165.         try {
166.             pageContext.getOut().println(sb.toString());
167.         } catch (IOException e) {
168.             e.printStackTrace();
169.         }
170.         
171.         return super.doStartTag();
172.     }
174. }

二、标签库描述文件：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <taglib version="2.0" xmlns="http://java.sun.com/xml/ns/j2ee"
3.  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee web-jsptaglibrary_2_0.xsd">
4.  <tlib-version>2.0</tlib-version>
5.  <short-name>my</short-name>
6.  <uri>http://blog.csdn.net/qjyong</uri>
7.  <tag>
8.     <description>通用分页标签</description>
9.     <name>pager</name>
10.     <tag-class>com.qiujy.tags.PagerTag</tag-class>
12.     <body-content>empty</body-content>
13.     <attribute>
14.       <name>pageNo</name>
15.       <required>true</required>
16.       <rtexprvalue>true</rtexprvalue> 
17.     </attribute>
18.     <attribute>
19.       <name>recordCount</name>
20.       <required>true</required>
21.       <rtexprvalue>true</rtexprvalue>
22.     </attribute>
23.     <attribute>
24.       <name>pageSize</name>
25.       <required>true</required>
26.       <rtexprvalue>true</rtexprvalue>
27.     </attribute>
28.     <attribute>
29.       <name>url</name>
30.       <required>true</required>
31.       <rtexprvalue>true</rtexprvalue>
32.     </attribute>
33.   </tag>
34. </taglib>

三、把标签处理类和tld打成pager.jar包。使用时只需添加到项目的类路径中即可。

 

四、测试：先写一个Servlet来创建测试数据

1. package com.qiujy.web.servlet;
3. import java.io.IOException;
4. import java.util.ArrayList;
5. import java.util.List;
7. import javax.servlet.ServletException;
8. import javax.servlet.http.HttpServlet;
9. import javax.servlet.http.HttpServletRequest;
10. import javax.servlet.http.HttpServletResponse;
12. public class MyServlet extends HttpServlet {
13.     
14.     public static List<String> list = new ArrayList<String>();
15.     
16.     public MyServlet(){
17.         for(int i = 0; i < 100; i++){
18.             list.add("aaa" + i);
19.         }
20.     }
22.     public void doGet(HttpServletRequest request, HttpServletResponse response)
23.             throws ServletException, IOException {
24.         this.doPost(request, response);
25.     }
27.     public void doPost(HttpServletRequest request, HttpServletResponse response)
28.             throws ServletException, IOException {
29.         String pageNoStr = request.getParameter("pageNo");
30.         int pageNo = 1;
31.         if(pageNoStr != null && !pageNoStr.equals("")){
32.             pageNo = Integer.parseInt(pageNoStr);
33.         }
34.         
35.         int recordCount = list.size();
36.         int pageSize = 10;
37.         int startNo = (pageNo - 1) * pageSize;
38.         
39.         List<String> result = list.subList(startNo, startNo + 10);
40.         
41.         request.setAttribute("recordCount", recordCount);
42.         request.setAttribute("pageNo", pageNo);
43.         request.setAttribute("pageSize", pageSize);
44.         request.setAttribute("data", result);
45.         
46.         request.getRequestDispatcher("index.jsp").forward(request, response);
47.     }
48. }

web.xml：

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee"
3.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
4.     xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
5.     http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">
7.     <servlet>
8.         <servlet-name>pageTestServlet</servlet-name>
9.         <servlet-class>com.qiujy.web.servlet.MyServlet</servlet-class>
10.     </servlet>
12.     <servlet-mapping>
13.         <servlet-name>pageTestServlet</servlet-name>
14.         <url-pattern>/testpager</url-pattern>
15.     </servlet-mapping>
16.     
17.     <welcome-file-list>
18.         <welcome-file>index.jsp</welcome-file>
19.     </welcome-file-list>
20. </web-app>

 

页面：index.jsp

1. <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
2. <%@ taglib uri="http://blog.csdn.net/qjyong" prefix="q" %>
3. <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
4. <html>
5.   <head>
6.     <title>PagerTag使用示例</title>
7.   </head>
8.   
9.   <body>
10.     <% 
11.       List<String> list = (List<String>)request.getAttribute("data");
12.       for(String str : list){
13.         out.println(str + "<br/>");
14.       }
15.     %>
16.     
17.     <q:pager pageNo="${pageNo}" 
18.                  recordCount="${recordCount}"
19.              pageSize="${pageSize}" 
20.              url="testpager" />
21.   </body>
22. </html>

 

访问testpager后的效果图：

 

 

评论

3 楼 weideming 2008-12-23  

       错了，那个该是/除号，写成%百分号了
List<String> result = new ArrayList();
if(pageNo == (recordCount/pageSize+1)){
          result = list.subList(startNo,recordCount);
}else{
          result = list.subList(startNo, startNo + 10);
}

2 楼 weideming 2008-12-23  

    Servlet里面 这样稍微修改下该很好用了,
    用subList()好像没有充足的数据就会报错

         List<String> result = new ArrayList();
if(pageNo == (recordCount%pageSize+1)){
result = list.subList(startNo,recordCount);
}else{
result = list.subList(startNo, startNo + 10);
}

1 楼 weideming 2008-12-23  

        99条记录的话，最后一页将报错