您的位置: 首页  >  文章  >  自定义分页标签最新修改版

自定义分页标签最新修改版

分类: 文章 • 2025-01-06 22:33:04

 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: [email protected]
  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.****.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.****.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：自定义分页标签最新修改版

 

 

相关推荐