jsp通过自定义标签库实现数据列表显示的方法
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2023-08-24 16:59:11
本文实例讲述了jsp通过自定义标签库实现数据列表显示的方法。分享给大家供大家参考,具体如下:
1. 定义标签库类 userlisttag.java
packag...
本文实例讲述了jsp通过自定义标签库实现数据列表显示的方法。分享给大家供大家参考,具体如下:
1. 定义标签库类 userlisttag.java
package com.yanek.cms.tag; import java.io.ioexception; import java.util.arraylist; import java.util.iterator; import java.util.list; import javax.servlet.jsp.jspexception; import javax.servlet.jsp.tagext.bodytagsupport; import com.yanek.cms.vo.userinfo; public class userlisttag extends bodytagsupport { private string name;// 一个属性名 private iterator it;// 要迭代的对象 private int cateid; // 用户类别id @override public int doendtag() throws jspexception { try { if (bodycontent != null) { bodycontent.writeout(bodycontent.getenclosingwriter()); } } catch (ioexception e) { e.printstacktrace(); } return eval_page; } @override public int dostarttag() throws jspexception { //这里根据用户类型,构造不同的列表数据,实现可以根据数据库获取 list<userinfo> users = new arraylist<userinfo>(); if (cateid == 1) { users.add(new userinfo("张三", 20, "zhangsan@163.com")); users.add(new userinfo("李四", 30, "lisi@sina.com")); } else { users.add(new userinfo("王五", 33, "wangwu@qq.com")); users.add(new userinfo("赵六", 33, "zhaoliu@qq.com")); } it = users.iterator(); if (it == null) { return skip_body; } else { return continuenext(); } } private int continuenext() { if (it.hasnext()) { pagecontext.setattribute(name, it.next(), pagecontext.page_scope); return eval_body_tag; } else { return skip_body; } } @override public int doafterbody() { return continuenext(); } public string getname() { return name; } public void setname(string name) { this.name = name; } public int getcateid() { return cateid; } public void setcateid(int cateid) { this.cateid = cateid; } }
2. 在web-inf目录下 新建标签库描述文件my_cms_tag.tld:
my_cms_tag.tld
<?xml version="1.0" encoding="utf-8"?> <!doctype taglib public "-//sun microsystems, inc.//dtd jsp tag library 1.1//en" "http://java.sun.com/j2ee/dtds/web-jsptaglibrary_1_1.dtd"> <taglib> <tlibversion>1.0</tlibversion> <jspversion>1.0</jspversion> <shortname>cms</shortname> <uri>http://www.58tech.cn/mystruts/tags-cms</uri> <!-- userlisttag start --> <tag> <name>userlisttag</name> <tag-class>com.yanek.cms.tag.userlisttag</tag-class> <body-content>jsp</body-content> <variable> <!--<name-given>user_info</name-given>--> <name-from-attribute>name</name-from-attribute> <variable-class>com.yanek.cms.vo.userinfo</variable-class> <declare>true</declare> <scope>nested</scope> </variable> <attribute> <name>name</name> <required>true</required> </attribute> <attribute> <name>cateid</name> <required>true</required> </attribute> </tag> <!-- userlisttag end --> </taglib>
3. web.xml配置
<?xml version="1.0" encoding="utf-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/xmlschema-instance" xsi:schemalocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <taglib> <taglib-uri>/tags/my-cms</taglib-uri> <taglib-location>/web-inf/my_cms_tag.tld</taglib-location> </taglib> </web-app>
4. jsp调用
<%@ page language="java" import="java.util.*,com.yanek.cms.vo.*" pageencoding="utf-8"%> <%@ taglib uri="/tags/my-cms" prefix="mytag" %> <% string path = request.getcontextpath(); string basepath = request.getscheme()+"://"+request.getservername()+":"+request.getserverport()+path+"/"; %> <!doctype html public "-//w3c//dtd html 4.01 transitional//en"> <html> <head> <base href="<%=basepath%>"> <title>my jsp 'test.jsp' starting page</title> <meta http-equiv="pragma" content="no-cache"> <meta http-equiv="cache-control" content="no-cache"> <meta http-equiv="expires" content="0"> <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> <meta http-equiv="description" content="this is my page"> <!-- <link rel="stylesheet" type="text/css" href="styles.css"> --> </head> <body> <table width='500px' border='1' align='center'> <tr> <td width='20%'>username</td> <td width='20%'>age</td> <td>email</td> </tr> <mytag:userlisttag name="user_info1" cateid="1"> <tr> <td><%=user_info1.getusername() %></td> <td><%=user_info1.getage() %></td> <td><%=user_info1.getemail() %> </td> </tr> </mytag:userlisttag> </table> <hr> <table width='500px' border='1' align='center'> <tr> <td width='20%'>username</td> <td width='20%'>age</td> <td>email</td> </tr> <mytag:userlisttag name="user_info2" cateid="2"> <tr> <td><%=user_info2.getusername() %></td> <td><%=user_info2.getage() %></td> <td><%=user_info2.getemail() %> </td> </tr> </mytag:userlisttag> </table> </body> </html>
实体类定义
package com.yanek.cms.vo; public class userinfo { private int age; private string username; private string email; public int getage() { return age; } public void setage(int age) { this.age = age; } public string getusername() { return username; } public void setusername(string username) { this.username = username; } public string getemail() { return email; } public void setemail(string email) { this.email = email; } public userinfo(string username,int age, string email) { super(); this.age = age; this.username = username; this.email = email; } public userinfo() { } }
运行效果如下图 (url输入:http://127.0.0.1:8080/testcms/page/userlist.jsp)
完整实例代码代码点击此处。
希望本文所述对大家android程序设计有所帮助。