java自定义标签

来源：互联网发布：炉石diy软件编辑：程序博客网时间：2024/06/01 21:13

三步：

一、自定义标签实现类： myTags.java;

二、自定义标签库文件（TLD）: myTags.tld;

三、一个JSP页面：随便写了;

首先myTags.java

package com.tags;import javax.servlet.jsp.JspException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.TagSupport;public class myTags extends TagSupport {public String name;public String getName() {return name;}public void setName(String name) {this.name = name;}public int doEndTag() throws JspException {JspWriter out = pageContext.getOut();//得到outtry{ out.println("<table bgColor=yellow>"); out.println("<tr>"); out.println("<td>"+ name +" : this is myTags!!</td>"); out.println("</tr>"); out.println("</table>"); }catch(Exception ex){ex.printStackTrace();}return this.EVAL_PAGE;}}

然后myTags.tld文件，在web-inf文件夹下生成，也可看做一个XML文件

<?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>1.2</tlibversion> <jspversion>1.1</jspversion> <shortname>mytags</shortname> <uri>mytags</uri> <tag> <name>showTable</name>  <tagclass>com.tags.myTags</tagclass>  <attribute> <name>name</name> <required>true</required>  <rtexprvalue>true</rtexprvalue>  </attribute></tag></taglib>

最后，来一个页面吧

<%@ page language="java" import="java.util.*" pageEncoding="GBK"%><%@ taglib uri="mytags" prefix="s"%><%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 'MyJsp.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"> </head> <body> showTable : <s:showTable name="sss"></s:showTable> </body></html>

注意：

一、页面中的代码, "mytags"对应的是tld文件中的<uri>节点;

<%@ taglib uri="mytags" prefix="s"%>

二、showTable是标签名，对应tld文件<name>节点，"name"可为输入参数

showTable : <s:showTable name="sss"></s:showTable>

over!!!!