Java自定义标签详解：实现简单逻辑的高效展示-优快云博客

本文链接：https://blog.youkuaiyun.com/zhangchuanlong_ai/article/details/37697967

java自定义标签

jsp 自定义标签三板斧 ----->比较透彻的一篇学习材料，一句废话没有

自定义标签的目的：可以将实现复杂的逻辑在页面用简单的标签来加以展示

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：index.jsp;

源码：

-----------------------------------------------------------------------------------------------

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 {
    publicString name;
    publicString getName() {
       returnname;
    }
    public voidsetName(String name) {
       this.name =name;
    }
    public intdoEndTag() throws JspException {
       JspWriterout = pageContext.getOut();//得到out
       try{
         out.println("<tablebgColor=yellow>");
         out.println("<tr>");
         out.println("<td>"+ name +" : this ismyTags!!!</td>");
         out.println("</tr>");
         out.println("</table>");
         }catch(Exceptionex){ex.printStackTrace();}

       returnthis.EVAL_PAGE;
    }
}

-----------------------------------------------------------------------------------------------

myTags.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>1.2</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>

------------------------------------------------------------------------------------

index.jsp

<%@ 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 4.01Transitional//EN">
<html>
<head>
   <basehref="<%=basePath%>">

   <title>My JSP 'MyJsp.jsp' startingpage</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 mypage">
   

</head>

<body>
    showTable :<s:showTablename="sss"></s:showTable>
</body>
</html>