jsp标签取代了JSP中的Java程序，并且可以重复使用，方便不熟悉Java编程的网页设计人员。
首先在eclipse下新建一个动态web工程1,在</web-app>之前加入<jsp-config><taglib><taglib-uri>/tld/helloworld</taglib-uri><taglib-location>/WEB-INF/tlds/helloworld.tld</taglib-location></taglib></jsp-config>2.在WEB-INF下新建tlds目录,在tlds下新建helloworld.tld.helloworld.tld的内容为<?xml version="1.0" encoding="ISO-8859-1"?><!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN""http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd"><taglib><tlib-version>1.0</tlib-version><jsp-version>1.2</jsp-version><short-name>mytag</short-name><tag><name>helloworld</name><tag-class>mytag.HelloWorldTag</tag-class><body-content>empty</body-content></tag></taglib> 3.在src的mytag包下新建类HelloWorldTag.javapackage mytag;}public int doStartTag() throws JspTagException...{return EVAL_BODY_INCLUDE;}public int doEndTag() throws JspTagException...{try...{pageContext.getOut().write("This is a jsp tag test!");}catch(IOException ex)...{throw new JspTagException("错误");}return EVAL_PAGE;}}测试页面hello.jspimport java.io.IOException;import javax.servlet.jsp.JspTagException;import javax.servlet.jsp.tagext.TagSupport;public class HelloWorldTag extends TagSupport...{public HelloWorldTag()...<%...@ page language="java" contentType="text/html; charset=gb2312"<pageEncoding="gb2312"%><%...@ page import="java.util.*"%><%...@ page import="jstl.*"%><%...@ taglib prefix="mytag" uri="/tld/helloworld"%><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=gb2312"><title>Insert title here</title></head><body><h1>自定义标签:</h1><br><br><mytag:helloworld></mytag:helloworld><br></form></body></html>
