tld定义格式
- <?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>
- <!--定义标签版本库-->
- <tlib-version>1.0</tlib-version>
- <!--定义jsp版本库-->
- <jsp-version>1.2</jsp-version>
- <short-name>Cms Tag</short-name>
- <description><!--标签描述--->
- A simple appbase tag library
- </description>
- <tag>
- <name>page</name><!--tag的名字-->
- <tag-class>com.cms.common.tag.PageTag</tag-class><!--tag对应的java类的名字-->
- <body-content>empty</body-content>
- <!--关于body-content 有三个值可选;empty:标签体必须为空;jsp:标签由其他jsp元素组成比如标签中含有<%=attributeName%>的jsp元素,那么此时body-content的值就是实际attributeName传入的值;tagdependent:有标签解释不带jsp转换(这个深入的含义不太了解)-->
- <attribute><!---这里表示的是这个tag的一个参数-->
- <name>cmsform</name><!--这个参数的名字-->
- <required>true</required><!--是否是必填选项-->
- <rtexprvalue>true</rtexprvalue><!--这个参数的值是否可以写入,换句话说 就是这个参数是否可以动态赋值-->
- </attribute>
- </tag>
- </taglib>
定义Tag对应类
此类必须重写doStartTag以及doEndTag方法
- /**
- *
- */
- package com.cms.common.tag;
- import javax.servlet.jsp.JspException;
- import javax.servlet.jsp.JspWriter;
- import javax.servlet.jsp.tagext.TagSupport;
- /**
- * @author louisliao
- *
- */
- public class DemoViewTag extends TagSupport {
- /**
- *
- */
- private static final long serialVersionUID = 1L;
- private String cmsform = "";
- public String getCmsForm() {
- return cmsform ;
- }
- public void setCmsForm(String cmsform ) {
- this.cmsform = cmsform ;
- }
- /**
- *
- */
- public DemoViewTag() {
- // TODO Auto-generated constructor stub
- }
- public int doStartTag()
- {
- return super.SKIP_BODY;
- }
- public int doEndTag() throws JspException
- {
- JspWriter writer=pageContext.getOut();
- try {
- writer.print("这是我的标签示例<br/>"+"cmsform :"+this.cmsform);
- } catch (Exception e) {
- // TODO: handle exception
- e.printStackTrace();
- }
- return super.EVAL_PAGE;
- }
- }
在web.xml中加入taglib对应文件配置
如:
- <taglib>
- <taglib-uri>http://mytag.sf.net</taglib-uri>
- <taglib-location>/WEB-INF/mytag.tld</taglib-location>
- </taglib>
这样就表示了http://mytag.sf.net对应WEB-INF/mytag.tld文件
在Jsp页面中引用
如:
<%@ taglib uri="http://mytag.sf.net" prefix="myTag"%>
在Jsp页面中使用
<myTag:exname1><myTag:exname1>
示例:
定义myTag.tld标签文件
- <?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>1.0</tlibversion>
- <jspversion>1.1</jspversion>
- <shortname>MyJSPTag Library</shortname>
- <uri>http://mytag.sf.net</uri>
- <info>我的示例标签库</info>
- <tag>
- <name>demo.Viewport</name>
- <tagclass>com.myapp.web.tag.DemoViewTag</tagclass>
- <bodycontent>JSP</bodycontent>
- <info>demo.Viewport标签</info>
- <attribute>
- <name>northTitle</name>
- <required>true</required>
- <rtexprvalue>true</rtexprvalue>
- </attribute>
- <attribute>
- <name>westTitle</name>
- <required>true</required>
- <rtexprvalue>true</rtexprvalue>
- </attribute>
- </tag>
- </taglib>
定义标签类
- /**
- *
- */
- package com.myapp.web.tag;
- import javax.servlet.jsp.JspException;
- import javax.servlet.jsp.JspWriter;
- import javax.servlet.jsp.tagext.TagSupport;
- /**
- * @author louisliao
- *
- */
- public class DemoViewTag extends TagSupport {
- /**
- *
- */
- private static final long serialVersionUID = 1L;
- private String northTitle = "";
- private String westTitle = "";
- public String getNorthTitle() {
- return northTitle;
- }
- public void setNorthTitle(String northTitle) {
- this.northTitle = northTitle;
- }
- public String getWestTitle() {
- return westTitle;
- }
- public void setWestTitle(String westTitle) {
- this.westTitle = westTitle;
- }
- /**
- *
- */
- public DemoViewTag() {
- // TODO Auto-generated constructor stub
- }
- public int doStartTag()
- {
- return super.SKIP_BODY;
- }
- public int doEndTag() throws JspException
- {
- JspWriter writer=pageContext.getOut();
- try {
- writer.print("这是我的标签示例<br/>westTitle:"+this.westTitle+"<br/>northTitle:"+this.northTitle);
- } catch (Exception e) {
- // TODO: handle exception
- e.printStackTrace();
- }
- return super.EVAL_PAGE;
- }
- }
web.xml添加配置
- <taglib>
- <taglib-uri>http://mytag.sf.net</taglib-uri>
- <taglib-location>/WEB-INF/mytag.tld</taglib-location>
- </taglib>
测试页面
- <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
- <%@ taglib uri="http://mytag.sf.net" 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 'tagtldDemo.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>
- This is my JSP page. <br>
- <myTag:demo.Viewport northTitle="南" westTitle="西"></myTag:demo.Viewport>
- </body>
- </html>