jsp自定义标签自学札记（二）

2012-10-25

jsp自定义标签自学笔记（二）上一回学习了自定义标签库的写法。但是“hello world”级别的标签是远远不能满足我

jsp自定义标签自学笔记（二）
上一回学习了自定义标签库的写法。但是“hello world”级别的标签是远远不能满足我们如狼似虎的求知欲的。这回写个带名字的输入框。（知识就像美女，勇敢的扑过去吧！）

1、InputTag.java

package fox.tags.hello;import java.io.IOException;import javax.servlet.jsp.JspException;import javax.servlet.jsp.JspWriter;import javax.servlet.jsp.tagext.TagSupport;public class InputTag extends TagSupport{private String name="";public void setName(String name) {//set方法必须有this.name = name;}@Overridepublic int doStartTag() throws JspException {return normalInput();}private int normalInput(){JspWriter out=this.pageContext.getOut();StringBuffer sb=new StringBuffer("");sb.append("<input type="text" name="");sb.append(name);sb.append(""/>");try {out.write(sb.toString());} catch (IOException e) {e.printStackTrace();}return this.SKIP_BODY;}}

2、hello.tld

<?xml version="1.0" encoding="UTF-8"?><!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>shortname</short-name> <tag>  <name>hello</name>  <tag-class>fox.tags.hello.HelloTag</tag-class> </tag> <tag> <name>einput</name> <tag-class>fox.tags.hello.InputTag</tag-class> <attribute> <name>name</name> <required>false</required> <!-- rtexprvalue的全称是 Run-time Expression Value， 它用于表示是否可以使用JSP表达式. --> <rtexprvalue>true</rtexprvalue> </attribute> </tag></taglib>

3、web.xml的配置和（一）是相同的

<?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>  <jsp-config>  <taglib>  <taglib-uri>/hello-tags</taglib-uri>  <taglib-location>/WEB-INF/tld/hello.tld</taglib-location>  </taglib>  </jsp-config></web-app>

4、引用自定义的标签

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%><%@ taglib prefix="f" uri="/hello-tags"  %><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>  </head>    <body>    <f:hello></f:hello><br/>    <f:einput name="myname"></f:einput>  </body></html>

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jsp自定义标签自学札记（二）