java自定义标签的简单例子

1、处理类

package com;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

@SuppressWarnings("serial")
public class TestTag extends TagSupport {

	private String longtime;

	public String getLongtime() {
		return longtime;
	}

	public void setLongtime(String longtime) {
		this.longtime = longtime;
	}

	@Override
	public int doStartTag() throws JspException {

		long l = 0l;
		if (null != longtime && "".equals(longtime)) {
			l = Long.parseLong(longtime);
		}
		Date date = new Date(l);

		SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

		String date_string = sd.format(date);
		try {
			super.pageContext.getOut().print(date_string);
		} catch (IOException e) {
			e.printStackTrace();
		}
		return super.doStartTag();
	}

}

2、tld文件，放在WEB-INF下面

<?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>ct</short-name>  
 <uri>/dateConvert</uri>  
   
 <tag>  
    <name>longStr</name>  
    <tag-class>com.TestTag</tag-class>  
    <body-content>JSP</body-content>  
    <attribute>  
        <name>longtime</name>  
        <required>true</required>  
        <rtexprvalue>true</rtexprvalue>  
    </attribute>  
 </tag>  
</taglib>

3、web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	version="2.5">
	<jsp-config>
		<taglib>
			<taglib-uri>/dateConvert</taglib-uri>
			<taglib-location>dateConvert.tld</taglib-location>
		</taglib>
	</jsp-config>
</web-app>

4/jsp引用

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%>
<%@ taglib uri="/dateConvert" prefix="ct"%> 
<%
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 'index.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><ct:longStr longtime="1314842011312"></ct:longStr>  
      
  </body>
</html>

java自定义标签的简单例子

猜你喜欢