如何编写一个简单的 taglib

来源：互联网发布：尤克里里调音的软件编辑：程序博客网时间：2024/05/20 17:23

这是一个显示年月日的taglib，希望对初学者有所帮助。

编写实现类（MyDateTag .java）：

package com;

import java.util.*;

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

/** * @author wpabbs * * TODO 要更改此生成的类型注释的模板，请转至窗口－首选项－ Java －代码样式－代码模板 */public class MyDateTag extends TagSupport {

public int doEndTag() throws JspException { // TODO 自动生成方法存根 JspWriter out = pageContext.getOut(); Calendar cal = Calendar.getInstance(); int year = cal.get(Calendar.YEAR); int month = cal.get(Calendar.MONTH) + 1; int dates = cal.get(Calendar.DAY_OF_MONTH); int day = cal.get(Calendar.DAY_OF_WEEK); day -= 1; String week = "星期一";

if (day == 0) week = "星期日"; else if (day == 1) week = "星期一"; else if (day == 2) week = "星期二"; else if (day == 3) week = "星期三"; else if (day == 4) week = "星期四"; else if (day == 5) week = "星期五"; else if (day == 6) week = "星期六";

try { out.print("今天是" + year + "年" + month + "月" + dates + "日," + week); } catch (Exception e) {

} return super.doEndTag(); }}

=============================================================

编写tld文件(wpabbs.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>1.0</tlibversion><jspversion>1.1</jspversion><shortname>wpabbs</shortname><uri>http://jakarta.apache.org/struts/tags-wpabbs</uri>

<tag> <name>MyDate</name> <tagclass>com.MyDateTag</tagclass> <bodycontent>empty</bodycontent> <info> Display Date </info></tag>

</taglib>

===========================================================

在web.xml中配置：

部分代码已省略

<taglib> <taglib-uri>/WEB-INF/wpabbs</taglib-uri> <taglib-location>/WEB-INF/wpabbs.tld</taglib-location></taglib>

===========================================================

在jsp页面使用：

<%@ page language="java" pageEncoding="UTF-8"%>

<%@ taglib uri="/WEB-INF/struts-bean" prefix="bean" %><%@ taglib uri="/WEB-INF/struts-html" prefix="html" %><%@ taglib uri="/WEB-INF/struts-logic" prefix="logic" %><%@ taglib uri="/WEB-INF/wpabbs" prefix="wpabbs" %>

<wpabbs:MyDate/>

输出结果：

今天是2008年6月22日,星期日