How to use custom tags in javaweb programs (tag, TLD two kinds) __java

TLD Definition Format

<?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> <!--definition Tag version library--> <tlib-version>1.0</tlib-version> <!--definition JSP version library--> <jsp-version>1.2</jsp-version> <short-name>cms tag</short-name> < description><!--Tag Description---> A simple appbase Tag library </description> <tag> <name>page</ name><!--Tag's name--> <tag-class>com.cms.common.tag.PageTag</tag-class><!-- Tag corresponding Java class name--> <body-content>empty</body-content> <!--about Body-content has three values optional; empty: The label body must be empty; JSP: Tags are composed of other JSP elements, such as tags containing <%=attributeName%> jsp elements, then body-content value is the actual AttributeName incoming value; Tagdependent: There are tag explanations without JSP conversions (this deep meaning is not very well known)--> <attribute><!---Here is a parameter for this tag--> <name>cmsform</name> <!--the name of this parameter--> <required>true</required><!--whetheris a required option--> <rtexprvalue>true</rtexprvalue><!--Whether the value of this parameter can be written, in other words, whether this parameter can be dynamically assigned--> </
 Attribute> </tag> </taglib>

define tag corresponding class

This class must override doStartTag and Doendtag methods

/**
 * * * * * *
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 ("This is my tag example <br/>" + "Cmsform:" +this.cmsform);
		} catch (Exception e) {
			//Todo:handle Exception
			e.printstacktrace ();
		}
		Return super. Eval_page
	}
}

add taglib corresponding file configuration in Web.xml

Such as:

<taglib>
<taglib-uri>http://mytag.sf.net</taglib-uri>
<taglib-location>/ Web-inf/mytag.tld</taglib-location>
</taglib>

This means that the http://mytag.sf.net corresponds to the Web-inf/mytag.tld file

referencing in JSP pages

Such as:

<%@ taglib uri= "http://mytag.sf.net" prefix= "MyTag"%>

using in JSP pages

<myTag:exname1><myTag:exname1>

Example:

Define MYTAG.TLD label file

<?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-jspta Glibrary_1_1.dtd "> <taglib> <tlibversion>1.0</tlibversion> <jspversion>1.1</ jspversion> <shortname>myjsptag library</shortname> <uri>http://mytag.sf.net</uri> < info> my sample Tag library </info> <tag> <name>demo. Viewport</name> <tagclass>com.myapp.web.tag.DemoViewTag</tagclass> <bodycontent>jsp</ Bodycontent> <info>demo. Viewport tags </info> <attribute> <name>northTitle</name> &LT;REQUIRED&GT;TRUE&LT;/REQUIRED&G
			T <rtexprvalue>true</rtexprvalue> </attribute> <attribute> <name>westtitle</name&
			Gt
<required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib> 

Defining label Classes

/** * * * * * * 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 SE
	Rialversionuid = 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 ("This is my tag example <br/>westtitle:" +this.westtitle+ "<br/>northtitle:" +this.northtitle); catch (excEption e) {//Todo:handle exception e.printstacktrace (); Return super.
	Eval_page;
 }
}

Web.xml Add Configuration

<taglib>
<taglib-uri>http://mytag.sf.net</taglib-uri>
<taglib-location>/ Web-inf/mytag.tld</taglib-location>
</taglib>

test Page

<%@ 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" >