Components That Make Up a 

Tag Library

The Tag Handler Class

Must implement javax.servlet.jsp.tagext.Tag 

Usually extends TagSupport or BodyTagSupport

Goes in same directories as servlet class files and beans

The Tag Library Descriptor File

XML file describing tag name, attributes, and 

implementing tag handler class

Goes with JSP file or at arbitrary URL

The JSP File

Imports a tag library (referencing descriptor file)

Defines tag prefix

Uses tags

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JSP

www.corewebprogramming.com

Defining a Simple Tag Handler 

Class

Extend the TagSupport class

Import needed packages

import javax.servlet.jsp.*;

import javax.servlet.jsp.tagext.*;

import java.io.*;

Override doStartTag

Obtain the JspWriter by means of pageContext.getOut()

Use the JspWriter to generate JSP content

Return SKIP_BODY

Translated into servlet code at page translation time

Code gets called at request time

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JSP

www.corewebprogramming.com

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