JSP Tutorials - Herong's Tutorial Examples - v5.11, by Herong Yang
Creating and Using Custom Tags
This section describes main steps of creating and using custom tags in JSP pages. Each custom tag is supported by a Java tag class that extends the javax.servlet.jsp.tagext.TagSupport class.
Main steps of creating and using a custom tag:
1. Writing the Java tag class using javax.servlet.jsp.tagext.TagSupport as the base class. Here how a tag class, TestTag.java, looks like:
import javax.servlet.jsp.tagext.*;
public class TestTag extends TagSupport {
public int doStartTag() {...}
public int doEndTag() {...}
...
}
2. Compiling the tag class with the help of the jsp-api.jar provided by the Tomcat server.
3. Installing the compiled tag class to the .\WEB-INF\classes directory on the Tomcat server.
4. Creating the TLD (Tag Library Descriptor) file to define your own tag library with a list of tags and their Java classes. Here is how a TLD file, MyTaglib.tld, looks like:
<?xml version="1.0"?> <taglib> <tlib-version>1</tlib-version> <jsp-version>1.2</jsp-version> <short-name>Herong's Tag Library</short-name> <tag> <name>test</name> <tag-class>TestTag</tag-class> <body-content>empty</body-content> </tag> ... </taglib>
5. Installing the TLD file to the .\WEB-INF\tlds directory on the Tomcat server.
6. Writing a JSP page to use the new custom tag. You need to declare a new namespace for your new TLD file and use the tag as an action element:
<jsp:root xmlns:hy="urn:jsptld:/WEB-INF/tlds/HyTaglib.tld" ...> ... <hy:test/> ...
7. Deploying JSP pages to the Tomcat server. You are ready to visit thoes JSP pages.
Table of Contents
JSP (JavaServer Pages) Overview
Tomcat Installation on Windows Systems
Syntax of JSP Pages and JSP Documents
JavaBean Objects and "useBean" Action Elements
Managing HTTP Response Header Lines
Non-ASCII Characters Support in JSP Pages
Overview of JSTL (JSP Standard Tag Libraries)
►Creating and Using Custom Tags
My First Custom Tag - hy:hello
Multiple Tags Working Together
Using Tomcat on CentOS Systems
Connecting to SQL Server from Servlet