Mega Code Archive
Tag lifecycle with Attribute
<![CDATA[
<!-- this must be added to the web application's web.xml -->
<taglib>
<taglib-uri>/rntsoft</taglib-uri>
<taglib-location>/WEB-INF/rntsoft.tld</taglib-location>
</taglib>
// create File:rntsoft.tld in the /WEB-INF/
<!DOCTYPE taglib
PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN"
"http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<!-- a tab library descriptor -->
<taglib xmlns="http://java.sun.com/JSP/TagLibraryDescriptor">
<tlib-version>1.0</tlib-version>
<jsp-version>1.2</jsp-version>
<short-name>rntsoft Simple Tags</short-name>
<!-- a tag that outputs information when different methods are called -->
<tag>
<name>tagLifecycle</name>
<tag-class>com.rntsoft.TagLifecycle</tag-class>
<body-content>empty</body-content>
<attribute>
<name>attr1</name>
</attribute>
<attribute>
<name>attr2</name>
</attribute>
</tag>
</taglib>
//compile the following code into WEB-INF\classes\com\rntsoft
package com.rntsoft;
import java.io.IOException;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.Tag;
import javax.servlet.jsp.tagext.TagSupport;
/* This tag handler outputs information about when different methods
are called in the Tag interface.
*/
public class TagLifecycle extends TagSupport
{
// Constructor
public TagLifecycle()
{
System.out.println("TagLifecycle constructor called");
}
// Methods inherited from TagSupport
public void setPageContext(PageContext p)
{
super.setPageContext(p);
System.out.println("setPageContext() called (" + p + ")");
}
public void setParent(Tag t)
{
super.setParent(t);
System.out.println("setParent() called (" + t + ")");
}
public Tag getParent()
{
System.out.println("getParent() called");
return super.getParent();
}
public void release()
{
System.out.println("release() called");
}
// Code to implement the "attr1" attribute
private String attr1;
public String getAttr1()
{
return attr1;
}
public void setAttr1(String s)
{
System.out.println("setAttr1() called with value " + s);
attr1 = s;
}
// Code to implement the "attr2" attribute
private String attr2;
public String getAttr2()
{
return attr2;
}
public void setAttr2(String s)
{
System.out.println("setAttr2() called with value " + s);
attr2 = s;
}
public int doStartTag() throws JspException
{
System.out.println("doStartTag() called");
return SKIP_BODY;
}
public int doEndTag() throws JspException
{
System.out.println("doEndTag() called");
return super.doEndTag();
}
}
// start comcat and load the following jsp page in browser
<%@ taglib uri="/rntsoft" prefix="rntsoft" %>
<html>
<head>
<title>The lifecycle of the Tag interface</title>
</head>
<body>
<rntsoft:tagLifecycle attr1="Joe" attr2="Greenhough" />
<rntsoft:tagLifecycle attr1="Rob" attr2="Greenhough" />
Check the Tomcat console for the output
</body>
</html>
]]>