Create your own tag: a custom tag body : Tag « JSP « Java
Create your own tag: a custom tag body
///
<!-- this must be added to the web application's web.xml -->
<taglib>
<taglib-uri>/java2s</taglib-uri>
<taglib-location>/WEB-INF/java2s.tld</taglib-location>
</taglib>
// create File:java2s.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>Java2s Simple Tags</short-name>
<!-- this tag manipulates its body content by converting it to upper case
-->
<tag>
<name>bodyContentTag</name>
<tag-class>com.java2s.BodyContentTag</tag-class>
<body-content>JSP</body-content>
<attribute>
<name>howMany</name>
</attribute>
</tag>
</taglib>
//compile the following code into WEB-INF\classes\com\java2s
package com.java2s;
import java.io.IOException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.BodyContent;
import javax.servlet.jsp.tagext.BodyTagSupport;
public class BodyContentTag extends BodyTagSupport
{
private int iterations, howMany;
public void setHowMany(int i)
{
this.howMany = i;
}
public void setBodyContent(BodyContent bc)
{
super.setBodyContent(bc);
System.out.println("BodyContent = '" + bc.getString() + "'");
}
public int doAfterBody()
{
try
{
BodyContent bodyContent = super.getBodyContent();
String bodyString = bodyContent.getString();
JspWriter out = bodyContent.getEnclosingWriter();
if ( iterations % 2 == 0 )
out.print(bodyString.toLowerCase());
else
out.print(bodyString.toUpperCase());
iterations++;
bodyContent.clear(); // empty buffer for next evaluation
}
catch (IOException e)
{
System.out.println("Error in BodyContentTag.doAfterBody()" + e.getMessage());
e.printStackTrace();
} // end of catch
int retValue = SKIP_BODY;
if ( iterations < howMany )
retValue = EVAL_BODY_AGAIN;
return retValue;
}
}
// start comcat and load the bodyContent.jsp in browser
<%@ taglib uri="/java2s" prefix="java2s" %>
<html>
<head>
<title>A custom tag: body content</title>
</head>
<body>
This page uses a custom tag manipulates its body content.
Here is its output:
<ol>
<java2s:bodyContentTag howMany="3">
<li>java2s.com</li>
</java2s:bodyContentTag>
</ol>
</body>
</html>
