how to use and create JSP (Java Server Pages) Custom tag
JSP (Java Server Pages) Custom tag
JSP (Java server pages) custom tags separate
the program logic and presentation of tag. Application designer uses the JSP
custom tags in JSP page. Application developer develops the logic of custom
tag. Lets begin on how to create and use JSP custom tags.
Use of JSP custom tag
1. JSP
custom tag use in JSP page
2. It
reduces coding in JSP pages.
3. Application
designer easily work on JSP pages
4. It
is reusable
Steps for creating JSP tag
1. Create
the tag handler class
2. Create
the TLD (Tag library descriptor)file
3. Create
the JSP file.
Packaging
Root
directory (Current_Date_and_Time)
Directory (WEB-INF)
Directory (classes)
Tag
handler class(MyTag.class)
Directory (src)
Tag
handler java file(MyTag.java)
TLD file(mydate.tld)
JSP file(index.jsp)
Example
Print
current date and time
Tag handler class
MyTag.java
package abc;
import java.io.*;
import javax.servlet.jsp.*;
import
javax.servlet.jsp.tagext.*;
import java.util.Calendar;
public class MyTag
implements Tag
{
PageContext pagecontext;
Tag parent;
public void setPageContext(PageContext pagecontext)
{
this.pagecontext=pagecontext;
}
public void setParent(Tag p)
{
parent=p;
}
public Tag getParent()
{
return parent;
}
public int doStartTag() throws JspException
{
try
{
JspWriter
out=pagecontext.getOut();
Calendar
cal=Calendar.getInstance();
out.print(cal.getTime());//print
date and time
}
catch(IOException e)
{
System.out.println(e);
}
return SKIP_BODY;
}
public int doEndTag() throws JspException
{
return EVAL_PAGE;
}
public void release()
{
}
}
Copy this code and paste into MyTag.java file.
TLD file
Mydate.tld
<taglib>
<tlibversion>1.0</tlibversion>
<jspversion>2.1</jspversion>
<tag>
<name>date</name>
<tagclass>abc.MyTag</tagclass>
</tag>
</taglib>
Copy this code and paste into mydate.tld file
JSP
file
Index.jsp
<%@ taglib
uri="/WEB-INF/mydate.tld" prefix="my" %>
<html>
<head>
</head>
<body>
<h3>Current date and time</h3>
<my:date></my:date>
</body>
</html>
Copy this code and paste into index.jsp file
Output
!----------------------------------------------------Huntertech-------------------------------------------------------!
Team
www.bel-technology.com
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