Java Server Page

Custom Tag is Used for define some custom action in JSP page/file and collection of custom Tag is called library.Custom Tag have encapsulate recurring task( or abstract method ) because they can used across more than one application and JSP page.

Main Purpose of JSP tag libraries ( especially custom tag ) is one time developed in Java programming language and used most of Web application designer, where major focus is presentation issue rather than being concerned about Java code and how to access databases and other enterprise services.Some main features of custom tags are:

• Important thing about Tag is they can easily communicate each other, rather than JavaBeans and HTTPSession.
• They can easily access to all the object available to any JSP page/file.
• They can be modify according to page demand, and generate response by the calling to JSP page.
• They can be nested within each other another, allowing for complex interactions within a JSP page.
• Due to encryption of method easily access to package to another package, any where in JSP page.