What Is Custom Tag

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∟What Is Custom Tag

This section describes what is JSP custom tag. A custom tag can be define by the user through the JSP tag extension facility using a Java tag class.

What Is Custom Tag? Custom Tag is an action tag defined by the user through the JSP tag extension facility. It can be used to move JSP scripting code and information into a Java tag class, and invoke it by an action tag that is linked to that class. There are two main advantages of using custom tags:

Repeatable JSP page logics and information can be simplified and centralized into a single tag. For example, we can define a custom tag called <my:copyright/> for producing the copyright information that need to be used on every page of a JSP application.
Moving complex business logics from the JSP to a tag class, so the JSP page author can concentrate on the presentation logics only. For example, we can define a custom tag called <my:userList/> for producing a HTML table filled with a list of users. The tag class will manage how to put each user into a row, and each user property into a column.

I am sure that the functionalities provided by custom tags can also be archived by using JavaBean and scripting elements together. But tags seem to be simpler to use for many unsophisticated JSP page authors.