JSP standard tags library can be divided into four tag libraries which are:
- Core tags
- Internationalization (i18l) and formatting tags
- Relational database access tags
- XML processing tags
The goals of those tag library above are:
- Simplify the task of writing JSP page by providing friendly XML base tags
- Provide reusable logic from page's presentation
- Make the JSP page easier to read and maintain
As its name imply, core tags provide the core functionality actions to JSP to make the most common actions easier to achieve in a more effective way. Core tags specify several actions such as displaying content based on condition, manipulating collections and URL managing. By using the core tags you'll never has to write a such small piece of scriptlet. (But you still need to know scriptlet to maintain legacy web applications and convert them to JSTL later on if you have to).
Internationalization(I18L) and formatting tags:
Those tags specify a series actions to make the web application multilingual. Those actions including managing resource bundle, locales and base names.
Relational database access tags:
Accessing database is a most major task of web applications. JSTL provides a list of standard tags to help you to manipulate data such as select, insert, update and delete from the relational databases.
XML processing tags:
XML becomes a standard of enterprise web application for exchanging data. ManipulateXML effectively therefore is very important for most web applications and of course JSTL also provides a list of tags for processing from XML parsing to XML transformation.