JSTL-JSP Standard Tag Library part 2

Evolution of JSTL-JSP Standard Tag Library

As JSP grew in popularity, it became clear that different sites' custom tags fell into familiar, frequently used patterns. For example, many pages needed to loop over data to print tables and lists.

Vendors of JSP containers and members of the open-source community tried to address these needs by providing collections of tags --tag libraries--that solved common problems.

While many JSP page authors used these libraries, nothing tied them together.

To address this fragmentation, the Java Community Process --the same group that now maintains and standardizes JSP itself --decided to offer a standard tag library. JSTL 1.0, to include tags for the following common tasks:

•Looping over data to produce tables, lists, etc.

•Conditional operations

•Importing and processing data from other web pages

•Simple XML manipulation

•Database access

•Text formatting and internationalization

Java Standard Tag Library (JSTL):

JSTL allows us to write JSP pages using tags, rather than the scriptletcode

JSTL is broadly divided into two sections,

1. Tag Attributes

2. Expression Language

1. JSTL provides standard tag libraries into four groups

1. core

2. XML

3. Internationalization/format

4. SQL

2. Expression Language :

EL was introduced in JSTL 1.0, but now is formally defined in JSP 2.0.

The primary design goal for JSTL and the EL (Expression Language) is to simplify webpage development and implementation.

Download Java Standard Tag Library (JSTL):

The current version is JSTL 1.2.

The older version of JSTL are : JSTL 1.0 and JSTL 1.1.

JSTL 1.2 consists of two files:

1. jstl-impl-1.2.jar

2. jstl-api-1.2.jar

These 2 files are combined into jstl-1.2.jarfile. Download the jar file from http://jstl.java.net/download.html

The above jar filesare applicable for JSP 2.1 containers such Tomcat 6.

Apache Tomcat 7 supports Java Servlet 3.0, Java Server Pages 2.2 and Expression Language 2.2specifications.

JSTL is by default not available in Tomcat, So copy jstl-1.2.jar file into Tomcat /lib folder.

Ex. C:\apache-tomcat-7.0.29\lib

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