JSTL 1.1.x guide
Updated: 6:31 p.m. EDT, July 15th, 2008Installing JSTL 1.1.x can be tricky. JSTL 1.1.x needs to installed with a compatible version of Tomcat, and needs to be configured correctly for it to work without issues. This guide shows you where to get JSTL 1.1.x from, how to install it, what to check for compatibility along with a few examples to get you started or troubleshoot an existing installation of JSTL.
-
Download JSTL 1.1.x
Get JSTL 1.1.2 from The Jakarta Site - Standard 1.1 Taglib DownloadsOS: Windows 2000, XP, Vista - get 1.1.2.zipOS: Unix, Linux, Mac OS - get 1.1.2.tar.gz
-
Advertisement:
New SOA books. Save 35% plus Free Ground Shipping. Try a FREE SOA eBook. This Promotion Ends August 30th, 2008 -
Install JSTL 1.1.x
OS: Windows 2000, XP, Vista
Unzip 1.1.2.zip to any directory. Example: unzip to C:\dev\ using any ZIP utility.OS: Unix, Linux, Mac OS
Unzip 1.1.2.tar.gz to any directory using the command:
tar -xzffile_name.tar.gz.
Example:
cd /opt
sudo tar -xzf 1.1.2.tar.gz
(sudo is optional, use it only if you get permission denied error. Use sudo and then enter your login password.)
Unzipping the file should create this folder: jakarta-taglibs-standard-1.1.2 in the directory of your choice.
From the jakarta-taglibs-standard-1.1.2 copy : jstl.jar and standard.jar into your project's WEB-INF/lib folder. Just these two JAR files are sufficient.
The official JSTL documentation is this folder: \jakarta-taglibs-standard-1.1.2\doc\index.html and GettingStarted.html This documentation has useful information about dependencies etc, it is always a good place to refer to when something doesn't work. -
Configure JSTL 1.1.x
This version of JSTL does not require any further configuration. See compatibility and depedency for more information. -
JSTL 1.1.x Compatibility
JSTL 1.1.x requires a Web Server (Container) that complies with the Servlet 2.4 / JSP 2.0 (or higher) specification.
For example: Tomcat 5.5.x complies with Servlet 2.4 and JSP 2.0 specifications.
See: Tomcat Version - Servlet Spec - JSP Spec chart
This also means that the deployment descriptor (web.xml file under your project's WEB-INF) folder must also comply with the Servlet 2.4 specification. This means that the web-app declartion and all the tags inside web.xml must be according to the Servlet 2.4 specification.
In a nutshell JSTL 1.1.2 is compatible with EL, JSP 2.0, Servlet 2.4.
Note that the EL in JSP 2.0 is not compatible with the EL in JSF 1.1 or 1.2.
If you are working with JSF 1.2 or higher then upgrade from JSTL 1.1.x to JSTL 1.2 because it supports Unified EL, along with a Web Container that is compatible with JSP 2.1 and Servlet 2.5.<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4"> </web-app> -
JSTL 1.1.x Dependency
JSTL 1.1.x comes with various tags that serve different purposes. Depending on which tags you plan to use you will need certain dependencies.
You don't need any other dependencies if you plan to use just the core, format, function tags or just EL (expression language).
If you plan to use the sql tags then you'll need the JDBC connector JAR file for your database. You can place this connector JAR in your web container's lib folder.
If you plan to use the xml tags then you'll need Xalan.jar, Serializer.jar.
If I've missed any other dependencies, then you'll get an exception error message such as "ClassNotFound", "Method Not Found" etc, examine the exception, to find out which package the class or method belongs to and then search for the distributions containing those class or method files. Get the distribution version that is compatible with the JSTL version you are using.
Read the documentation found under: \jakarta-taglibs-standard-1.1.2\doc\index.html and GettingStarted.html of the distribution, for dependency information. -
JSTL 1.1.x Usage Guide
The tag library you plan to use must be defined in each JSP page the tags appear on. If you are familiar with XML terminology this is known as name space declartion. By declaring a namespace prefix of say "c"and associating it with a taglib URI, you are basically indicating that all tags that start with c: are JSTL core tags.
The taglib URIs are different across different versions of JSTL. Make sure that the taglib URIs you use in the JSP files match with the JSTL version you are using.
To see JSTL 1.1.x the taglib URIs, click on the tag library of your choice. For example see the core taglib URI.
JSTL core:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
JSTL fmt:
<%@ taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
JSTL sql:
<%@ taglib prefix="sql" uri="http://java.sun.com/jsp/jstl/sql" %>
JSTL XML:
<%@ taglib prefix="x" uri="http://java.sun.com/jsp/jstl/xml" %>
JSTL Functions:
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %> -
JSTL 1.1.x Examples
JSTL is very powerful and flexible. There are more than one ways to accomplish the same outcome.
JSTL 1.1.x core tags
Set the value of a variable:
<c:set var="myVariable" value="Hello World!"/>
Display the value of a variable:
<c:out var="${myVariable}"/>
Display the value of a variable and escape all XML entities:
<c:out var="${myVariable}" escapeXml="true"/>
JSTL 1.1.x EL (expression language)
Without declaring any JSTL tags it is possible to write some Expression Language which produces the same effect as the core tags, except that the syntax is much more terse:
Display the value of a variable:
${myVariable}
If you import the functions tag lib then you can get additional functionality with EL, that is similar to the core tags, again with a shorter syntax.
Display the value of a variable and escape all XML entities:
${fn:escapeXml(myVariable)} -
Troubleshoot JSTL 1.1.x
EL is not evaluating
If the EL does not evaluate this is most likely a compatibility issue. If you are upgrading from a previous version of JSTL it is recommended that you start fresh on a clean slate. Verify that the Web Container and your deployment descriptor (web.xml) is compatible with Servlet Specification 2.4 or higher. See compatibility for more details.
The absolute uri: http://java.sun.com/jsp/jstl/core cannot be resolved in either web.xml or the jar files deployed with this application
If you get the above error, it is most likely due to a missing standard.jar file. Copy the standard.jar file that came with the JSTL distribution to your project's WEB-INF/lib folder. Restart your web container and test again. -
Advantages of JSTL
- JSTL is a front end technology that offers an HTML/XML tag like syntax, which blends well with the standard HTML tags.
- JSTL and EL are very flexible and offer a variety of ways to interact with other technologies sucy as XML, XSLT, SQL.
- In a model-view-controller (MVC) framework, JSTL tags would be the view layer, they offer a clean separation of concerns. The only exception would be SQL tags. Try to use the SQL tags only for quick prototyping. In an industrial application, move the SQL to the DAO layer.
Books:
Core JSTL: Mastering the JSP Standard Tag Library (Core Series) (Paperback - Dec 6, 2002).
Master web programming with MVC, Tomcat, JSP, Servlets, JSTL, EL, JDBC, connection pooling and more.
JSTL in Action (Paperback - Jul 2002).
Tutorial style, easy for beginners.
Books:
References:
- JSTL 1.1.x API
- Latest news on JSTL 1.1.x / Standard Taglib 1.1: http://jakarta.apache.org/taglibs/doc/standard-doc/intro.html
- JSTL 1.1.x Documentation: http://jakarta.apache.org/taglibs/doc/standard-doc/standard/index.html
- JSTL 1.1.x Getting Started: http://jakarta.apache.org/taglibs/doc/standard-doc/standard/GettingStarted.html
- JSTL 1.1 Specification (Maintenance Release) - PDF document.
- EL Specification (Final Release) - PDF document.
- Servlet 2.4 Specification Final Release : http://java.sun.com/products/servlet/download.html
- JSP 2.0 Specification Final Release : http://java.sun.com/products/jsp/reference/api/index.html
- JSP 2.0 Tags Syntax Reference
- Tag Libraries Tutorial
- JSTL 1.1 Tutorial
- MVC Design Pattern
- Core J2EE Patterns
Related:
