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Accessing a Database with the JSTL 1.1 SQL Tag Library
by Deepak Vohra
Suppose you need to access a database from a JSP page. Without a tag library, you would use JDBC code embedded in scriptlets to access the database. However, a JSP page with HTML and tag library tags is easier to read than a JSP page with scriptlets intermixed with HTML tags. Moreover, you would have to be familiar with the JDBC API. Plus, you don't have to create a custom tag library in order to access a database. Enter JSTL.
The JavaServer Pages Standard Tag Library (JSTL) provides core tags for common structural tasks such as iteration and conditional processing, XML tags for XML processing, internationalization tags for formatting, and SQL tags for database processing. This article discusses the JSTL SQL tags for database access. Jakarta Taglibs provide the Standard Taglib 1.1, an implementation of the JSTL 1.1.
You'll see how to install the Standard Taglib 1.1 in a WebLogic server 9.0, which supports the Servlet 2.4 and JSP 2.0 specifications (Standard 1.1 requires a JSP container that supports these specifications). You'll use these to develop a JSP application which retrieves data from a database using JSTL SQL tags and displays that data in a table.
Preliminary Setup
You will need the following installed on your computer:
- Jakarta Taglibs Standard Taglib 1.1
- WebLogic server 9.0
- MySQL Database Server
- MySQL JDBC driver Connector/J
Add the JSTL TLDs and JAR files to a sample Web application in WebLogic server (another application server which supports the J2EE 1.4 specifications may also be used). Copy c.tld and sql.tld from the <jakarta-taglibs-standard-1.1.2
>\tld directory to the <weblogic91>/samples/server/examples/build/mainWebApp/WEB-INF directory. <weblogic91> is the directory in which WebLogic Server 9.1 is installed. Create a lib directory in the WEB-INF directory and copy jstl.jar and standard.jar from the <jakarta-taglibs-standard-1.1.2>\lib directory to the lib directory. Next, add the JSTL 1.1 JAR files to the WebLogic server classpath. Add jstl.jar and standard.jar to the CLASSPATH variable in the <weblogic91>/samples/domains/wl_server/bin/startWebLogic script CLASSPATH variable. Also add the MySQL JDBC .jar file to the startWebLogic script CLASSPATH variable.
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