Recipe 2.4 Deploying an Individual JSP on Tomcat

Problem

You want to place a JSP file into a web application.

Solution

Copy the new or revised JSP file into the top-level directory of the default Tomcat web application or of another deployed web application.

Discussion

The easiest way to test a new JSP file is to place it at the top level of Tomcat's default web application. This application is located in the <Tomcat-installation-directory>/webapps/ROOT/ directory. Tomcat 4.1.x compiles (or recompiles, if you are pasting a new JSP file over an old one) the JSP and display its response in a web page. You do not have to stop and start Tomcat using the Tomcat manager application for the new JSP file to be available to your web application.

Placing a JSP file in a deployed web application will not work if the JSP depends on application-specific resources such as servlets, custom tags, or other Java classes, because there is no guarantee that the temporary host web application you are using for the JSP has access to those resources.

If you have to deploy a JSP separately from its web application, you can also place a JSP file in a deployed web application other than the Tomcat default application. This makes the JSP page available to application users without having to stop and restart Tomcat. Remember that the JSP files belong in the top level of the web application, which has the following directory structure:

index.html
default.jsp 
anotherJsp.jsp
images/logo.jpeg
WEB-INF/classes/jspservletcookbook/myservlet.class
WEB-INF/lib/helperclasses.jar
WEB-INF/lib/utilities.jar
WEB-INF/web.xml
WEB-INF/mytags.tld

In other words, the top level of the directory contains the HTML and JSP files, as well as the WEB-INF directory. The WEB-INF directory contains:

• The web.xml deployment descriptor

• The classes directory, which contains package-related directories and servlet or support classes like JavaBeans

• The lib directory, which stores any Java Archive (JAR) files containing utility or helper classes that your web application uses

• Optionally, any Tag Library Descriptor files (files with .tld suffixes)

• Any optional directories for images, video files, XML files, or other web resources

See Also

The deployment sections of Tomcat: The Definitive Guide (O'Reilly); Recipe 2.1, Recipe 2.2, and Recipe 2.6.