Question

I have an application that has the following structure

$TOMCAT_HOME/webapps/myapp
            |-css
                |-myapp.css
            |-js
                |-myapp.js
            |-forum
                |-index.jsp
                |-list.jsp
                |-users.jsp
            |-Articles
                |-index.jsp
                |-ListArticles.jsp
            |-Guestbook
                |-viewGuestBook.jsp
                |-AddnewEntry.jsp
            |-WEB-INF
                |-classes
                    com
                     |-myapp
                        |-forum
                            |-DisplayForum.class
                            |-ListUsers.class
                        |-article
                            |-ArticleList.class
                            |-AddArticle.class
                        |-guestbk
                            |-LoadGuestBook.class
                            |-ProcessGuestBook.class

The application is delivered as a war file (i.e. myapp.war) and is deployed into the $TOMCAT_HOME/webapps folder. If any of the files change (either the jsp, css, js or java files) i have to always rebuild the whole war file. This means i deploy every single file on every release.

I am wondering if there is a way to deploy specific areas of the application. I am particularly interested if it is possible to separate the application into multiple war files. i.e. myapp.war, articles.war and forum.war. I would like to still access the application via the same context i.e. http://0.0.0.0/myapp even though multiple war files are used.

Using this approach, i will be able to deliver just the module that was affected by the change. Is this at all possible?

I dont mind having to restart the container after each war file is deployed.

Answer 1

I don’t remember how you do this is Tomcat exactly, you’ll probably have to do some manual configuration (in context.xml or something like that) but I’m fairly certain you can deploy your three applications (.wars) with the following context paths:

• myapp.war -> /myapp
• articles.war -> /myapp/articles
• forum.war -> /myapp/forum

I’ve found a bit of information specific to Tomcat here:

http://tomcat.apache.org/tomcat-6.0-doc/config/context.html

Specifically:

In individual files (with a “.xml” extension) in the
$CATALINA_BASE/conf/[enginename]/[hostname]/ directory. The name of
the file (less the .xml extension) will be used as the context path.
Multi-level context paths may be defined using #, e.g. foo#bar.xml for
a context path of /foo/bar. The default web application may be defined
by using a file called ROOT.xml.

Alternatively, you may want to do something like:

• myapp.war -> / (by calling it ROOT.war)
• articles.war -> /articles
• forum.war -> /forum

Having said that, keep in mind that if you do this, you’ll not be able to have shared state (session information) between the three applications without some effort. For instance, if “forum.war” requires authentication, that authentication information will not be available to myapp.war or articles.war.