Separating war application name from war file name

Question

Currently if i deploy a war file on tomcat named say myapp.war, I can access its url by http://localhost/myapp/MyServlet.

However what I want is to deploy a war with a version number in the war file name and still have the same url. For eg, I want to deploy myapp-1.1.0.war and still have the url be http://localhost/myapp/MyServlet

Of course I need to keep updating the war and the version number will keep changing, so I cant hardcode the war filename anywhere. Is there any setting in web.xml I can use to keep the same url for the app regardless of the war filename?

Solution 1

The solution is to stop using the automatic deployment feature of Tomcat, which takes the shortcut of setting the "context name" (the /myapp part of the URL) to the portion of the WAR filename before ".war".

Instead, extract the WAR contents to the filesystem yourself and setup an XML file at TOMCAT_HOME/conf/[enginename]/[hostname]/[contextname].xml which points the desired context path (such as /myapp) to the location of the application on disk (such as /opt/webapps/myapp-1.1.0/).

The Tomcat reference docs provide a good explanation of how Tomcat deploys applications automatically, and how you can configure customized logic for the mapping of context path to application file location (there are a handful of alternate ways to set this up other than the one I suggest above).

Solution 2

You can use YOUR_WAR/META-INF/context.xml for this. Here is a sample:

<?xml version="1.0" encoding="UTF-8"?>
<Context antiJARLocking="true" path="/MyServlet"/>

Solution 3

When using Maven you can control your deployment's path by doing the followings:

Tomcat's conf/tomcat-users.xml:

<tomcat-users>
  <role rolename="manager-gui"/>
  <role rolename="manager-script"/>
  <role rolename="manager-jmx"/>
  <role rolename="manager-status"/>
  <role rolename="admin-gui"/>
  <role rolename="admin-script"/>

  <user username="root" password="root" roles="manager-gui,manager-script,manager-jmx,manager-status,admin-gui,admin-script"/>

</tomcat-users>

~/.m2/settings.xml :

...
<server>
  <id>tomcat</id>
  <username>root</username>
  <password>root</password>
</server>
...

pom.xml :

...
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.example</groupId>
  <artifactId>myapp</artifactId>
  <version>1.1.0</version>
  <packaging>war</packaging>
...
  <build>
    <plugins>
      <plugin>
        <groupId>org.codehaus.mojo</groupId>
        <artifactId>tomcat-maven-plugin</artifactId>
        <configuration>
          <!-- neglect /html below Tomcat7: -->
          <url>http://server:8080/manager/html</url>
          <!-- Refer to the server settings in your ~/.m2/settings.xml -->
          <server>tomcat</server>
          <path>/myWebApp</path>
        </configuration>
      </plugin>
      ....
    </plugins>
  </build>
...

Start your tomcat first Then build and deploy your application..

mvn clean install tomcat:deploy

..it will be accessible under http://server:8080/myWebApp

Solution 4

There is no setting in web.xml for this. I do not believe that it is possible to set this inside the war file in a cross-container way - there is no mention of it in the spec anyway - so each container does it differently. jboss-web.xml, sun-web.xml, context.xml etc.

Solution 5

I prefer to use "##" symbols for noting version of *.war files in the tomcat.
For example:
myapp.war -> URL: http://localhost:8080/myapp/MyServlet
myapp##1.1.0 -> URL: http://localhost:8080/myapp/MyServlet (still the same, because all symbols after "##" are ignoring by tomcat)

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