If you have access to the server you can explode the WAR to a separate directory (using
jar -xf application.war) and then add the web-app to the Tomcat instance
For example - if your application were called "my-app" you would create a file within
TOMCAT_ROOT/conf/Catalina/localhost/my-app.xml which contained details of the application. For a very simple application this might just be something like:
You might also have more complicated configuration (such as database connection parameters, etc.) within here.
If you then want to redeploy the application after you've changed an individual object (JSP, image, etc.) you can use the manager app to redeploy without having to restart the whole Tomcat environment.