I'm developing a web app in Dart, packaged in tomcat 6 as a deployable .war. This app is used by a bunch of clients, all with Google Chrome.
Every time I republish a new version, every single client must clear his browser cache before seeing the updated files: this is very annoying and I can't find any solution other than broadcast a mail to everyone "Please clear the browser cache".
The desirable solution is not a complete cache disable but that the browser keeps caching all stuff to be the quicker it could, and that I can control this at my wish.
I'm not sure what your question is about exactly. There is nothing specific to Dart. Caching is handled by the browser depending on the expires headers the server returns with a response to a request.
What you can do is something like explained here Force browser to clear cache or Forcing cache expiration from a JavaScript file, and make the client application poll the server frequently for updates and then redirect to the new URL. You could implement some kind of redirection on the server or ignore the version URL query parameter, to be able to actually keep the same names of the resources.
Another possibility could be to use AppCache and serve the manifest file with immediate expiration. When you have an updated version modify the manifest file which makes the client reload the resources listed in the manifest (https://stackoverflow.com/a/13107058/217408, https://developer.mozilla.org/en-US/docs/Web/HTML/Using_the_application_cache, http://alistapart.com/article/application-cache-is-a-douchebag#section4).