I have big problems with the Vaadin plugin. My Eclipse is Version: Helios Service Release 2 / Build id: 20110301-1815
I create a Vaadin project
I select Debug as - Debug on server, I select my Tomcat and click finish
Now a browser window comes up in Eclipse with HTTP status 404
Now I go to the servers window and restart my Tomcat in debug
I refresh the browser window and see “Hello Vaadin user”
Not a big problem, but when I change the Java code and save the file, the browser content does not change.
It changes for the same URL in an external browser, but only once???
Where is my mistake? My server configurations are plain Tomcat 5.5, 6, or 7. I have tried all.
Add “?restartApplication” to your URL and/or disable session serialization in your development Tomcat instance (see e.g.
this page : uncomment the Manager=“” in the default configuration ).
Otherwise, the code is changed at runtime (if possible through HotSwap, which is quite limited in the JRE) or at server restart, but the server uses an old instance of the application in the session for which the visible parts of the UI has already been built.
In case you keep running against the limits of what HotSwap can do without restarting the server, the commercial product JRebel from ZeroTurnaround can do more changes at runtime.
The reason why the content doesn’t change after Java code changes is because the application instance you have running already isn’t updated, it’s still in the same state as before.
In order to restart the application with a clean state, append the ?restartApplication parameter after the application url.