GWT 2.5 dev mode unable to refresh

[Ben St. Pierre]

Hi guys,

After upgrading to to GWT 2.5 I am unable to refresh my dev mode.  It initially loads fine but reloading (in any browser causes the rpc mechanism to throw this error...

Caused by: com.google.gwt.user.client.rpc.SerializationException: java.lang.RuntimeException: Unable to find class com.google.gwt.user.client.rpc.core.java.util.ArrayList_FieldSerializer

Any idea what would cause this?  As I said again it loads the first time in dev mode but then fails after a refresh (even with no code changes).

[Ben St. Pierre]

No ideas?

[Craig Mitchell]

I've noticed this error when our app opens a new browser window that loads the GWT app up again (not seen the error when refreshing).

Happens in IE9 and Chrome.  However, if I just restart my server and then refresh the page, it will then work okay.

And even more strangely, sometimes the problem doesn't occur at all for days, then it will come back again.

I was trying to figure out if it is because of the generated war/<your app>/*.rpc files, but so far no success.

[Patrick Tucker]

I normally see that right before an out of memory error happens.  I just stop and start the environment and continue on...

[James Nelson]

Have you guys considered trying out the new super-dev-mode?

I only save the sluggish dev mode for when I absolutely have to have a java debugger to find out what's going on.

Super-dev-mode will cost you a few seconds per page refresh (though, OOM popping your JVM is much, much slower),

but it also gets rid of a very nasty class of bugs: "Ones you shouldn't bother with in the first place".

Performance in dev mode and compiled mode are very different,

even down to how asynchronicity and some timing works.

What makes production mode fast makes dev mode slow (jsni).

And, if you have the choice, always optimize for production.

Oh, and in regards to your upgrade woes, make sure you manually delete and gwt unit caches you have left,
a cached unit from one version will likely be incongruent with the new one.

[Craig Mitchell]

fyi: I've now tried super-dev-mode.  It's cool that it is pure JS, but every time I make a change I have to recompile (via the "dev mode on" bookmark), this is really slow as our app is around 2MB of JS (using the gwt plugin I just refresh the page - okay, sometime I have to restart the server).  Also, the Chrome debugger doesn't seem as full featured as the Eclipse debugger.

...but, yes, it does fix the problem.  :-)