If it's the shared memory in the database, and the Java process is not a Java stored proc, then it's not the Java running out of memory (sorry, Ross, you're full of crap :-). Oracle requires a lot of shared memory to run properly - it's used for many different things. Java may be trying to create a prepared statement on the fly, and Oracle is running out of memory trying to parse it because too many other things are using the shared memory at the moment.

I swear by my beard, I've seen non-stored-proc Java eat enormous chunks of RAM, with a starting point at 200M. Of course, it may have been shitty Java. This was not DB mem - this app was started on its own from a shell script and every VM started ate a huge gulp of its own RAM. This app did have a huge amount of logic in it, but no more than a typical large-scale business app of yore.

(Thinking back on this, I know why it needed such huge amounts of RAM. The purpose of the app was to route bank requests from any number of places to any number of other places as fast as possible, with a huge queue of requests possible - projected as many as tens of thousands per second - credit card transactions - and this app needed to build a huge tree structure to figure out an efficient route. That's a theory. I didn't write it :)