Spring PetClinic comes with a HsqlDB (1.8.0) database. It is easy to start, just change directory to spring/samples/petclinic/db/hsqldb and start server.sh or server.cmd.
I was just fiddling around and for some strange reason I happened to telnet to the running database. I issued two commands, well to be exact I pressed two times the enter key in the session. BOOOM!
Exception in thread "HSQLDB Connection @1a457b6" java.lang.OutOfMemoryError: Java heap space
at org.hsqldb.lib.HsqlByteArrayOutputStream.reset(Unknown Source)
at org.hsqldb.rowio.RowOutputBinary.reset(Unknown Source)
at org.hsqldb.rowio.RowInputBinary.resetRow(Unknown Source)
at org.hsqldb.Result.read(Unknown Source)
at org.hsqldb.ServerConnection.init(Unknown Source)
at org.hsqldb.ServerConnection.run(Unknown Source)
at java.lang.Thread.run(Thread.java:619)
I launched the instance again and retook the steps. BOOOM! I tested it also with the Aranea Framework sample database (don’t know the version) and it was reproducible there as well.
This is not of course a big issue as HsqlDB is just a lightweight bundled database that hopefully nobody uses on a remote interface or otherwise BOOM!