JDBC and insert - stack overflow

Hi,
I am afraid I am a newbie. Forgive me if this is a silly question-
I'm trying to create a large database using JDBC to load the tables by
calling executeUpdate with the statement "SQL INSERT INTO" + tableName +
" VALUES (" etc...

After 14 and a half thousand rows the java virtual machine crashes with:

Exception in thread "main" java.lang.StackOverflowError
at java.lang.Class.newInstance0(Native Method)
at java.lang.Class.newInstance(Compiled Code)
at sun.io.Converters.newConverter(Compiled Code)
at sun.io.Converters.newDefaultConverter(Compiled Code)
at sun.io.ByteToCharConverter.getDefault(Compiled Code)
at java.lang.String.<init>(Compiled Code)
at postgresql.PG_Stream.ReceiveString(Compiled Code)
at postgresql.Connection.ExecSQL(Compiled Code)
at postgresql.Statement.execute(Compiled Code)
at postgresql.Statement.executeUpdate(Compiled Code)

My first question is:
Am I doing things in a really stupid way?

If not, how do I fix the problem - I have tried increasing the default
stack and memory size for the JVM...
Crispin