Setting up HSQLDB I used version 1.7.3.0 of HSQLDB. To use an in-memory version of the database you need to invoke the static loader for the org.hsqldb.jdbcDriver. Then when you get a JDBC connection ...

HSQLDB JDBC tutorial prerequisites For this tutorial we will use Eclipse and Maven, but the process is the same for other build tools and IDEs. The steps performed in this JDBC with HSQLDB tutorial ...

This blog shows how such an application can be created using Grails, hosted on built-in Jetty servlet engine and use in-memory HSQLDB database for persistence.

HSQLDB is a lightweight SQL database, which appeared originally as HSQL, and was focused on "in memory" operations. It forked to become HSQLDB and developed a persistent on-disk mode.