Resource / download

Jexcelapi
Java Excel is a java API to read, write, and modify Excel spreadsheets
EclipseLink
The Eclipse Persistence Services Project (EclipseLink) delivers a comprehensive open-source Java persistence solution. EclipseLink focuses on standards with advanced features, performance and scalability for enterprise software developers across data sources, formats, and containers.
DB40
db4o is the most powerful and yet simple to use database on the planet. Its power comes from allowing arbitrarily complex, application defined, class models to also represent your database schema. This eliminates time consuming and tedious mapping code and returns wasted mapping CPU processing to the application for raw performance.