Oracle Berkeley DB Java Edition

Oracle Berkeley DB Java Edition is an open source, embeddable, transactional storage engine written entirely in Java. It takes full advantage of the Java environment to simplify development and deployment. The architecture of Oracle Berkeley DB Java Edition supports very high performance and concurrency for both read-intensive and write-intensive workloads. Depending on your needs choose between Berkeley DB Java Edition's Direct Persistence Layer (DPL), Persistent Collections API, or simply store key/value pairs of arbitrary data. If your application requires something outside the bounds of relational databases then Berkeley DB Java Edition is likely to be the best choice.