JalistoPlus is lightweight, transactional, 100% pure Java database. It is object oriented and is able to directly persist and query for Java object graphs.
The core module performs basic persistence operations (create, update, delete, read) and cooperates with other modules - query engine, pluggable cache and disk access layer.
The query engine selects object instances using specified criteria. It offers a standard set of operators (in example: equal, smaller, greater, not, and, or) to build the filter expression. Optionally indexes may be defined on persistent fields to speed up query execution time.
Pluggable disk access layer is fast native solution to read and write data on disk. It comes in two major variants: without transaction log and with transaction log. The log mechanism offers fault-tolerance (ACID transactions). Also a memory backed storage may be used.
JalistoPlus may be used either in single or multi-threaded mode. It is best suited for lightweight applications as it may be directly embedded in them.
JalistoPlus is free and open source. It is available on LGPL license.
JalistoPlus is based on the original Jalisto database still available here, released in 2005 but abandoned since then.