java - Disk based HashMap

Question

Does Java have (or is there a library available) that allows me to have a disk based HashMap? It doesn't need to be atomic or anything, but it will be accessed via multiple threads and shouldn't crash if two are accessing the same element at the same time.

Anyone know of anything?

Answer 1

MapDB

MapDB provides concurrent TreeMap and HashMap backed by disk storage or off-heap-memory. It is a fast, scalable and easy to use embedded Java database engine. It is packed with features such as transactions, space efficient serialization, instance cache and transparent compression/encryption. It also has outstanding performance rivaled only by native embedded db engines.

http://www.mapdb.org/

jdbm2

Embedded Key Value Java database.

https://code.google.com/p/jdbm2/