You can use the https://github.com/fusesource/leveldbjni java library which gives you a Java API to LevelDB via JNI. There is also a Pure Java implementation of LevelDB available at https://github.com/dain/leveldb Both the JNI wrapped and pure Java implementation implement the same interface classes so it’s really easy to switch between the two.
I would suggest to have a look at LMDB (which is the most efficient engine for OpenLDAP, and used in a number of other open-source projects). LMDB is an embedded key/value store, with a Berkeley-DB or LevelDB like API, does not have to store everything in memory, and can support access from multiple processes. There … Read more
I only add this because in both of the previous answers I don’t see this (important) distinction made… Redis: Is a database server. You communicate with it via a custom binary protocol (via client library typically). LevelDB: Is a library that implements a key-value store. You communicate with it by calling the C++ API directly. … Read more
Keys in leveldb are arbitrary binary sequences. Clients implement comparators to define ordering between keys. The default comparator for leveldb is something equivalent to strncmp. Chrome’s comparator for Indexed DB’s store is more complicated. If you try and use a leveldb instance with a different comparator than it was created with you’ll observe keys in … Read more