Sux4J is an effort to bring succinct data structures to Java.
JavaLGPL-2.1
Welcome to Sux4J!
Sux4J is an effort to bring succinct data
structures to Java. Presently it provides a number of related
implementations covering ranking/selection over bit arrays, compressed
lists and [[monotone] minimal perfect hash] functions.
Building
You need Ant and Ivy.
Then, run ant ivy-setupjars jar.