Java Open Source Projects Directory

The Google Collections Library is a suite of new collections and collection-related goodness for Java 5.0. This library is a natural extension of the Java Collections Framework. The major new types are:

 * BiMap. A Map that guarantees unique values, and supports an inverse view.
 * Multiset. A Collection that may contain duplicate values like a List, yet has order-independent equality like a Set. Often used to represent a histogram.
 * Multimap. Similar to Map, but may contain duplicate keys. Has subtypes SetMultimap and ListMultimap providing more specific behavior.

• Category: Collections
• License:  Apache Software License
• HomePage: http://code.google.com/p/google-collections/

tclib - Type-Specific Collections Library.

• Category: Collections
• License:  Other
• HomePage: http://www.sosnoski.com/opensrc/tclib/index.html

Primitive Collections for Java (PCJ) is a set of collection classes for primitive data types in Java. The goal is to provide an efficient alternative to the Java Collections Framework (JCF) when using primitive data types, such as int, boolean, or double.

• Category: Collections
• License:  GNU Library or Lesser General Public License (LGPL)
• HomePage: http://pcj.sourceforge.net/

Hist4j is a histogram library for Java that accepts large datasets with any distribution or range and has a very small memory footprint, needs no pre- or post-processing, and provides several statistical functions about the data seen so far.

• Category: Collections
• License:  Apache Software License
• HomePage: http://opensource.flaptor.com/hist4j/index.html

Trove provides a "free", fast, lightweight implementations of the java.util Collections API. These implementations are designed to be pluggable replacements for their JDK equivalents.

• Category: Collections
• License:  GNU Library or Lesser General Public License (LGPL)
• HomePage: http://trove4j.sourceforge.net/

Mango is a Java library consisting of a number of iterators, algorithms and functions, loosely inspired by the C++ Standard Template Library.

• Category: Collections
• License:  GNU Library or Lesser General Public License (LGPL)
• HomePage: http://www.jezuk.co.uk/cgi-bin/view/mango

fastutil extends the Java Collections Framework by providing type-specific maps, sets, lists and queues with a small memory footprint and fast access and insertion.

• Category: Collections
• License:  GNU Library or Lesser General Public License (LGPL)
• HomePage: http://fastutil.dsi.unimi.it/

Apache Jakarta Commons Primitives provides a collection of types and utilities optimized for working with Java primitives (boolean, byte, char, double, float, int, long, short). Generally, the Commons-Primitives classes are smaller, faster and easier to work with than their purely Object based alternatives.

• Category: Collections
• License:  Apache Software License
• HomePage: http://jakarta.apache.org/commons/primitives/