Top Collections Libraries for Java

Guava: Google Core Libraries for Java · Guava is a suite of core and expanded libraries that include utility classes, Google's collections, I/O classes, and much more.

Disruptor Framework · Disruptor - Concurrent Programming Framework

mapdb · MapDB provides concurrent Maps, Sets and Queues backed by disk storage or off-heap memory. It is a fast, scalable and easy to use embedded Java database.

Java Concurrency Tools Core Library · Java Concurrency Tools Core Library

agrona · High performance primitives and utility library.

fastutil · 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; it provides also big (64-bit) arrays, sets and lists, sorting algorithms, fast, practical I/O classes for binary and text files, and facilities for memory mapping large files. Note that if you have both this jar and fastutil-core.jar in your dependencies, fastutil-core.jar should be excluded.

Koloboke Collections API · Carefully designed and efficient extension of the Java Collections Framework with primitive specializations and more, built for Java 8 (API)

High Performance Primitive Collections · High Performance Primitive Collections: data structures (maps, sets, lists, stacks, queues) generated for combinations of object and primitive types to conserve JVM memory and speed up execution.

JavaEWAH · The bit array data structure is implemented in Java as the BitSet class. Unfortunately, this fails to scale without compression. JavaEWAH is a word-aligned compressed variant of the Java bitset class. It uses a 64-bit run-length encoding (RLE) compression scheme. The goal of word-aligned compression is not to achieve the best compression, but rather to improve query processing time. Hence, we try to save CPU cycles, maybe at the expense of storage. However, the EWAH scheme we implemented is always more efficient storage-wise than an uncompressed bitmap (implemented in Java as the BitSet class). Unlike some alternatives, javaewah does not rely on a patented scheme.

Apache Commons Collections · Types that extend and augment the Java Collections Framework.

Apache Commons Collections · The Apache Commons Collections package contains types that extend and augment the Java Collections Framework.