Commons Collections is a program package for Windows which offers a comprehensive set of classes and instruments that go beyond what is available in the standard Java collections framework. It is a part of the large Apache Commons project that aims to provide reusable, open source Java components.

General notes

The software distribution introduces new collection types, such as bags, multimaps, and extended list implementations. These classes address specific use cases that may not be fully covered by basic Java compilations.

The library delivers utility classes for enhancing the efficiency of working with collections. It encompasses features for creating composites, identifying variances, and altering structures. If you would like to integrate mathematical functions into Java projects, you may try a library called Apache Commons Math.

Transforming decorators

A standout aspect of this package is the incorporation of the decorator pattern. It empowers you to improve or modify the behavior of current collection classes without changing their fundamental structure. This approach fosters adaptability and reliability within the codebase.

Since this is an open source project, it is important to verify that the library undergoes regular maintenance and remains compatible with the most recent language versions. This program requires Java 8 or later editions.

Features

free to download and use;
compatible with modern Windows versions;
allows you to deploy additional Java components;
you can collect multiple copies of each object;
there is support for handling null values.