# Apache Commons Collections

> extended collections API for Java

**Wikidata**: [Q11190364](https://www.wikidata.org/wiki/Q11190364)  
**Source**: https://4ort.xyz/entity/apache-commons-collections

## Summary
Apache Commons Collections is a software library that provides an extended collections API for the Java programming language. Developed by the Apache Software Foundation, it is classified as free software distributed under the Apache License. The library serves as a utility to augment the standard Java collections framework.

## Key Facts
*   **Description:** An extended collections API for Java.
*   **Developer:** Apache Software Foundation.
*   **License:** Distributed under the Apache License.
*   **Software Class:** Instance of free software; functions as a software library.
*   **Programming Language:** Written in Java (an object-oriented programming language).
*   **Project ID:** `commons-collections` (Apache Project ID).
*   **Package Name:** `apache-commons-collections4` (openSUSE package).
*   **Repository Hosting:** Source code is maintained in both Git and Apache Subversion (SVN) repositories.

## FAQs
### Q: What is Apache Commons Collections used for?
A: It is a software library designed to provide an extended collections API for the Java programming language, supplementing the standard functionality available to developers.

### Q: Is Apache Commons Collections free to use?
A: Yes, it is classified as free software and is released under the Apache License, allowing users to run, study, change, and distribute it.

### Q: Where can issues regarding Apache Commons Collections be tracked?
A: Issues and bugs are tracked via the Apache JIRA instance at `http://issues.apache.org/jira/browse/COLLECTIONS`.

## Why It Matters
Apache Commons Collections plays a significant role in the Java ecosystem by filling gaps in the standard Java collections framework. As a project of the Apache Software Foundation, it offers a reliable, copyrighted, and open-source solution for developers requiring advanced data structure functionalities. Its classification as free software under the permissive Apache License ensures that it can be freely integrated into both open-source and commercial software without licensing fees.

The library matters because it extends the capabilities of Java—originally inceptioned in 1995—by providing specialized collection classes that are not found in the core Java Distribution. This reduces development time and boilerplate code for programmers. The project is maintained with transparent development practices, offering public access to its source code via Git and Subversion repositories, and is tracked on platforms like Open Hub and Repology, underscoring its active status and widespread adoption in the software development community.

## Notable For
*   Providing an extended API that goes beyond the native capabilities of the Java programming language.
*   Being a part of the Apache Software Foundation ecosystem, which ensures high standards of development and licensing.
*   Offering dual repository support via Git (`http://git-wip-us.apache.org/repos/asf/commons-collections.git`) and Apache Subversion.
*   Inclusion in package management systems like openSUSE (`apache-commons-collections4`) and Repology (`apache-commons-collections`).

## Body
### Development and Licensing
Apache Commons Collections is developed and maintained by the Apache Software Foundation. It is an instance of free software, distributed under the Apache License. The project has a Google Knowledge Graph ID of `/g/121j1_bs` and is tracked in the Free Software Directory as `Apache_Commons_Collections`.

### Technical Specifications
The library is written entirely in Java, the object-oriented programming language. It acts as a software library utility for Java developers. The project is identified by the Apache Project ID `commons-collections` and the Open Hub ID `Apache-Commons-Collections`.

### Distribution and Repositories
Users can download the software directly from the Apache website at `http://commons.apache.org/collections/download_collections.cgi`. The source code is accessible through two primary repositories:
*   **Git:** `http://git-wip-us.apache.org/repos/asf/commons-collections.git`
*   **Apache Subversion:** `http://svn.apache.org/repos/asf/commons/proper/collections`

The software has a specific package name in the openSUSE distribution: `apache-commons-collections4`.

### Project Resources
The official website for the project is hosted at `https://commons.apache.org/proper/commons-collections/` (with a legacy link at `http://commons.apache.org/collections/`). For development and maintenance, issues are tracked publicly at `http://issues.apache.org/jira/browse/COLLECTIONS`.

## References

1. [The Apache-Commons-Collections Open Source Project on Open Hub: Languages Page. Open Hub](https://www.openhub.net/p/Apache-Commons-Collections/analyses/latest/languages_summary)
2. [Source](https://projects.apache.org/json/projects/commons-collections.json)
3. [The Apache-Commons-Collections Open Source Project on Open Hub: Code Locations Page. Open Hub](https://www.openhub.net/p/Apache-Commons-Collections/enlistments)