The Apache Commons is a project of the Apache Software Foundation, formerly under the Jakarta Project. The purpose of the Commons is to provide reusable, open source Java software. The Commons is composed of three parts: proper, sandbox, and dormant.
Commons Proper The Commons Proper is dedicated to creating and maintaining reusable Java components. The Commons Proper is a place for collaboration and sharing, where developers from throughout the Apache community can work together on projects to be shared by Apache projects and Apache users. Commons developers will make an effort to ensure that their components have minimal dependencies on other software libraries, so that these components can be deployed easily. In addition, Commons components will keep their interfaces as stable as possible, so that Apache users, as well as other Apache projects, can implement these components without having to worry about changes in the future.The Apache Commons root page
Components Description Latest version Released BCEL Byte Code Engineering Library - analyze, create, and manipulate Java class files 6.13.0 2026-09-06BeanUtils Easy-to-use wrappers around the Java reflection and introspection APIs 1.11.0 2025-05-25 BSF Bean Scripting Framework - interface to scripting languages, including JSR-223 3.1 2011-08-17 Chain Chain of Responsibility pattern implementation 1.2 2008-06-01 CLI Command Line arguments parser 1.11.0 2025-11-08 Codec General encoding/decoding algorithms (for example phonetic, base64, URL) 1.22.1 2026-07-27 Collections Extends or augments the Java Collections Framework 4.6.0 2026-08-06 Compress Defines an API for working with TAR, ZIP and BZIP2 files 1.28.0 2025-07-26 Configuration Reading of configuration/preferences files in various formats 2.15.1 2026-05-21 Crypto Cryptographic library optimized with AES-NI wrapping OpenSSL or JCE algorithm implementations 1.2.0 2023-01-14 CSV Component for reading and writing comma separated value files 1.14.0 2025-03-15 Daemon Generic Daemon (unix) or Service (Windows) wrapper for Java code 1.6.1 2026-06-03 DBCP Database connection pooling services 2.14.0 2025-12-11 DbUtils JDBC helper library 1.8.1 2023-09-09 Digester XML-to-Java-object mapping utility 3.2 2011-12-13 Email Library for sending e-mails 1.5 2017-08-01 Exec API for dealing with external process execution and environment management 1.6.0 2025-11-25 FileUpload File upload capability for servlets and web applications 1.6.0 2025-06-05 Functor Supports functional programming using functors, objects representing functions 1.0 RC1 2011-10-20 Geometry General-purpose library for geometric processing 1.0 2021-08-21 Imaging Pure-Java image library 1.0-alpha6 2025-04-27 IO Collection of I/O utilities 2.22.0 2026-04-19 JCI Java Compiler Interface 1.1 2013-10-14 JCS Java Caching System 3.2.1 2024-05-27 Jelly XML based scripting and processing engine 1.0.1 2017-09-25 JEXL Expression language which extends the Expression Language of the JSTL 3.6.3 2026-06-20 JXPath Utilities for manipulating Java Beans using the XPath syntax 1.4.0 2025-04-12 Lang Provides extra functionality for classes in java.lang 3.21.0 2026-09-25 Logging Wrapper around a variety of logging API implementations 1.4.0 2026-06-11 Math Lightweight, self-contained mathematics and statistics components 4.0-beta1 2022-12-20 Net Collection of network utilities and protocol implementations 3.13.0 2026-03-15 Numbers Number types (complex, quaternion, fraction) and utilities (arrays, combinatorics) 1.3 2026-04-20 Pool Generic object pooling component 2.13.1 2025-12-30 Proxy Library for creating dynamic proxies 2.0-RC1 2014-04-07 RDF Common implementation of RDF 1.1 that could be implemented by systems on the JVM 0.5.0 2017-12-08 RNG Implementions of pseudo-random numbers generators 1.6 2024-07-15 SCXML Implementation of the State Chart XML specification aimed at creating and maintaining a Java SCXML engine 2.0-M1 2014-04-03 Statistics Utilities for statistical applications 1.3 2026-05-01 Text Library focused on algorithms working on strings 1.15.0 2025-12-04 Validator Framework to define validators and validation rules in an XML file 1.11.0 2026-07-28 VFS Virtual File System component for treating files, FTP, SMB, ZIP and such like as a single logical file system 2.10.0 2025-02-01 Weaver Provides an easy way to enhance (weave) compiled bytecode 2.0 2018-09-07
Commons Sandbox The Commons Sandbox provides a workspace where Commons contributors collaborate and experiment on projects not included in the Commons Proper. Commons members champion projects in the Sandbox for promotion to the Commons Proper, and groups of developers work to enhance Sandbox projects until they meet the standards for promotion.
Components Description BeanUtils2 Redesign of Commons BeanUtils ClassScan Find Class interfaces, methods, fields, and annotations without loading CLI2 Redesign of Commons CLI Convert Aims to provide a single library dedicated to the task of converting an object of one type to another Finder Java library inspired by the UNIX find command Flatfile Java library for working with flat data structures Graph General purpose Graph APIs and algorithms I18n Adds the feature of localized message bundles that consist of one or many localized texts that belong together Id Component for generating identifiersInjectImplementation of JSR 330, a standards compliant dependency injection framework Javaflow Continuation implementation to capture the state of the application JNet Allows using dynamically registered URL stream handlers through the java.net APIMonitoringAims to provide a simple but extensible monitoring solution for Java applications Nabla Provides automatic differentiation classes that can generate derivative of any function implemented in the Java language OpenPGP Interface to signing and verifying data using OpenPGP Performance Small framework for microbenchmark clients, with implementations for Commons DBCP and Pool Pipeline Provides a set of pipeline utilities designed around work queues that run in parallel to sequentially process data objects
Commons Dormant The Commons Dormant is a collection of components that have been declared inactive due to little recent development activity. These components may be used, but must be built yourself. It is best to assume that these components will not be released in the near future.
Components Description Attributes Runtime API to metadata attributes such as doclet tags Betwixt Services for mapping JavaBeans to XML documents and vice versa Cache Provides object caching services Clazz Focuses on introspection and class manipulation Contract Component for making features that come along with contract based programming available Convert Aims to provide a single library dedicated to the task of converting an object of one type to anotherDiscoveryTools for locating resources by mapping service/reference names to resource namesELInterpreter for the Expression Language defined by the JSP 2.0 specification Events Provides additional classes for firing and handling events. It focuses on the Java Collections Framework, providing decorators to other collections that fire events. Feedparser RSS and Atom parser designed to support all major versions of RSS and Atom, as well as easy ad hoc extension and RSS 1.0 modules capability JJar Jakarta JAR Archive Repository Latka HTTP functional testing suite for automated QA, acceptance and regression testingLauncherCross platform Java application launcher Mapper Thin abstraction layer around a project's chosen data mapping technology (a.k.a. DAO pattern) Messenger Easy to use and lightweight framework for working with JMS in the web tierModelerMechanisms to create Model MBeans compatible with JMX specification OGNL Object-Graph Navigation LanguagePrimitivesSmaller, faster and easier to work with types supporting Java primitive types Resources Provides a lightweight framework for defining and looking up internationalized message strings keyed by a java.util.Locale and a message key Scaffold Toolkit for building web applications ThreadPool Simple component for asynchronously dispatching work to another thread in a pool for simple multithreaded programming Transaction Implementations for multi-level locks, transactional collections and transactional file access Workflow Provides a framework for building workflow management systems XMLIO Simple and fast importer for XML configuration or import files
See also
Google Guava
References
External links Apache Commons