Commons IO Overview – Apache Commons IO
Apache Commons IO ™
Last Published: 19 Apr 2026
Version: 2.22.0
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Apache Commons IO
Apache Commons IO is a library of utilities to assist with developing IO functionality.
The Commons IO packages include:
io
- This package defines utility classes for working with streams, readers, writers and files.
build
- This package provides classes to implement IO builders.
charset
- This package provides classes to work with code from
java.nio.charset
comparator
- This package provides various Comparator implementations for Files and Paths.
file
- This package provides extensions in the realm of java.nio.file.
file.attribute
- This package provides help using
java.nio.file.attribute
types.
file SPI
- This package provides extensions in the realm of
java.nio.file.spi
filefilter
- This package defines an interface (IOFileFilter) that combines both FileFilter and FilenameFilter.
function
- This package defines IO-only related functional interfaces for lambda expressions and method references.
input
- This package provides implementations of input classes, such as InputStream and Reader.
input.buffer
- This package provides implementations of buffered input classes, such as CircularBufferInputStream and PeekableInputStream.
monitor
- This package provides a component for monitoring file system events (directory and file create, update and delete events).
output
- This package provides implementations of output classes, such as OutputStream and Writer.
serialization
- This package provides a framework for controlling the deserialization of classes.
Releases
Latest Release (Java 8 and up)
Commons IO requires a minimum of Java 8 -
Download now
View the
Release Notes
and
Javadoc API documents
Previous Releases
See the
download archive
and
Javadoc archive
The Java platform requirements are:
Version 2.7 and up requires Java 8 or above.
Version 2.6 requires Java 7 or above.
Version 2.3 through 2.5 requires Java 6 or above.
Version 2.2 requires Java 5 or above.
Support
The
commons mailing lists
act as the main support forum.
The user list is suitable for most library usage queries.
The dev list is intended for the development discussion.
Please remember that the lists are shared between all commons components,
so prefix your email by [io].
Issues may be reported via
ASF JIRA
Please read the instructions carefully to submit a useful bug report or enhancement request.
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The Apache Software Foundation
Apache Commons, Apache Commons IO, Apache, the Apache logo, and the Apache Commons project logos are trademarks of The Apache Software Foundation.
All other marks mentioned may be trademarks or registered trademarks of their respective owners.