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Commons IO

Commons IO is a library of utilities to assist with developing IO functionality.

There are six main areas included:

  • Utility classes - with static methods to perform common tasks
  • Input - useful Input Stream and Reader implementations
  • Output - useful Output Stream and Writer implementations
  • Filters - various implementations of file filters
  • Comparators - various implementations of java.util.Comparator for files
  • File Monitor - a component for monitoring file system events


Commons IO 2.4 (requires JDK 1.6+)

Commons IO 2.4 is the latest version and requires a minimum of JDK 1.6 - Download now!

View the Release Notes and JavaDoc API documents

Commons IO 2.2 (requires JDK 1.5+)

Commons IO 2.2 requires a minimum of JDK 1.5 - Download now!

View the Release Notes and JavaDoc API documents

Older Releases

For previous releases, see the Apache Archive.


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.