Commons IO is a package of Java utility classes for java.io's hierarchy.  
Classes in this package are considered to be so standard and of such high 
reuse as to justify existence in java.io.

Commons IO contains utility classes, stream implementations, file filters, 
file comparators and endian transformation classes.

Compatibility with 2.0.1 and 1.4
--------------------------------

Binary compatible - Yes

Source compatible - Yes

Semantic compatible - Yes
  Check the bug fixes section for semantic bug fixes

Commons IO 2.1 requires a minimum of JDK 1.5
  (Commons IO 1.4 had a minimum of JDK 1.3) 


New features since 2.0.1
------------------------

o Use standard Maven directory layout  Issue: IO-285. Thanks to ggregory. 
o Add IOUtils API toString for URL and URI to get contents  Issue: IO-284. Thanks to ggregory. 
o Add API FileUtils.copyFile(File input, OutputStream output)  Issue: IO-282. Thanks to ggregory. 
o FileAlterationObserver has no getter for FileFilter  Issue: IO-262. 
o Add FileUtils.getFile API with varargs parameter  Issue: IO-261. 
o Add new APPEND parameter for writing string into files  Issue: IO-182. 
o Add new read method "toByteArray" to handle InputStream with known size.  Issue: IO-251. Thanks to Marco Albini. 

Fixed Bugs since 2.0.1
----------------------

o Dubious use of mkdirs() return code  Issue: IO-280. Thanks to sebb. 
o ReaderInputStream enters infinite loop when it encounters an unmappable character  Issue: IO-277. 
o FileUtils.moveFile() Javadoc should specify FileExistsException thrown  Issue: IO-264. 
o ClassLoaderObjectInputStream does not handle Proxy classes  Issue: IO-260. 
o Tailer returning partial lines when reaching EOF before EOL  Issue: IO-274. Thanks to Frank Grimes. 
o FileUtils.copyFile() throws IOException when copying large files to a shared directory (on Windows)  Issue: IO-266. Thanks to Igor Smereka. 
o FileSystemUtils.freeSpaceKb throws exception for Windows volumes with no visible files.
        Improve coverage by also looking for hidden files.  Issue: IO-263. Thanks to Gil Adam. 

Changes since 2.0.1
-------------------
o FileAlterationMonitor.stop(boolean allowIntervalToFinish)  Issue: IO-259.