org.apache.commons.io

This package defines utility classes for working with streams, readers, writers and files. The most commonly used classes are described here:

IOUtils is the most frequently used class. It provides operations to read, write, copy and close streams.

FileUtils provides operations based around the JDK File class. These include reading, writing, copying, comparing and deleting.

FilenameUtils provides utilities based on filenames. This utility class manipulates filenames without using File objects. It aims to simplify the transition between Windows and Unix. Before using this class however, you should consider whether you should be using File objects.

FileSystemUtils allows access to the filing system in ways the JDK does not support. At present this allows you to get the free space on a drive.

EndianUtils swaps data between Big-Endian and Little-Endian formats.

Unless otherwise noted, these copy methods do not flush or close the streams.

This class operates with a FileFilter and maximum depth to limit the files and direcories visited. Commons IO supplies many common filter implementations in the filefilter package.

The following sections describe:

• 1.

Different computer architectures adopt different conventions for byte ordering.

This utility creates a background thread to handle file deletion. Each file to be deleted is registered with a handler object. When the handler object is garbage collected, the file is deleted.

In an environment with multiple class loaders (a servlet container, for example), you should consider stopping the background thread if it is no longer needed.

This utility creates a background thread to handle file deletion. Each file to be deleted is registered with a handler object. When the handler object is garbage collected, the file is deleted.

In an environment with multiple class loaders (a servlet container, for example), you should consider stopping the background thread if it is no longer needed.

When dealing with filenames you can hit problems when moving from a Windows based development machine to a Unix based production machine. This class aims to help avoid those problems.

NOTE: You may be able to avoid using this class entirely simply by using JDK java.io.File File objects and the two argument constructor java.io.File.File(java.io.Filejava.lang.String) File(File,String) .

Most methods on this class are designed to work the same on both Unix and Windows. Those that don't include 'System', 'Unix' or 'Windows' in their name.

Most methods recognise both separators (forward and back), and both sets of prefixes.

This class provides static utility methods for general file system functions not provided via the JDK java.io.File File class.

The current functions provided are:

• Get the free space on a drive

Facilities are provided in the following areas:

• writing to a file
• reading from a file
• make a directory including parent directories
• copying files and directories
• deleting files and directories
• converting to and from a URL
• listing files and directories by filter and extension
• comparing file content
• file last changed date
• calculating a checksum

Origin of code: Excalibur, Alexandria, Commons-Utils
author:
   Kevin A.

Different filing systems have different rules for case-sensitivity. Windows is case-insensitive, Unix is case-sensitive.

This class captures that difference, providing an enumeration to control how filename comparisons should be performed.

This class provides static utility methods for input/output operations.

• closeQuietly - these methods close a stream ignoring nulls and exceptions
• toXxx/read - these methods read data from a stream
• write - these methods write data to a stream
• copy - these methods copy all the data from one stream to another
• contentEquals - these methods compare the content of two streams

The byte-to-char methods and char-to-byte methods involve a conversion step. Two methods are provided in each case, one that uses the platform default encoding and the other which allows you to specify an encoding.

LineIterator holds a reference to an open Reader. When you have finished with the iterator you should close the reader to free internal resources.