Overview

The extended filesystem provides extensibility through the use of:

• An XFileAccessor interface that provides a common set of access methods that are required for all filesystems.

• An XFileExtensionAccessor abstract class that provides direct access to filesystem-specific features.

• The capability for automatic runtime selection of the file access mechanism.

• Support for multiple file namespaces through URL naming.

The API defines two means of access to network files and filesystems:

• An XFile class that supports naming of files with URLs such as the type described in Internet RFC 2224. Here users would specify URLs like "nfs://oaktree.edu/archie". Developers of other filesystems would register their own URL schemes and implement filesystem accessor classes to support a chosen filesystem type, such as "smb://www.microsoft.com/index.html". The XFile class also provides a default "native" URL scheme using java.io.* which has a file-naming syntax that varies according to the operating system that supports the Java Runtime Interface, such as Win95, UNIX, and VMS.

• Access to data through the XFileInputStream, XFileOutputStream, XRandomAccessFile, XFileReader and XFileWriter classes that are similar to current java.io.File classes.

The API supports three categories of applications:

• Web-based applications, specifically browsers that deal with URLs extensively.

• Traditional file-based applications that must extend their access to the network and still use the style of access provided by java.io.File classes.

• Mixed mode applications that use both remote and distributed filesystems.