URL Names and Native Names

Filenames are assumed to be absolute URLs or relative URLs as determined by a context. If a filename string begins with a valid URL scheme name followed by a colon, then the name is associated with the filesystem type indicated by the URL scheme name. For instance, a filename string of the form "nfs://hostname/path" is associated with the filesystem that has the scheme name of "nfs". If the filename has no colon-separated prefix, or the scheme is not recognized then the name is assumed to belong to the default "native" scheme, that is, a URL prefix of "native:" is assumed and the name is handled by java.io.*. The two-argument constructor for XFile takes an XFile object and a filename:

 XFile(XFile dir, String filename).

The filename argument is interpreted according to the context set by the dir argument. The dir argument is used as a base URL and the name is evaluated as a relative URL. If the filename is an absolute URL, then the diris ignored. If the filename is a relative URL, then it is combined with the base URL to form the name of the new XFile object. The rules that describe the evaluation of relative URLs are described in RFC 1808.