Java IO.pdf - Nguyen Dang Binh

Java I/O
• Do not parse pathnames to find directories. Use the methods of the java.io.File
class instead.
• Do not use renameTo() for anything except renaming a file. In particular, do not use it
to move a file.
• Try to avoid moving and copying files from within Java programs if at all possible.
• Do not use . to refer to the current directory. Use System.getProperty
("user.dir") instead.
• Do not use .. to refer to the parent directory. Use getParent() instead.
• Do not assume the current working directory is the one where your .class files live. It
almost certainly won't be that directory on the Mac, and it may not be on other
platforms, including Windows and Unix.
• Place any data files your program requires in JAR archives rather than directly in the
filesystem, then load them as resources from the class path.
• When in doubt, it never hurts to convert filenames to canonical form.
• Do not assume anything about filesystem conventions. Some platform somewhere will
surprise you. (Have you tested your program on BeOS yet?)
• Test your code on as many different filesystems as you can get your hands on.
Despite all the problems I've pointed out, it is mostly possible to write robust file access code
that works across all platforms where Java runs. But doing so requires understanding, effort,
and thought. You cannot simply write for Windows or Unix and hope things will work out for
the best on other platforms. You must plan to handle a wide range of filesystems and filename
conventions.
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