Name: krT82822 Date: 10/28/99


all versions to date

The File.list() method returns String[]. File.list(FilenameFilter) also returns
String[]. The problem is that when a directory has tens of thousands of files
in it, the use of File.list() can cause a huge VM size explosion. In most
applications processing files, it is not necessary to see all of the files at
once. One file at a time is fine. The Posix readdir functionality in
particular is handy in these cases so that one can process all the entries
in a directory, one at a time.

I'd like to suggest that a new method be provided in File that will facilitate
the convienent processing of large directories. Here's my suggestion.

public void scan( FileEntryAction act ) throws IOException;

public interface FileEntryAction {
    pubic void processFile( File dir, String name );
}

This would allow the activities to be implemented in another class if needed
and eliminate the need for such a huge array for large directories.

The reason I am purposing this instead of the alteration of the behavior of
File.list( FilenameFilter ) to filter as files are found, is that I think the
above purposal is more general solution and avoids the array creation
altogether.
(Review ID: 97165)
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