system( 'dir /b /s > files.tmp' );

open( IN, 'files.tmp' );
my @files = grep( /\.java$/, <IN> );
close IN;

chomp( @files );

system( 'del files.tmp' );

print "Processing files.\n";
my $file;
foreach $file (@files)
{
   ...
}

##</code><code>##

use File::Find;

find ({
    'wanted'            =>  \&processfile,
    'follow'            =>  0
}, '/');

sub processfile {
    my ($dev, $ino, $mode, $nlink, $uid, $gid);
    return unless (($dev, $ino, $mode, $nlink, $uid, $gid) = lstat($_));
    return unless -f _ && -r _ && /^.*\.java\z/si;

    ...
};