java.io.File.listFiles() is unable to read nfs-mounted directory from MacOS X.
1. Testcase
-----------
Here is a short testprogram:
% more Main.java
import java.io.File;
public class Main {
        public static void main(String[] args){
                if(args.length != 1){
                        System.out.println("USAGE: ");
                        System.out.println(" java Main <directory_on_nfs_mount>");
                        System.out.println();
                        System.exit(1);
                }
                String filename = args[0];
                File file = new File(filename);
                if(! file.exists() ){
                        System.out.println("file "+filename+" does not exist.");
                }
                else if ( file.isFile() ){
                        System.out.println("f "+filename);
                }
                else if ( file.isDirectory() ){
                        System.out.println("listing contents of directory "+filename);
                        File[] subfiles = file.listFiles();
                        for( int i=0 ; i<subfiles.length ; i++ ){
                                System.out.print( subfiles[i].isFile() ? "f " : "d " );
                                System.out.println( subfiles[i].getName() );
                        }
                        System.out.println();
                        System.out.println( subfiles.length + " files total");
                }
        }
}
2. nfs-directory
----------------
I used an nfs directory mounted via automounter shared from MacOS 10.4.5 (Darwin 8.5.0):
3. Compile
----------
% /j2sdk1.4.2_11/bin/java -version
java version "1.4.2_11"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_11-b02)
Java HotSpot(TM) Client VM (build 1.4.2_11-b02, mixed mode)
% /j2sdk1.4.2_11/bin/javac Main.java
% 
4. Run
------
 I blanked the ip_adress using "<ip_addr>" in the output below.
% /j2sdk1.4.2_11/bin/java -version
java version "1.4.2_11"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.2_11-b02)
Java HotSpot(TM) Client VM (build 1.4.2_11-b02, mixed mode)
% /j2sdk1.4.2_11/bin/java Main /net/<ip_addr>
listing contents of directory /net/<ip_addr>
d Users
1 files total
% 
 That's fine...
% /j2sdk1.4.2_11/bin/java Main /net/<ip_addr>/Users
listing contents of directory /net/<ip_addr>/Users
d thomas
1 files total
% 
 That's fine...
% /j2sdk1.4.2_11/bin/java Main /net/<ip_addr>/Users/thomas
listing contents of directory /net/<ip_addr>/Users/thomas
d Public
1 files total
% 
 That's fine...
% /j2sdk1.4.2_11/bin/java Main /net/<ip_addr>/Users/thomas/Public
listing contents of directory /net/<ip_addr>/Users/thomas/Public
0 files total
% 
 That's wrong ....
% ls -l /net/<ip_addr>/Users/thomas/Public
total 16
drwx-wx-wx   3 thomas  990          102 Nov 30 13:18 Drop Box
-rwxrwxrwx   1 thomas  990           18 Mar  8 13:35 Hallo_Thomas.txt
%
% df -k /net/<ip_addr>/
Filesystem            kbytes    used   avail capacity  Mounted on
-hosts                     0       0       0     0%    /net
% df -k /net/<ip_addr>/Users/
Filesystem            kbytes    used   avail capacity  Mounted on
-hosts                     0       0       0     0%    /net/<ip_addr>/Users
% df -k /net/<ip_addr>/Users/thomas/
Filesystem            kbytes    used   avail capacity  Mounted on
-hosts                     0       0       0     0%    /net/<ip_addr>/Users/thomas
% df -k /net/<ip_addr>/Users/thomas/Public
Filesystem            kbytes    used   avail capacity  Mounted on
<ip_addr>:/Users/thomas/Public
                     58474008 31462436 26755572    55%    /net/<ip_addr>/Users/thomas/Public
%