How can I see what file's are in a directory

Question

I'm want to make a program for brosing the harddisk and copying and editing file's.
I already can copy them but:
How can I see what file's are in a directory and how can I see
what subdirectory's are in a directory so I can show them to the user?
I dont't know if it does matter if If I'm on a windows or linux platform, when it does please tell me for the windows?

Answer 1

I believe this works for a directory of reasonable size.
import java.io.File;
final public class FileSearch {
    public File current;
    public String path;
    public File[] files;
    public FileSearch(File dir){
       try {
          current = dir;
          files = dir.listFiles();
       } catch (Exception e) {
          e.printStackTrace();
    public void currentSearch() {
       for (int i=0; i<files.length; i++) {
          if (files.isFile()) {
System.out.println(files[i].toString());
public void searchFiles(){
for (int i=0; i<files.length; i++) {
if (files[i].isDirectory()) {
System.out.println();
System.out.print("directory: ");
System.out.println(files[i].toString());
try {
FileSearch sub = new FileSearch(files[i]);
sub.currentSearch();
sub.searchFiles();
sub= null;
} catch (Exception e) {
e.printStackTrace();
public static void main(String[] args) {
try {
FileSearch search = new FileSearch(new File("."));
search.currentSearch();
search.searchFiles();
} catch (Exception e) {
e.printStackTrace();