How to retrieve a list of directories QUICKLY in Java?

Question

Suppose a very simple program that lists out all the subdirectories of a given directory. Sound simple enough? Except the only way to list all subdirectories in Java is to u

Answer 1

I don't know if the overhead of shelling out to cmd.exe would eat it up, but one possibility would be something like this:

...
Runtime r = Runtime.getRuntime();
Process p = r.exec("cmd.exe /k dir /s/b/ad C:\\folder");
BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
for (;;) {
    String d = br.readLine();
    if (d == null)
        break;
    System.out.println(d);
}
...

• /s means search subdirectories
• /ad means only return directories
• /b means return the full pathname from the root