Java String Permutation

Permute.java

public class Permute {
    public static void main(String args[]) {
        permute(args[0]);
    }

    public static void permute(String list) {
        boolean[] used = new boolean[list.length()];
        char[] in = list.toCharArray();
        StringBuffer out = new StringBuffer();
        int level = 0;
        doPermute(used, in, out, level);
    }

    public static void doPermute(boolean[] used, char[] in, StringBuffer out, int level) {
        if (level == in.length) {
            System.out.println(out.toString());
            return;
        }

        for (int i=0; i < in.length; i++) {
            if (used[i]) {
                continue;
            }

            System.out.println(out.length());
            out.append(in[i]);

            used[i] = true;
            doPermute(used, in, out, level + 1);
            used[i] = false;

            out.setLength(out.length() - 1);
            System.out.println(out);
        }
    }
}