public class StringEnum { public static void main(String[] args) { System.out.println(Arrays.toString(permutation("abc"))); } private static String[] permutation(String orginal) { ArrayList list = new ArrayList(); if (orginal.length() == 1) { return new String[] { orginal }; } else { for (int i = 0; i < orginal.length(); i++) { String s = orginal.charAt(i) + ""; String result = ""; String resultA = result + s; String leftS = orginal.substring(0, i) + orginal.substring(i + 1, orginal.length()); for (String element : permutation(leftS)) { result = resultA + element; list.add(result); } } return (String[]) list.toArray(new String[list.size()]); } } }