Sort anagram lists

Write a method to sort an array of strings so that all the anagrams are next to each other.

The basic idea is to write a function and rearrange the string to its lexicographic order, and use String comparator to compare two strings. Some concepts about String comparator from Java doc: 

Compares two strings lexicographically. The comparison is based on the Unicode value of each character in the strings. The character sequence represented by this String object is compared lexicographically to the character sequence represented by the argument string. 

The result is a negative integer if this String object lexicographically precedes the argument string. The result is a positive integer if this String object lexicographically follows the argument string. The result is zero if the strings are equal;compareTo returns 0 exactly when the equals(Object) method would return true.

If two strings are different, then either they have different characters at some index that is a valid index for both strings, or their lengths are different, or both. If they have different characters at one or more index positions, let k be the smallest such index; then the string whose character at position k has the smaller value, as determined by using the < operator, lexicographically precedes the other string.  

private static class AnagramComparator implements Comparator {
  public static String sortChars(String s) {
   char[] content = s.toCharArray();
   Arrays.sort(content);
   return new String(content);
  }
  public int compare(String s1, String s2) {
   return sortChars(s1).compareTo(sortChars(s2));
  }
 }
 public static void sortStrings(List list) {
  Collections.sort(list, new AnagramComparator());
 }