Write a function to detect if two strings are anagrams (for example, SAVE and VASE)

public static boolean isAcronym(String s1, String s2) {

    if (s1.length() != s2.length()) return false;

    HashMap<Character, Integer> charCounts = new HashMap<>();

    // Calculate chracter counts

    for (int i = 0; i < s1.length(); i++) {
      if (charCounts.containsKey(s1.charAt(i))) {
           charCounts.put(s1.charAt(i), charCounts.get(s1.charAt(i)) + 1);
      } else {
           charCounts.put(s1.charAt(i), 1);
      }
    }

    // Compare counts with characters in s2

    for (int i = 0; i < s2.length(); i++) {
        if (charCounts.containsKey(s2.charAt(i))) {
           charCounts.put(s2.charAt(i), charCounts.get(s2.charAt(i)) - 1);
        } else {
           return false;
        }
    }

    // Check all letters matched
    for (int count : charCounts.values()) {
        if (count != 0) return false;
    }

    return true;
}