Review

class CharArraySet {
  /** Add this char[] directly to the set.
   * If ignoreCase is true for this Set, the text array will be directly modified.
   * The user should never modify this text array after calling this method.
   */
  public boolean add(char[] text) {
    if (ignoreCase)
      for(int i=0;i<text.length;i++)
        text[i] = Character.toLowerCase(text[i]);
    int slot = getSlot(text, 0, text.length);
    if (entries[slot] != null) return false;
    entries[slot] = text;
    count++;

    if (count + (count>>2) > entries.length) {
      rehash();
    }

    return true;
  }
}

class CharArraySet.UnmodifiableCharArraySet {
    public boolean add(char[] text) {
      throw new UnsupportedOperationException();
    }

}