Unique Chars (has repeated chars)

public class UniqueLetters {
    public static void main (String args[]) {
        System.out.println(hasUnique("abc"));
        System.out.println(hasUnique("abca"));
        System.out.println(hasUnique("a"));
    }

    public static boolean hasUnique (String word) {

        if (word.length() > 1)
            for (int i=0; i<word.length()-1; i++) {
                for (int j=i+1; j<word.length(); j++)
                    if (word.charAt(i) == word.charAt(j))
                        return false;
            }

        return true;
    }

}