First Unique Character in a String

public int findUniqueChar(String s) {
    int uniqueCharIndex = -1;

    for (int i = 0; i < s.length(); i++) {
        boolean unique = true;
        char currentChar = s.charAt(i);

        for (int j = 0; j < s.length(); j++) {
            if (currentChar == s.charAt(j) && i != j) {
                unique = false;
                break;
            }
        }

        if (unique = true) {
            uniqueCharIndex = 1;
            break
        }
    }
    
    return uniqueCharIndex;
}