Hi everyone,

I just want to use Collections.sort or Arrays.sort to sort a list of points (class Point) by x first and then by y.

I have a class Ponto that implements Comparable like this:

public int compareTo(Ponto obj) {
        Ponto tmp = obj;
        if (this.x < tmp.x) {
            return -1;
        } else if (this.x > tmp.x) {
            return 1;
        }
        return 0;
    }

but now I want to sort by y too after x.

How can I do that by modifying the above code? Or is that a better and "clean" way to do this? I also use to pass this code to C++, in which I've created a structure called Point with a equivalent comparable method.