How to compare objects by multiple fields

Question

Assume you have some objects which have several fields they can be compared by:

public class Person {

    private String firstName;
    private String lastN         


        

Answer 1

Usually I override my compareTo() method like this whenever I have to do multilevel sorting.

public int compareTo(Song o) {
    // TODO Auto-generated method stub
    int comp1 = 10000000*(movie.compareTo(o.movie))+1000*(artist.compareTo(o.artist))+songLength;
    int comp2 = 10000000*(o.movie.compareTo(movie))+1000*(o.artist.compareTo(artist))+o.songLength;
    return comp1-comp2;
} 

Here first preference is given to movie name then to artist and lastly to songLength. You just have to make sure that those multipliers are distant enough to not cross each other's boundaries.