Compare Integer, arrays of class instances

Question

Ok so I'm kind of in the loss here but here goes. So I need to sort the array medalList when they get printed out. First I need to sort by gold medals which are added to the index [0], second after silvers in index [1], third after bronze in index [2] and last if a team is tied they get sorted by team name. Do I need to call a sorting method in another class, keep track of one and sort through and compare to the rest of the teams and if they're the best print them out first?

How do I compare Integers in an array of one classes to another?

When a user enters a certain command a list of teams with their results will get printed out.

As of now it looks like this:

1st 2nd 3rd  Team Name
0   0     0      North Korea
3   1     1      America
5   0     2      France
2   1     3      Germany

I want it to say:

1st 2nd 3rd  Team Name
5   0     2  France
3   1     1  America
2   1     3  Germany
0   0     0  North Korea

import java.util.ArrayList;
import java.util.Arrays;

public class Team {
    private String teamName;
    private ArrayList<Participant> participantList = new ArrayList<Participant>();
    private int[] medalList = new int[3];

    public Team(String teamName) {
        this.teamName = teamName;
    }

    public String getTeamName() {
        return teamName;
    }

    public void addParticipant(Participant participant) {
        participantList.add(participant);
    }

    public void removeFromTeam(int participantNr){
        for(int i = 0; i < participantList.size(); i++){
            if(participantList.get(i).getParticipantNr() == participantNr){
                participantList.remove(i);
            }
        }
    }

    public void printOutParticipant() {
        for(int i = 0; i < participantList.size(); i++){
            System.out.println(participantList.get(i).getName() + " " + participantList.get(i).getLastName());
        }
    }

    public boolean isEmpty() {
        boolean empty = false;
        if (participantList.size() == 0) {
            empty = true;
            return empty;
        }
        return empty;
    }

    public void emptyMedalList(){
        Arrays.fill(medalList, 0);
    }

    public void recieveMedals(int medal) {
        if(medal == 1){
            int gold = 0;
            gold = medalList[0];
            medalList[0] = ++gold;
        } else if (medal == 2){
            int silver = 0;
            silver = medalList[1];
            medalList[1] = ++silver;
        } else if (medal == 3){
            int bronze = 0;
            bronze = medalList[2];
            medalList[2] = ++bronze;
        }
    }

    public void printMedals(){
        System.out.println(medalList[0] + "   " + medalList[1] + "   " + medalList[2] + "   " + teamName);
    }

   public int compareTo(Team team) {
    int goldDif = Integer.compare(team.medalList[0], this.medalList[0]);
    if (goldDif != 0)
            return goldDif;
    int silverDif = Integer.compare(team.medalList[1], this.medalList[1]);
    if (silverDif != 0)
        return silverDif;
    int bronzeDif = Integer.compare(team.medalList[2], this.medalList[2]);
    if (bronzeDif != 0)
        return bronzeDif;
    return this.getTeamName().compareTo(team.getTeamName());
}

    public String toString() {
        return teamName;
    }

}

Answer 1

Make your Team class comparable

public class Team implements Comparable<Team> {

and add a comparison method

@Override
public int compareTo(final Team other) {
    for (int i = 0; i < 3; i++) {
        final int compareMedals = Integer.compare(medalList[i], other.medalList[i])
        if (compareMedals != 0) {
            return compareMedals;
        }
    }
    return teamName.compareTo(other.teamName);
}

This will check gold medals first, then silver medals if the amount of gold medals is equal and so on and use the team name comparison as a last resort. You can then sort a collection of Teams with

final List<Team> teams = new ArrayList<>();
...
Collections.sort(teams);

EDIT:

Or if you like it in Java 8 style you could also write your comparison method like

@Override
public int compareTo(final Team other) {
    return Stream.of(0, 1, 2)
                .map(i -> Integer.compare(medalList[i], other.medalList[i]))
                .filter(i -> i != 0)
                .findFirst()
                .orElse(teamName.compareTo(other.teamName));
}