pass objects from one class to another [duplicate]

There are several ways.

One of them is to use a constructor in its Main class:

public class Game {

    public static void main(String[] args) {
        Main main = new Main(new Team(), new Team());
    }
}

public class Main {

    Team teamUm;
    Team teamDois;

    public Main(Team teamUm, Team teamDois) {
        this.teamUm = teamUm;
        this.teamDois = teamDois;
    }
}

Another way is by set methods, invoked within Game :

public class Game {

    public static void main(String[] args) {
        Main main = new Main();
        main.setTeamUm(new Team());
        main.setTeamDois(new Team());
    }
}

public class Main {

    Team teamUm;
    Team teamDois;

    public void setTeamUm(Team teamUm) {
        this.teamUm = teamUm;
    }

    public void setTeamDois(Team teamDois) {
        this.teamDois = teamDois;
    }
}

I hope it helps!