Why I am receiving this result? JAVA

Question

I am learning to use Comparators and I am getting a very strange result in the console when executing my program:

I define an Object called Zapato whose attribute's values are passed through the arguments after asked for them to the user:

public class Zapato {

    int talla;
    String color;
    int precio;

    public Zapato (int talla,String color,int precio){
        this.talla = talla;
        this.color = color;
        this.precio = precio;
    }

}

Then I created some comparators based on the color or the price for example.

public class OrdenarPorColor implements Comparator<Zapato>{

    @Override
    public int compare(Zapato z1, Zapato z2) {

        return z1.color.compareTo(z2.color);
    }
}

In Main I ask for the values,create 3 objects and I save them on an ArrayList.Then the user has to select the comparison mode and I invoke the class of the comparison mode selected and after sorting the list,I print it the 3 objects sorted:

//Before this there is code repeated where I ask the values for the other 2 objects
 System.out.println("Introduzca la talla,el color y la talla de los zapatos: ");
        System.out.println("Talla: ");
        talla = Integer.parseInt(sc.nextLine());
        System.out.println("Color: ");
        color = sc.nextLine();
        System.out.println("Precio: ");
        precio = Integer.parseInt(sc.nextLine());

        listaZapatos.add(new Zapato(talla,color,precio));
        System.out.println("Zapato introducido es: " + listaZapatos.get(2));


        System.out.println("Escriba la opcion para comparar:");
        System.out.println("1-Por talla\n2-Por color\3-Por precio");
        System.out.println("Opcion: ");

        int opcion = sc.nextInt();

        switch (opcion){

            case 1:
                Collections.sort(listaZapatos,new OrdenarPorTalla());
                System.out.println(listaZapatos);
                break;
            case 2:
                Collections.sort(listaZapatos,new OrdenarPorColor());
                System.out.println(listaZapatos);
                break;
            case 3:
                Collections.sort(listaZapatos,new OrdenarPorPrecio());
                System.out.println(listaZapatos);
                break;
        }

        return;

But when the program prints them System.out.println(listaZapatos) ,it should appear something like

45 Rosa 32,56 Azul 21,34 Verde 46

but instead I receive this on the console:

[Main.Zapato@2ff4acd0, Main.Zapato@279f2327, Main.Zapato@54bedef2]

Also it appears when I print the object created with the introduced values every time I ask for them in System.out.println("Zapato introducido es: " + listaZapatos.get(2)) so I receive things like this:

Main.Zapato@2ff4acd0

Answer 1

You need to override the toString implementation in your Zapato class. When printing a Collection, internally the method will call toString() on each object in that collection. The default toString implementation gives you the data you want.

Something like this will help:

@Override
public String toString()
{
    return color + ":" + talla;
}

In your Zapato class