Car.java

public class Car implements Comparable<Car> {

    private String numberPlate; //Número de matrícula
    private String brand; //Marca
    private String version;
    private Integer year;

    public Car(String numberPlate, String brand, String version, Integer year) {
        this.numberPlate = numberPlate;
        this.brand = brand;
        this.version = version;
        this.year = year;
    }

    public Car() {
    }

    public String getNumberPlate() {
        return numberPlate;
    }

    public void setNumberPlate(String numberPlate) {
        this.numberPlate = numberPlate;
    }

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }

    public String getVersion() {
        return version;
    }

    public void setVersion(String version) {
        this.version = version;
    }

    public Integer getYear() {
        return year;
    }

    public void setYear(Integer year) {
        this.year = year;
    }

    @Override
    public String toString() {
        return  "----------------------------------\n" +
                "Matrícula: " + numberPlate + "\n" +
                "Marca: " + brand + "\n" +
                "Version: " + version + "\n" +
                "Año: " + year + "\n";

    }

    @Override
    public int compareTo(Car o) {
        return this.numberPlate.compareTo(o.numberPlate);
    }

}