package traitement;

import java.util.*;

/**
 * 
 */
public abstract class Constante {

    /**
     * Default constructor
     */
    public Constante() {
    }

    /**
     * 
     */
    private static int nbAscenseur;

    public static int getNbEtage() {
        return nbEtage;
    }

    /**
     * 
     */
    private static int nbEtage;


}

package ascenceur.traitement;

import java.util.*;

public abstract class Constante {

    private static final int nbAscenceurMax = 10;
    private static final int nbEtage = 20;

    public static final int getNbEtage() {
        return nbEtage;
    }

    public static final int getNbAscenceur() {
        return nbAscenceurMax;
    }
}

Update Constante.java