javax.naming.NoInitialContextException HELP!

[jurian]

Ciao a tutti ragazzi! Sto scrivendo un semplice esercizio per ejb ma mi da sempre questo errore (ho provato anche con programmi funzionanti su altri computer ma sul mio persiste sempre questo errore che ora vi allego)
Premetto che sto usando netbeans con glassfish
L'errore è:

javax.naming.NoInitialContextException: Need to specify class name in environment or system property, or as an applet parameter, or in an application resource file:  java.naming.factory.initial
    at javax.naming.spi.NamingManager.getInitialContext(NamingManager.java:662)
    at javax.naming.InitialContext.getDefaultInitCtx(InitialContext.java:313)
    at javax.naming.InitialContext.getURLOrDefaultInitCtx(InitialContext.java:350)
    at javax.naming.InitialContext.lookup(InitialContext.java:417)
    at fornitoriclientejb.FornitoriClientEJB.main(FornitoriClientEJB.java:32)

CODICE: 
// classe FornitoriClientEJB


package fornitoriclientejb;
import esame.FornitoreEJBRemote;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;


public class FornitoriClientEJB {
    public static final Logger log = Logger.getGlobal();
    
    public static void main(String[] args){
        try {
            log.info("Inizio...");
            Context ctx;
            ctx = new InitialContext();
            log.info("Contesto creato ");
            log.info("faccio lookup");
            FornitoreEJBRemote ejbf = (FornitoreEJBRemote)ctx.lookup("java:global/Fornitori/FornitoreEJB!esame.FornitoreEJBRemote");
            log.info("tutto apposto");
         
        } catch (NamingException ex) {
            Logger.getLogger(FornitoriClientEJB.class.getName()).log(Level.SEVERE, null, ex);
        }
        
    }


}

// classe DatabasePopulator
package esame;


import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.sql.DataSourceDefinition;
import javax.ejb.EJB;
import javax.ejb.Singleton;
import javax.ejb.Startup;




@Singleton
@Startup
@DataSourceDefinition(
        className ="org.apache.derby.jdbc.EmbeddedDataSource",
        name ="java:global/jdbc/EsameDS",
        user ="APP",
        password ="APP",
        databaseName ="EsameDB",
        properties ={"connectionAttributes =;crate=true"}


)
public class DatabasePopulator {
    @EJB
    private FornitoreEJB ejb;
    private Fornitore f1,f2;
    
    @PostConstruct
    private void populatedDB(){
        f1 = new Fornitore("123", "nome1", "cognome1", 23, 5);
        f2 = new Fornitore("3456", "nome2", "cognome2", 3, 1);
        ejb.createFornitore(f1);
        ejb.createFornitore(f2);
    }
    
    @PreDestroy
    private void clearDB(){
        ejb.deleteFornitore(f1);
        ejb.deleteFornitore(f2);
    }
}


//classe databaseProducer


package esame;


import javax.enterprise.inject.Produces;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;


public class DatabaseProducer {
    @Produces
    @PersistenceContext(unitName = "FornitoriPU")
    private EntityManager em;
    
}

// classe Fornitoreejbpackage esame;


import java.util.List;
import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.inject.Inject;
import javax.persistence.EntityManager;
import javax.persistence.TypedQuery;




@Stateless
@LocalBean
public class FornitoreEJB implements FornitoreEJBRemote {
    
    @Inject 
    private EntityManager em;


    @Override
    public List<Fornitore> findALLFornitore() {
       TypedQuery<Fornitore> query = em.createNamedQuery("Fornitore.findALL",Fornitore.class);
       return query.getResultList();
    }


    @Override
    public List<Fornitore> findOrdermax(int max) {
        TypedQuery<Fornitore> query = em.createNamedQuery("Fornitore.findMaxOrder",Fornitore.class);
        query.setParameter(3,max);
        return query.getResultList();
    }


    @Override
    public Fornitore findID(String id) {
        TypedQuery<Fornitore> query = em.createNamedQuery("Fornitore.findID",Fornitore.class);
        query.setParameter(1, id);
        return query.getSingleResult();
    }


    @Override
    public Fornitore findCognome(String cognome) {
        TypedQuery<Fornitore>query = em.createNamedQuery("Fornitore.findCognome",Fornitore.class);
        query.setParameter(2, cognome);
        return query.getSingleResult();
    }


    @Override
    public Fornitore createFornitore(Fornitore f) {
        em.persist(f);
         return f;
    }


    @Override
    public Fornitore updateFornitore(Fornitore f) {
        return em.merge(f);
    }


    @Override
    public Fornitore incrementaOrdini(String id, int i) {
       Fornitore f = this.findID(id);
       f.setValoteTotOrdini(f.getValoteTotOrdini()+i);
       return f;
    }


    @Override
    public void deleteFornitore(Fornitore f) {
         em.remove(em.merge(f));
    }


}


//classe fornitore


package esame;


import java.io.Serializable;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.NamedQueries;
import javax.persistence.NamedQuery;
import javax.validation.constraints.NotNull;


@Entity
@NamedQueries({
    @NamedQuery(name="Fornitore.findALL",query="SELECT f FROM Fornitore f"),
    @NamedQuery(name="Fornitore.findID",query="SELECT f FROM Fornitore f WHERE f.id=?1"),
    @NamedQuery(name="Fornitore.findCognome",query="SELECT f FROM Fornitore f WHERE f.cognome =?2"),
    @NamedQuery(name="Fornitore.findMaxOrder",query="SELECT f FROM Fornitore f WHERE f.maxOrder >?3")
})
public class Fornitore implements Serializable {
  
    @Id
    private String id;
    @NotNull
    private String nome;
    @NotNull
    private String cognome;
    @NotNull
    private int maxOrder;
    @NotNull
    private int valoteTotOrdini;


    public Fornitore() {
    }


    public Fornitore(String id, String nome, String cognome, int maxOrder, int valoteTotOrdini) {
        this.id = id;
        this.nome = nome;
        this.cognome = cognome;
        this.maxOrder = maxOrder;
        this.valoteTotOrdini = valoteTotOrdini;
    }


    public String getId() {
        return id;
    }


    public void setId(String id) {
        this.id = id;
    }


    public String getNome() {
        return nome;
    }


    public void setNome(String nome) {
        this.nome = nome;
    }


    public String getCognome() {
        return cognome;
    }


    public void setCognome(String cognome) {
        this.cognome = cognome;
    }


    public int getMaxOrder() {
        return maxOrder;
    }


    public void setMaxOrder(int maxOrder) {
        this.maxOrder = maxOrder;
    }


    public int getValoteTotOrdini() {
        return valoteTotOrdini;
    }


    public void setValoteTotOrdini(int valoteTotOrdini) {
        this.valoteTotOrdini = valoteTotOrdini;
    }


}

Aiuto!!