Problems with I/O object to a File

Question

First of all, hi to everybody, sorry for my English.
I have a problem with my Exam Project. I need to write and read object (Utente) from a file. Following the Class then a Description of the Error/problem
questo � il loader
import java.io.*;
public class Load {
public Load(){}
public void Caricalista(ListKey Lista) throws Exception{
Utente loaded,x;
ObjectInputStream ois = new ObjectInputStream(new FileInputStream ("elenco.sav"));
while((loaded = (Utente)ois.readObject())!=null){
loaded = (Utente)ois.readObject();
System.out.println(loaded.nome);
Lista.insert(loaded);
x=Lista.head();
System.out.println(x.nome);}
ois.close();
Questo il Saver
import java.io.*;
public class Salva {
public Salva(){}
public void salva (Utente piero) throws IOException{
Load loader=new Load();
ListKey Lista=new ListKey();
try{ loader.Caricalista(Lista);
}catch (Exception e){System.out.println ("Errore in Salva.java");}
FileOutputStream fos = new FileOutputStream ("elenco.sav");
ObjectOutputStream oos = new ObjectOutputStream(fos);
Lista.insert(piero);
Utente test=new Utente();
int i;
for(i=0;i<Lista.lenght();i++){
Lista.scorri(test);
oos.writeObject(test);
oos.close();
public class ListKey extends ListNode {
public ListKey() {super();}
public ListKey (Utente o){super(o);}
public ListKey(Utente o, List l){super (o,l);}
public Utente find (String user){if (isEmpty())return null;
if (user.equals(head().nome)) return head();
return ((ListKey)tail()).find(user);
public Utente scorri(Utente prova){if (isEmpty()) return null;
else {prova=head();
return ((ListKey)tail()).scorri(prova);
e il main:
public class mainvia {
* @param args
public static void main(String[] args) {
// TODO Auto-generated method stub
Utente prova=new Utente();
prova.nome="Tettone";
prova.psw="300786";
prova.LibriPrestito="SI";
prova.TitlePrestito1="IL Giovane Holden";
ListKey Lista=new ListKey();
Salva save=new Salva();
try {save.salva(prova);}catch(Exception e){}
Load loader=new Load();
try{loader.Caricalista(Lista);
}catch(Exception e){}
Utente x=new Utente();
System.out.println(x.nome);
The problem is that, if I use only the Load for open the file,it works great and find the first User, instead if in the Salva I run try{ loader.Caricalista(Lista);
}catch (Exception e){System.out.println ("Errore in Salva.java");}
it always goes in Error and print "Errore in Salva.java" like if it can not open the file.
How Can I Resolve?
The base idea is the:
from the mainvia I pass the ListKey Lista to save, then i load all the object from the file to the Lista, then i add to the List the new Object then i write all the object in the List to the file.

Answer 1

Let's start by printing some useful information about the error, instead of just the fact that an error occurred:}catch (Exception e){e.printStackTrace();}Tell us what that produces.