erreur ds projet hibernate

Bonsoir,
dans mon projet hibernate qui tourne sous myeclipse,
j'ai une nouvelle erreur qui s'affiche malgré que je n'ai rien modifié
et qu'avant tout fonctionne bien :

Code:

1
2
3
4
Exception in thread "main" java.lang.NullPointerException
	at modele.Test.printUser(Test.java:96)
	at modele.Test.listUser(Test.java:55)
	at modele.Test.main(Test.java:15)

malgré l'erreur les données sont enregistrés dans la base de donnée
Test.java:

Code:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
package com.myeclipse.hibernate;
 
import org.hibernate.Transaction;
 
public class HibernateExample {
 
	/**
         * @param args
         */
	public static void main(String[] args) {
		// 1. Add the new user
		addUser();
 
		// 2. Retrieve the user and print it
		listUser();
 
		// 3. Change the user record and update it
		changeUser();
	}
 
	private static void addUser() {
		// 1. Create user
		User user = new User();
		user.setId(1);
		user.setUsername("jdoe");
		user.setPassword("1234");
		user.setFirstName("John");
		user.setLastName("Doe");
		user.setDateCreated(System.currentTimeMillis());
 
		// 2. Create DAO
		UserDAO dao = new UserDAO();
 
		// 3. Start the transaction
		Transaction tx = dao.getSession().beginTransaction();
 
		// 4. Add user
		dao.save(user);
 
		// 5. Commit the transaction (write to database)
		tx.commit();
 
		// 6. Close the session (cleanup connections)
		dao.getSession().close();
	}
 
	private static void listUser() {
		// 1. Create DAO
		UserDAO dao = new UserDAO();
 
		// 2. Find user by ID
		User user = dao.findById(1);
 
		// 3. Print the user information out
		printUser("Printing User, ", user);
 
		// 4. Close the session (cleanup connections)
		dao.getSession().close();
	}
 
	private static void changeUser() {
		// 1. Create DAO
		UserDAO dao = new UserDAO();
 
		// 2. Find user by ID
		User user = dao.findById(1);
 
		// 3. Change user information
		user.setUsername("jsmith");
		user.setPassword("abcd");
		user.setFirstName("Jane");
		user.setLastName("Smith");
 
		// 4. Start the transaction
		Transaction tx = dao.getSession().beginTransaction();
 
		// 5. Update the user record with the changes
		dao.save(user);
 
		// 6. Commit the transaction (write to database)
		tx.commit();
 
		// 7. Load the updated user from the database
		User updatedUser = dao.findById(1);
 
		// 8. Print the updated user information out to confirm the changes
		printUser("Printing Updated User, ", updatedUser);
 
		// 9. Close the session (cleanup connections)
		dao.getSession().close();
	}
 
	private static void printUser(String extraText, User user) {
		System.out.println(extraText 
							+ " User[Username: " 
							+ user.getUsername() 
							+ ", Password: " 
							+ user.getPassword() 
							+ ", First Name: " 
							+ user.getFirstName() 
							+ ", Last Name: " 
							+ user.getLastName() + "]");
	}
 
}

Merci d'avance pour votre aide