1     @Test
 2     public void testPessimisticLock(){
 3         Session session = sf.getCurrentSession();
 4         session.beginTransaction();
 5         
 6         Account a = (Account) session.load(Account.class, 1,LockMode.UPGRADE);//一般用 UPGRADE
 7         int balance = a.getBalance();
 8         //do some caculations
 9         balance -= 10;
10         a.setBalance(balance);
11         
12         session.getTransaction().commit();
13     }

 1 package com.bjsxt.hibernate;
 2 
 3 import javax.persistence.Entity;
 4 import javax.persistence.GeneratedValue;
 5 import javax.persistence.Id;
 6 
 7 @Entity
 8 public class Account {
 9     
10     private Integer id;
11     
12     private int balance;
13 
14     @Id
15     @GeneratedValue
16     public Integer getId() {
17         return id;
18     }
19 
20     public void setId(Integer id) {
21         this.id = id;
22     }
23 
24     public int getBalance() {
25         return balance;
26     }
27 
28     public void setBalance(int balance) {
29         this.balance = balance;
30     }
31     
32 }

 1     @Test
 2     public void testOptimisticLock(){
 3         Session session = sf.openSession();
 4         Session session2 = sf.openSession();
 5         
 6         session.beginTransaction();
 7         Account a1 = (Account) session.load(Account.class, 2);
 8         
 9         session2.beginTransaction();
10         Account a2 = (Account) session2.load(Account.class, 2);
11         
12         a1.setBalance(900);
13         a2.setBalance(1100);
14         
15         session.getTransaction().commit();
16         System.out.println(a1.getVersion());
17         
18         session2.getTransaction().commit();//第二次提交时会对比 version 字段，如果值改变，则事务处理失败，回滚
19         System.out.println(a2.getVersion());
20         
21         session.close();
22         session2.close();
23     }