java – 乐观锁定和org.hibernate.StaleObjectStateException：

我有以下课程：

@Entity
public class Student {

    private Integer id;
    private String firstName;
    private String lastName;
    private Integer version; 
@Version
    public Integer getVersion() {
        return version;
    }

//all other getters ommited.
}

现在我正在抓住其中一个学生并尝试同时更新其属性.

Thread t1 = new Thread(new MyRunnable(id));
    Thread t2 = new Thread(new MyRunnable(id));
    t1.start();
    t2.start();

和MyRunnable内部：

public class MyRunnable implements Runnable {
    private Integer id;
    @Override
    public void run() {
        Session session = HibernateUtil.getSessionFactory().openSession();       
        session.beginTransaction();
        Student student = (Student) session.load(Student.class,id);
        student.setFirstName("xxxx");
        session.save(student);
        session.getTransaction().commit();
        System.out.println("Done"); 
    }

    public MyRunnable(Integer id){
        this.id = id;
    }
}

第一个事务成功更新对象和第二个事务抛出的情况：

org.hibernate.staleobjectstateexception: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.vanilla.entity.Student#1]

还行吧.

我的问题是：
1)如果我希望第二个事务什么也不做,并且不抛出任何异常,我该怎么办？

2)如果我希望第二个事务覆盖第一个事务更新的数据,我该怎么办？

谢谢.