How can I prevent Hibernate from updating NULL values

Question

Is there a setting in hibernate to ignore null values of properties when saving a hibernate object?

NOTE
In my case I am de-serial

Answer 1

I have googled a lot about this,but there is no the very solution for me.So,I used a not graceful solution to cover it.

  public void setAccount(Account a) throws HibernateException {
    try {
        Account tmp = (Account) session.
                get(Account.class, a.getAccountId());
        tmp.setEmail(getNotNull(a.getEmail(), tmp.getEmail()));            
        ...
        tmp.setVersion(getNotNull(a.getVersion(), tmp.getVersion()));
        session.beginTransaction();
        session.update(tmp);
        session.getTransaction().commit();
    } catch (HibernateException e) {
        logger.error(e.toString());
        throw e;
    }
}

public static  T getNotNull(T a, T b) {
    return b != null && a != null && !a.equals(b) ? a : b;
}

I receive an Object a which contains a lot of fields.Those field maybe null,but I don't want to update them into mysql. I get an tmp Obejct from db, and change the field by method getNotNull，then update the Object.

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