休眠自定义UserType不起作用

我已经创建了一个UserType（见下文）来处理mySQL数据库中的情况，我们已经将空日期保存为0000-00-00 00:00:00。休眠自定义UserType不起作用

当我尝试用dispDT的null（参见下文）持久化实体时，它会生成此异常：“javax.persistence.PersistenceException：org.hibernate.PropertyValueException：not-null属性引用null或瞬态值：myEntity .dispDt“

通过在MySQLTimeStampUserType中的每个方法中设置一个断点，我可以看到它调用deepCopy方法并从不调用nullSafeSet方法。我认为nuyllSafeSet方法的全部重点是让我在继续使用之前操纵这个值。我究竟做错了什么？

实体批注

@Basic(optional = false) 
@Column(name = "disp_dt") 
@Type(type = "mypackage.MySQLTimeStampUserType") 
// @Temporal(TemporalType.TIMESTAMP) 
private Date dispDt;

用户类型类

public class MySQLTimeStampUserType implements UserType { 

private static final int[] SQL_TYPES = {Types.TIMESTAMP}; 

public int[] sqlTypes() { 
    return SQL_TYPES; 
} 

public Class returnedClass() { 
    return Date.class; 
} 

public boolean equals(Object x, Object y) throws HibernateException { 
    if (x == y) { 
     return true; 
    } else if (x == null || y == null) { 
     return false; 
    } else { 
     return x.equals(y); 
    } 

} 

public int hashCode(Object arg0) throws HibernateException { 
    throw new UnsupportedOperationException("Not supported yet."); 
} 

public Object nullSafeGet(ResultSet resultSet, String[] names, Object owner) throws HibernateException, SQLException { 
    // if the date is 0000-00-00 00:00:00 return null, else return the timestamp 
    Date result = null; 
    if (!resultSet.wasNull()) { 
     if (!resultSet.getString(names[0]).equals("0000-00-00 00:00:00")) { 
      result = resultSet.getDate(names[0]); 
     } 
    } 
    return result; 
} 

public void nullSafeSet(PreparedStatement statement, Object value, int index) throws HibernateException, SQLException { 
    // if the date is null set the value to "0000-00-00 00:00:00" else save the timestamp 
    if (value == null) { 
     statement.setString(index, "0000-00-00 00:00:00"); 
    } else { 
     statement.setTimestamp(index,(Timestamp) value); 
    } 

} 

public Object deepCopy(Object value) throws HibernateException { 
    return value; 
} 

public boolean isMutable() { 
    return false; 
} 

public Serializable disassemble(Object value) throws HibernateException { 
    throw new UnsupportedOperationException("Not supported yet."); 
} 

public Object assemble(Serializable cached, Object owner) throws HibernateException { 
    throw new UnsupportedOperationException("Not supported yet."); 
} 

public Object replace(Object original, Object target, Object owner) throws HibernateException { 
    return original; 
} 
}

来源

2009-10-14 Preston