休眠自定義UserType不起作用

我已經創建了一個UserType（見下文）來處理mySQL數據庫中的情況，我們已經將空日期保存爲0000-00-00 00:00:00。休眠自定義UserType不起作用

當我嘗試用dispDT的null（參見下文）持久化實體時，它會生成此異常：「javax.persistence.PersistenceException：org.hibernate.PropertyValueException：not-null屬性引用null或瞬態值：myEntity .dispDt「

通過在MySQLTimeStampUserType中的每個方法中設置一個斷點，我可以看到它調用deepCopy方法並從不調用nullSafeSet方法。我認爲nuyllSafeSet方法的全部重點是讓我在繼續使用之前操縱這個值。我究竟做錯了什麼？

實體批註

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

用戶類型類

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; 
} 
}

來源

2009-10-14 Preston