如何断开对象与它的连接'；grails中的hibernate会话？

我正试图这样做，但我得到了错误

“具有相同标识符值的不同对象已与会话关联”

看起来我需要从hibernate会话中删除dbObject

def object = messageParserService.parseMessage(messageType, messageText)
def dbObject = object.getClass().findByIdentifier(object.identifier)
if(dbObject != null){
    object.id = dbObject.id
    object.dateCreated = dbObject.dateCreated
}
if(!object.save()) {
    object.errors.each {println it}
}

dbObject.discard（）成功了

def object = messageParserService.parseMessage(messageType, messageText)
def dbObject = object.getClass().findByIdentifier(object.identifier)
if(dbObject != null){
    object.id = dbObject.id
    object.dateCreated = dbObject.dateCreated
    dbObject.discard()
}
if(!object.save()) {
    object.errors.each {println it}
}

看