如何创建 WriteRequest

private static WriteRequest getWriteRequest(EventTracker event) {

    WriteRequest wreq = null;// = new WriteRequest();

    if (event != null) {
        Map<String, AttributeValue> attributeMap = new HashMap<String, AttributeValue>();

        addAttribute(attributeMap, "event_id", event.getEventId());
        addAttribute(attributeMap, "created_datetime", event.getCreatedDatetime());
        addAttribute(attributeMap, "event", event.getEvent());
        addAttribute(attributeMap, "event_type", event.getEventType());
        addAttribute(attributeMap, "response_id", "NULL");

        wreq = new WriteRequest(new PutRequest(attributeMap));
    }
    return wreq;
}

private static void addAttribute(Map<String, AttributeValue> item, String attributeName, String value) {
    AttributeValue attributeValue = new AttributeValue(value);
    item.put(attributeName, attributeValue);
}