Changes:getStartCursor

Function

Obtains the starting cursor.

Scenario

By calling the Changes.getStartCursor API, your app can obtain the starting cursor required by the Changes.subscribe API.

Restrictions

The value of scope must be one of the following:

https://www.huawei.com/auth/drive.appdata
https://www.huawei.com/auth/drive.file
https://www.huawei.com/auth/drive
https://www.huawei.com/auth/drive.readonly
https://www.huawei.com/auth/drive.metadata
https://www.huawei.com/auth/drive.metadata.readonly

Prototype

Protocol	HTTP GET
Direction	Developer server -> HUAWEI Drive server
URL	https://driveapis.cloud.huawei.com.cn/drive/v1/changes/getStartCursor
Data Format	Request: Content-Type: application/json Response: Content-Type: application/json

Path Parameters

None.

Query Parameters

Parameter	Mandatory/Optional	Type	Description
fields	Mandatory	string	Fields in the request, which are in the partial response format. For details, please refer to Overview.
form	Optional	string	Media format.
prettyPrint	Optional	boolean	Indicates whether to return a response in a human-readable format.
quotaId	Optional	string	User identifier, which can contain a maximum of 40 characters. This parameter is used to restrict the maximum number of API calls for a single user.
callback	Optional	string	Callback function used in JSONP requests.

Request Parameters

Request Header

Parameter	Mandatory/Optional	Type	Description
x-hw-trace-id	Optional	string	ID used for service tracing.
x-hw-app-id	Optional	string	App ID.
version	Optional	string	SDK version number.
x-hw-terminal	Optional	string	Device model.
x-hw-os	Optional	string	Device operating system.
unionID	Optional	string	User's UnionID.
User-Agent	Optional	string	App version number or app ID.
x-hw-deviceUUID	Optional	string	UUID of the device.
x-hw-deviceUDID	Optional	string	UDID of the device.
x-hw-appPackageName	Optional	string	App package name.
x-hw-network	Optional	string	Network type. The options include WiFi, 2G, 3G, 4G, 5G, and wire.

Request Body

None.

Request Example

GET  https://driveapis.cloud.huawei.com.cn/drive/v1/changes/getStartCursor?fields=*    HTTP/1.1 
Content-Type: application/json 
Authorization: Bearer CV3PnPLZXyr9K2GV7RYZkF962JZvoEkMQhTho3QHQAPQUyma/lEyZskP/IMWrc7FvaeHivO7y0lyibI/fQvulBnTgtXArSVPsjaLKvYNkDsJSaIR2/sx+K40bYDWWpKFvJNKg2U47jRwz2mfiF3ortNk 
Cache-Control: no-cache

Response Parameters

When the status code is 200:

Parameter	Type	Description
category	string	Resource type. The value is always drive#startCursor.
startCursor	string	Starting cursor.

Response Example

{
            "category": "drive#startCursor",
            "startCursor": "238247332125117440"
}

Result Code

Status Code	Result Code	Response Code	Description
200	NA	-	Success.
500	21055002	OUTER_SERVICE_UNAVAILABLE	External service is unavailable.
500	21005006	SERVER_TEMP_ERROR	Temporary server error.
403	21074033	AGREEMENT_NOT_SIGNED	The HUAWEI Drive user agreement is not signed. Try again after the agreement is signed.

For details about other result codes, please refer to Status Codes.

Call Example

   public static void main(String[] args) throws IOException {
        // Set the request URL and access token.
        String url = "https://driveapis.cloud.huawei.com.cn/drive/v1/changes/getStartCursor";
        String access_token = "CV5OUVN/e79TSba9Kaxlgx+TONKyYovWvre8BZM05oh6J51jBIbeYp0FRSuLcFBZoDaft0V/B+m+mPFf7MG3n8JmO8w3n6/K6zUI8I5/auSzdxv8GOdAPw==";
        // Obtain the starting cursor.
        JSONObject cursorInfo = changesGetStartCursor(url, access_token);
        System.out.println(cursorInfo.toJSONString());
    }

    private static JSONObject changesGetStartCursor(String url, String access_token) throws IOException {
        StringBuilder stringBuilder = new StringBuilder("");
        stringBuilder.append("?").append("fields=*");
        HttpGet httpGet = new HttpGet(url + stringBuilder);
        httpGet.setHeader("Authorization","Bearer " + access_token);
        CloseableHttpResponse response = HttpClientUtil.getClient().execute(httpGet);

        try {
            HttpEntity responseEntity = response.getEntity();
            String ret = responseEntity != null ? EntityUtils.toString(responseEntity) : null;
            JSONObject jsonObject = (JSONObject) JSON.parse(ret);
            EntityUtils.consume(responseEntity);
            return jsonObject;
        }finally {
            response.close();
        }
    }

目录