SQL Server

Refresh Access Token on 401 Unauthorized and Retry (Service Account)

See more Google Cloud Storage Examples

Demonstrates how to handle an expired access token error, refresh the token, and retry the request. (In this case, the request is to download an object from Google Cloud Storage.) SQL Server

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    -- This example requires the Chilkat API to have been previously unlocked.
    -- See Global Unlock Sample for sample code.

    -- This example uses a previously obtained access token having permission for the 
    -- scope "https://www.googleapis.com/auth/cloud-platform"

    -- In this example, Get Google Cloud Storage OAuth2 Access Token, 
    -- the service account access token was saved to a text file.  This example fetches the access token from the file..
    DECLARE @sbToken int
    EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbToken OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    EXEC sp_OAMethod @sbToken, 'LoadFile', @success OUT, 'qa_data/tokens/googleCloudStorageAccessToken.txt', 'utf-8'
    IF @success = 0
      BEGIN

        PRINT 'Failed to load access token.'
        EXEC @hr = sp_OADestroy @sbToken
        RETURN
      END

    DECLARE @http int
    EXEC @hr = sp_OACreate 'Chilkat.Http', @http OUT

    EXEC sp_OAMethod @sbToken, 'GetAsString', @sTmp0 OUT
    EXEC sp_OASetProperty @http, 'AuthToken', @sTmp0

    -- Construct a URL to download an object named "starfish.jpg" from the "chilkat-ocean" bucket.
    EXEC sp_OAMethod @http, 'SetUrlVar', @success OUT, 'bucket_name', 'chilkat-ocean'
    EXEC sp_OAMethod @http, 'SetUrlVar', @success OUT, 'object_name', 'starfish.jpg'
    DECLARE @url nvarchar(4000)
    SELECT @url = 'https://www.googleapis.com/storage/v1/b/{$bucket_name}/o/{$object_name}?alt=media'

    -- If there is an error response, then we didn't actually download the file data,
    -- but instead we downloaded an error response..
    DECLARE @fileData int
    EXEC @hr = sp_OACreate 'Chilkat.BinData', @fileData OUT

    EXEC sp_OAMethod @http, 'DownloadBd', @success OUT, @url, @fileData
    DECLARE @responseCode int
    EXEC sp_OAGetProperty @http, 'LastStatus', @responseCode OUT
    IF (@success = 0) and (@responseCode <> 401)
      BEGIN
        EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbToken
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @fileData
        RETURN
      END

    IF @responseCode = 401
      BEGIN

        PRINT 'Received 401 Unauthorized response. Attempting to refresh the access token...'

        -- May be that the access token expired.
        -- Load our JSON key and request a new access token, then retry the original request.
        DECLARE @fac int
        EXEC @hr = sp_OACreate 'Chilkat.FileAccess', @fac OUT

        DECLARE @jsonKey nvarchar(4000)
        EXEC sp_OAMethod @fac, 'ReadEntireTextFile', @jsonKey OUT, 'qa_data/googleApi/ChilkatCloud-13a07a2e8b3f.json', 'utf-8'
        EXEC sp_OAGetProperty @fac, 'LastMethodSuccess', @iTmp0 OUT
        IF @iTmp0 <> 1
          BEGIN
            EXEC sp_OAGetProperty @fac, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @sbToken
            EXEC @hr = sp_OADestroy @http
            EXEC @hr = sp_OADestroy @fileData
            EXEC @hr = sp_OADestroy @fac
            RETURN
          END

        DECLARE @gAuth int
        EXEC @hr = sp_OACreate 'Chilkat.AuthGoogle', @gAuth OUT

        EXEC sp_OASetProperty @gAuth, 'JsonKey', @jsonKey
        EXEC sp_OASetProperty @gAuth, 'Scope', 'https://www.googleapis.com/auth/cloud-platform'
        EXEC sp_OASetProperty @gAuth, 'ExpireNumSeconds', 3600
        EXEC sp_OASetProperty @gAuth, 'SubEmailAddress', ''

        DECLARE @tlsSock int
        EXEC @hr = sp_OACreate 'Chilkat.Socket', @tlsSock OUT

        EXEC sp_OAMethod @tlsSock, 'Connect', @success OUT, 'www.googleapis.com', 443, 1, 5000
        IF @success <> 1
          BEGIN
            EXEC sp_OAGetProperty @tlsSock, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @sbToken
            EXEC @hr = sp_OADestroy @http
            EXEC @hr = sp_OADestroy @fileData
            EXEC @hr = sp_OADestroy @fac
            EXEC @hr = sp_OADestroy @gAuth
            EXEC @hr = sp_OADestroy @tlsSock
            RETURN
          END

        EXEC sp_OAMethod @gAuth, 'ObtainAccessToken', @success OUT, @tlsSock
        IF @success <> 1
          BEGIN
            EXEC sp_OAGetProperty @gAuth, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @sbToken
            EXEC @hr = sp_OADestroy @http
            EXEC @hr = sp_OADestroy @fileData
            EXEC @hr = sp_OADestroy @fac
            EXEC @hr = sp_OADestroy @gAuth
            EXEC @hr = sp_OADestroy @tlsSock
            RETURN
          END

        EXEC sp_OAGetProperty @gAuth, 'AccessToken', @sTmp0 OUT
        EXEC sp_OAMethod @fac, 'WriteEntireTextFile', @success OUT, 'qa_data/tokens/googleCloudStorageAccessToken.txt', @sTmp0, 'utf-8', 0

        -- Retry the original request.
        EXEC sp_OAGetProperty @gAuth, 'AccessToken', @sTmp0 OUT
        EXEC sp_OASetProperty @http, 'AuthToken', @sTmp0
        EXEC sp_OAMethod @http, 'DownloadBd', @success OUT, @url, @fileData
        IF @success = 0
          BEGIN
            EXEC sp_OAGetProperty @http, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @sbToken
            EXEC @hr = sp_OADestroy @http
            EXEC @hr = sp_OADestroy @fileData
            EXEC @hr = sp_OADestroy @fac
            EXEC @hr = sp_OADestroy @gAuth
            EXEC @hr = sp_OADestroy @tlsSock
            RETURN
          END

      END

    IF @responseCode <> 200
      BEGIN
        -- Get the error response
        DECLARE @sbErrorResponse int
        EXEC @hr = sp_OACreate 'Chilkat.StringBuilder', @sbErrorResponse OUT

        EXEC sp_OAMethod @sbErrorResponse, 'AppendBd', @success OUT, @fileData, 'utf-8', 0, 0

        PRINT 'Error response code = ' + @responseCode

        PRINT 'Error:'
        EXEC sp_OAMethod @sbErrorResponse, 'GetAsString', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @sbToken
        EXEC @hr = sp_OADestroy @http
        EXEC @hr = sp_OADestroy @fileData
        EXEC @hr = sp_OADestroy @fac
        EXEC @hr = sp_OADestroy @gAuth
        EXEC @hr = sp_OADestroy @tlsSock
        EXEC @hr = sp_OADestroy @sbErrorResponse
        RETURN
      END


    PRINT 'Success.'

    -- Save the downloaded data to a file.
    EXEC sp_OAMethod @fileData, 'WriteFile', @success OUT, 'qa_output/starfish.jpg'

    EXEC @hr = sp_OADestroy @sbToken
    EXEC @hr = sp_OADestroy @http
    EXEC @hr = sp_OADestroy @fileData
    EXEC @hr = sp_OADestroy @fac
    EXEC @hr = sp_OADestroy @gAuth
    EXEC @hr = sp_OADestroy @tlsSock
    EXEC @hr = sp_OADestroy @sbErrorResponse


END
GO