spreadsheet

Sources : Spread sheet reference, OAuth for web server applications

How to access google spreadsheets in web application.

• 0. Create client on google-credentials page for our app (I prefered OAuth client).
  • This will require decision for scopes(service + scope , e.g- spreadsheet read only.) our app will be using.
  • Also, an end-point URL on our app, that will be used for redirection from Google auth server. This endpoint should support GET and POST methods and accept javax.servlet.http.HttpServletRequest along being ssl enabled.
• 1. Construct consent-request-URL and ask application user to hit same, so that user approves required access.
  • This URL consists of client-id, scope and redirection-URL(of our app). e.g- https://accounts.google.com/o/oauth2/v2/auth?scope=<SCOPE_TO_USE>&access_type=offline&include_granted_scopes=true&state=state_parameter_passthrough_value&redirect_uri=<REDIRECTION_URL>&response_type=code&client_id=<CLIENT_ID>
  • Google consent request will redirect user to redirection endpoint URL.
    • If User approves the consent requests, redirection will contain code else error.
• 2. Endpoint should should extract code from request object and POST another request for token generation to "https://www.googleapis.com/oauth2/v4/token".
  • This request will have client-id, client-secret, code, grant-type and same redirection URL.
  • This request returns json object as response body containing access_token.
• 3. Next we need to initialize desired (one sent in scope) Google API Service ( in our use case - com.google.api.services.sheets.v4.Sheets ) .
  • This uses com.google.api.client.googleapis.javanet.GoogleNetHttpTransport.newTrustedTransport(), com.google.api.client.json.jackson2.JacksonFactory.getDefaultInstance() and instance of com.google.api.client.googleapis.auth.oauth2.GoogleCredential with access token set.
  • later use service. In our application, obtain values from provided sheet id and cell ranges.

Sample project on github

search texts: read google spread sheet data from java, spring boot application.

Access google spreadsheet data from java, spring boot application.

OAuth for web applications.