What is an example of using OAuth 2.0 and Google Spreadsheet API with Java?

google-api-java-client, google-sheets-api, java, oauth

Solution

Answer moved from original question to match site "Q and A" format.

The `Google Data Java Client Library` supports `OAuth 2.0`. Unfortunately, there are no complete samples in the library showing how to use it with the `Google Spreadsheet API`.

Here is an example that has worked for me. I hope someone find it helpful.

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeRequestUrl;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeTokenRequest;
import com.google.api.client.googleapis.auth.oauth2.GoogleCredential;
import com.google.api.client.googleapis.auth.oauth2.GoogleTokenResponse;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.http.javanet.NetHttpTransport;
import com.google.api.client.json.jackson.JacksonFactory;
import com.google.gdata.util.ServiceException;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.List;

public class NewClass {

  // Retrieve the CLIENT_ID and CLIENT_SECRET from an APIs Console project:
  //     https://code.google.com/apis/console
  static String CLIENT_ID = "your-client-id";
  static String CLIENT_SECRET = "your-client-secret";
  // Change the REDIRECT_URI value to your registered redirect URI for web
  // applications.
  static String REDIRECT_URI = "the-redirect-uri";
  // Add other requested scopes.
  static List<String> SCOPES = Arrays.asList("https://spreadsheets.google.com/feeds");


public static void main (String args[]) throws IOException, ServiceException, com.google.protobuf.ServiceException{
    Credential credencial = getCredentials();
    JavaApplication20.printDocuments(credencial);
}


  /**
   * Retrieve OAuth 2.0 credentials.
   * 
   * @return OAuth 2.0 Credential instance.
   */
  static Credential getCredentials() throws IOException {
    HttpTransport transport = new NetHttpTransport();
    JacksonFactory jsonFactory = new JacksonFactory();

    // Step 1: Authorize -->
    String authorizationUrl =
        new GoogleAuthorizationCodeRequestUrl(CLIENT_ID, REDIRECT_URI, SCOPES).build();

    // Point or redirect your user to the authorizationUrl.
    System.out.println("Go to the following link in your browser:");
    System.out.println(authorizationUrl);

    // Read the authorization code from the standard input stream.
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    System.out.println("What is the authorization code?");
    String code = in.readLine();
    // End of Step 1 <--

    // Step 2: Exchange -->
    GoogleTokenResponse response =
        new GoogleAuthorizationCodeTokenRequest(transport, jsonFactory, CLIENT_ID, CLIENT_SECRET,
            code, REDIRECT_URI).execute();
    // End of Step 2 <--

    // Build a new GoogleCredential instance and return it.
    return new GoogleCredential.Builder().setClientSecrets(CLIENT_ID, CLIENT_SECRET)
        .setJsonFactory(jsonFactory).setTransport(transport).build()
     .setAccessToken(response.getAccessToken()).setRefreshToken(response.getRefreshToken());
  }

  // …
}

Here the other Class:

import com.google.api.client.auth.oauth2.Credential;
import com.google.gdata.client.docs.DocsService;
import com.google.gdata.client.spreadsheet.SpreadsheetService;
import com.google.gdata.data.docs.DocumentListEntry;
import com.google.gdata.data.docs.DocumentListFeed;
import com.google.gdata.data.docs.SpreadsheetEntry;
import com.google.gdata.data.spreadsheet.CellEntry;
import com.google.gdata.data.spreadsheet.CellFeed;
import com.google.gdata.data.spreadsheet.SpreadsheetFeed;
import com.google.gdata.data.spreadsheet.WorksheetEntry;
import com.google.gdata.data.spreadsheet.WorksheetFeed;
import com.google.gdata.util.ServiceException;
// ...
import java.io.IOException;
import java.net.URL;
import java.util.List;
// ...

public class JavaApplication20 {
  // …

  static void printDocuments(Credential credential) throws IOException, ServiceException {
    // Instantiate and authorize a new SpreadsheetService object.

     SpreadsheetService service =
            new SpreadsheetService("Aplication-name");
     service.setOAuth2Credentials(credential);
    // Send a request to the Documents List API to retrieve document entries.
    URL SPREADSHEET_FEED_URL = new URL(
        "https://spreadsheets.google.com/feeds/spreadsheets/private/full");
    // Make a request to the API and get all spreadsheets.
    SpreadsheetFeed feed = service.getFeed(SPREADSHEET_FEED_URL,
        SpreadsheetFeed.class);
    List<com.google.gdata.data.spreadsheet.SpreadsheetEntry> spreadsheets = feed.getEntries();
     if (spreadsheets.isEmpty()) {
      // TODO: There were no spreadsheets, act accordingly.
    }
com.google.gdata.data.spreadsheet.SpreadsheetEntry spreadsheet = spreadsheets.get(0);
    System.out.println(spreadsheet.getTitle().getPlainText());
// Get the first worksheet of the first spreadsheet.
    // TODO: Choose a worksheet more intelligently based on your
    // app's needs.
    WorksheetFeed worksheetFeed = service.getFeed(
        spreadsheet.getWorksheetFeedUrl(), WorksheetFeed.class);
    List<WorksheetEntry> worksheets = worksheetFeed.getEntries();
    WorksheetEntry worksheet = worksheets.get(0);

    // Fetch the cell feed of the worksheet.
    URL cellFeedUrl = worksheet.getCellFeedUrl();
    CellFeed cellFeed = service.getFeed(cellFeedUrl, CellFeed.class);

    // Iterate through each cell, printing its value.
    for (CellEntry cell : cellFeed.getEntries()) {
      // Print the cell's address in A1 notation
      System.out.print(cell.getTitle().getPlainText() + "\t");
      // Print the cell's address in R1C1 notation
      System.out.print(cell.getId().substring(cell.getId().lastIndexOf('/') + 1) + "\t");
      // Print the cell's formula or text value
      System.out.print(cell.getCell().getInputValue() + "\t");
      // Print the cell's calculated value if the cell's value is numeric
      // Prints empty string if cell's value is not numeric
      System.out.print(cell.getCell().getNumericValue() + "\t");
      // Print the cell's displayed value (useful if the cell has a formula)
      System.out.println(cell.getCell().getValue() + "\t");
    }

  }

  // ...
}

Problem

Where is example code showing how to use the `Google Data Java Client Library` and its support for `OAuth 2.0` with the `Google Spreadsheet API` (now called the `Google Sheets API`)?

Original source