Digg oAuth using Scribe

I really like the Scribe library for doing oAuth in Java.  It uses a fluent API, a very slim dependency structure, and is ready to use in android apps.  So, when I needed to connect to Digg’s API for a Java app, I looked at Scribe first.

Unfortunately, Scribe doesn’t support Digg out of the box (it does however, support Facebook, Yahoo, FourSquare, Vimeo, and many others).  Adding support for a new service is simple.

Lets start with a sample client application:

package org.scribe.examples;

import java.util.Scanner;

import org.scribe.builder.ServiceBuilder;
import org.scribe.builder.api.DiggApi;
import org.scribe.model.*;
import org.scribe.oauth.OAuthService;

public class DiggExample {
  private static final String NETWORK_NAME = "Digg";
  private static final String PROTECTED_RESOURCE_URL = "http://services.digg.com/2.0/comment.digg";

  public static void main(String[] args) {
    // Replace these with your own api key and secret
    String apiKey = "myKey";
    String apiSecret = "mySecret";
    OAuthService service = new ServiceBuilder().provider(DiggApi.class).apiKey(apiKey).apiSecret(apiSecret).build();
    Scanner in = new Scanner(System.in);

    System.out.println("=== " + NETWORK_NAME + "'s OAuth Workflow ===");
    System.out.println();

    // Obtain the Request Token
    System.out.println("Fetching the Request Token...");
    Token requestToken = service.getRequestToken();
    System.out.println("Got the Request Token!");
    System.out.println();

    // Obtain the Authorization URL
    System.out.println("Fetching the Authorization URL...");
    String authorizationUrl = service.getAuthorizationUrl(requestToken);
    System.out.println("Got the Authorization URL!");
    System.out.println("Now go and authorize Scribe here:");
    System.out.println(authorizationUrl);
    System.out.println("And paste the authorization code here");
    System.out.print(">>");
    Verifier verifier = new Verifier(in.nextLine());
    System.out.println();

    // Trade the Request Token and Verfier for the Access Token
    System.out.println("Trading the Request Token for an Access Token...");
    Token accessToken = service.getAccessToken(requestToken, verifier);
    System.out.println("Got the Access Token!");
    System.out.println("(if your curious it looks like this: " + accessToken + " )");
    System.out.println();

    // Now let's go and ask for a protected resource!
    System.out.println("Now we're going to access a protected resource...");
    OAuthRequest request = new OAuthRequest(Verb.POST, PROTECTED_RESOURCE_URL);
    request.addBodyParameter("comment_id", "20100729223726:4fef610331ee46a3b5cbd740bf71313e");
    service.signRequest(accessToken, request);
    Response response = request.send();
    System.out.println("Got it! Lets see what we found...");
    System.out.println();
    System.out.println(response.getCode());
    System.out.println(response.getBody());

    System.out.println();
    System.out.println("Thats it man! Go and build something awesome with Scribe! :)");

  }
}

Simple enough – pay special attention to line 18. This is scribe’s fluent api for setting up the oAuth provider. After that, we have a pretty simple workflow – get a request token, ask the user to authorize the application, and trade the request token in for an access token.

The code to make this all work is even easier. Scribe provides 2 base classes – DefaultApi10a and DefaultApi20 (for oAuth v1.0a and oAuth v2 respectively). Since Digg’s api uses oAuth v1, we just extend DefaultApi10a and plug in the right info, like so:

package org.scribe.builder.api;

import org.scribe.model.Token;

public class DiggApi extends DefaultApi10a {

  private static final String AUTHORIZATION_URL = "http://digg.com/oauth/authorize?oauth_token=%s";
  private static final String BASE_URL = "http://services.digg.com/oauth/";

  @Override
  public String getRequestTokenEndpoint() {
    return BASE_URL + "request_token";
  }

  @Override
  public String getAccessTokenEndpoint() {
    return BASE_URL + "access_token";
  }

  @Override
  public String getAuthorizationUrl(Token requestToken) {
    return String.format(AUTHORIZATION_URL, requestToken.getToken());
  }
}

Thats it, we’re done. You can get the code here