Renren OAuth 2.0 Example using Scribe Java

In this example we are going to see about how to use Renren OAuth2.0 using Scribe Java
Renren OAuth2.0 Example using Scribe

RenrenExample.java
import java.nio.charset.Charset;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import com.github.scribejava.core.builder.ServiceBuilder;
import com.github.scribejava.apis.RenrenApi;
import com.github.scribejava.core.model.OAuth2AccessToken;
import com.github.scribejava.core.model.OAuthConstants;
import com.github.scribejava.core.model.OAuthRequest;
import com.github.scribejava.core.model.Response;
import com.github.scribejava.core.model.Verb;
import com.github.scribejava.core.oauth.OAuth20Service;
import java.io.IOException;

public abstract class RenrenExample {

    private static final String NETWORK_NAME = "Renren";
    private static final String PROTECTED_RESOURCE_URL = "http://api.renren.com/restserver.do";

    public static void main(String... args) throws IOException {
        // Replace these with your own api key and secret
        final String apiKey = "your api key";
        final String apiSecret = "your api secret";
        final OAuth20Service service = new ServiceBuilder()
                .apiKey(apiKey)
                .apiSecret(apiSecret)
                .scope("status_update publish_feed")
                .callback("http://your.doman.com/oauth/renren")
                .build(RenrenApi.instance());
        final Scanner in = new Scanner(System.in);

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

        // Obtain the Authorization URL
        System.out.println("Fetching the Authorization URL...");
        final String authorizationUrl = service.getAuthorizationUrl();
        System.out.println("Got the Authorization URL!");
        System.out.println("Now go and authorize ScribeJava here:");
        System.out.println(authorizationUrl);
        System.out.println("And paste the authorization code here");
        System.out.print(">>");
        final String code = 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...");
        final OAuth2AccessToken accessToken = service.getAccessToken(code);
        System.out.println("Got the Access Token!");
        System.out.println("(if your curious it looks like this: " + accessToken
                + ", 'rawResponse'='" + accessToken.getRawResponse() + "')");
        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...");
        final OAuthRequest request = new OAuthRequest(Verb.POST, PROTECTED_RESOURCE_URL, service);
        final Map parameters = new HashMap<>();
        parameters.put("method", "users.getInfo");
        parameters.put("format", "json");
        parameters.put("v", "1.0");

        final List sigString = new ArrayList<>(parameters.size() + 1);
        for (Map.Entry entry : parameters.entrySet()) {
            request.addQuerystringParameter(entry.getKey(), entry.getValue());
            sigString.add(String.format("%s=%s", entry.getKey(), entry.getValue()));
        }
        sigString.add(String.format("%s=%s", OAuthConstants.ACCESS_TOKEN, accessToken.getAccessToken()));
        Collections.sort(sigString);
        final StringBuilder b = new StringBuilder();
        for (String param : sigString) {
            b.append(param);
        }
        b.append(apiSecret);
        System.out.println("Sig string: " + b.toString());
        request.addQuerystringParameter("sig", md5(b.toString()));
        service.signRequest(accessToken, request);
        final 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 ScribeJava! :)");

    }

    public static String md5(String orgString) {
        try {
            final MessageDigest md = MessageDigest.getInstance("MD5");
            final byte[] array = md.digest(orgString.getBytes(Charset.forName("UTF-8")));
            final StringBuffer sb = new StringBuffer();
            for (int i = 0; i < array.length; ++i) {
                sb.append(Integer.toHexString((array[i] & 0xFF) | 0x100).substring(1, 3));
            }
            return sb.toString();
        } catch (NoSuchAlgorithmException e) {
            e.printStackTrace();
        }
        return null;
    }

}