String CLIENT_ID = "" , CLIENT_SECRET = "";
List<String> scopes = new ArrayList<String>();
scopes.add("data:read");
scopes.add("data:write");

// Initialize the 2-legged OAuth 2.0 client, and optionally set specific scopes.
// If you omit scopes, the generated token will have all scope permissions.
// Set autoRefresh to `true` to automatically refresh the access token when it expires.
OAuth2TwoLegged oauth2TwoLegged = new OAuth2TwoLegged(CLIENT_ID, CLIENT_SECRET, scopes, true);
Credentials twoLeggedCredentials = oauth2TwoLegged.authenticate();

String CLIENT_ID = "" , CLIENT_SECRET = "", REDIRECT_URL = "";
// Generate a url that asks permissions for specific scopes.
List<String> scopes = new ArrayList<String>();
scopes.add("data:read");
scopes.add("data:write");

// Initialize the 3-legged OAuth 2.0 client, and optionally set specific scopes.
// If you omit scopes, the generated token will have all scope permissions.
// Set autoRefresh to `true` to automatically refresh the access token when it expires.
// Note that the REDIRECT_URL must match the callback URL you provided when you created the app.
OAuth2ThreeLegged oauth2ThreeLegged = new OAuth2ThreeLegged(CLIENT_ID, CLIENT_SECRET, REDIRECT_URL, scopes, true);

// Generate a URL page that asks for permissions for the specified scopes.
String oauthUrl = oauth2ThreeLegged.getAuthenticationUrl();

//Redirect the user to authUrl (the user consent page).

// The `threeLeggedCredentials` object contains an `access_token` and an optional `refresh_token` that you can use to call the endpoints.
ThreeLeggedCredentials threeLeggedCredentials = oauth2ThreeLegged.getAccessToken(authorizationCode);

import com.autodesk.client.ApiException;
import com.autodesk.client.ApiResponse;
import com.autodesk.client.api.BucketsApi;
import com.autodesk.client.api.HubsApi;
import com.autodesk.client.auth.*;
import com.autodesk.client.model.*;
import java.util.ArrayList;
import java.util.List;

public class ForgeApiExample {

    public static void main(String[] args) {

        try {
            List<String> scopes = new ArrayList<String>();
            scopes.add("data:read");
            scopes.add("data:write");
            scopes.add("bucket:create");
            scopes.add("bucket:read");

            // Initialize the oauth2TwoLegged object using the client key and client secret you received when creating the app on the Forge Developer portal:
            OAuth2TwoLegged oauth2TwoLegged = new OAuth2TwoLegged("<CLIENT_ID>", "<CLIENT_SECRET>", scopes, true);
            Credentials twoLeggedCredentials = oauth2TwoLegged.authenticate();

            // Initialize the relevant clients; in this example, the Hubs and Buckets clients (part of the Data Management API).
            BucketsApi bucketsApi = new BucketsApi();
            HubsApi hubsApi = new HubsApi();

            // Create a new bucket
            // Use the oauth2TwoLegged and twoLeggedCredentials objects that you retrieved previously.
            PostBucketsPayload payload = new PostBucketsPayload();
            payload.setBucketKey("test_bucket_key");
            payload.setPolicyKey(PostBucketsPayload.PolicyKeyEnum.PERSISTENT);
            ApiResponse<Bucket> createBucketResponse = bucketsApi.createBucket(payload, "", oauth2TwoLegged, twoLeggedCredentials);
            System.out.println(createBucketResponse.getData().getBucketKey());

            // Get the buckets owned by an application.
            // Use the oauth2TwoLegged and twoLeggedCredentials objects that you retrieved previously.
            ApiResponse<Buckets> getBucketsResponse = bucketsApi.getBuckets(null, null, null, oauth2TwoLegged, twoLeggedCredentials);
            for(BucketsItems bucket: getBucketsResponse.getData().getItems()) {
                System.out.println(bucket.getBucketKey());
            }

            // Get the hubs that are accessible for a member.
            // Use the oauth2ThreeLegged and threeLeggedCredentials objects that you retrieved previously.
            ApiResponse<Hubs> getHubsResponse = hubsApi.getHubs(null, null, oauth2ThreeLegged, threeLeggedCredentials);
            for(Hub hub: getHubsResponse.getData().getData()) {
                System.out.println(hub.getId());
            }

        } catch (Exception e) {
            System.err.println("Exception when calling Forge APIs");
            e.printStackTrace();
        }
    }
}