A Java application to demonstrate authenticating with the Campaign Monitor API using OAuth. Uses the createsend-java library as well as the Spark micro web framework (but could easily be adapted for use with any Java web application framework).

CreateSendOAuthTest.java

// Ensure you set the CREATESEND_CLIENT_ID, CREATESEND_CLIENT_SECRET, 
// and CREATESEND_REDIRECT_URI environment variables for your registered
// OAuth application.

import static spark.Spark.*;
import spark.*;
import com.createsend.General;
import com.createsend.models.clients.ClientBasics;
import com.createsend.models.OAuthTokenDetails;
import com.createsend.util.AuthenticationDetails;
import com.createsend.util.OAuthAuthenticationDetails;
import com.createsend.util.exceptions.CreateSendException;

public class CreateSendOAuthTest {

    public static void main(String[] args) {

        setPort(Integer.parseInt(System.getenv("PORT")));

        get(new Route("/") {
            @Override
            public Object handle(Request req, Response res) {

                String authorizeUrl = General.getAuthorizeUrl(
                    Integer.parseInt(System.getenv("CREATESEND_CLIENT_ID")),
                    System.getenv("CREATESEND_REDIRECT_URI"),
                    "ViewReports,CreateCampaigns,SendCampaigns",
                    null);
                
                res.redirect(authorizeUrl);
                return "Redirected.";
            }
        });

        get(new Route("/exchange_token") {
            @Override
            public Object handle(Request req, Response res) {
                String code = req.queryParams("code");
                String response = "";

                try {
                    OAuthTokenDetails tokenDetails = General.exchangeToken(
                        Integer.parseInt(System.getenv("CREATESEND_CLIENT_ID")),
                        System.getenv("CREATESEND_CLIENT_SECRET"),
                        System.getenv("CREATESEND_REDIRECT_URI"),
                        code);
                    String accessToken = tokenDetails.access_token;
                    String refreshToken = tokenDetails.refresh_token;

                    response = "<pre>";
                    response += "Your user is successfully authenticated. Here are the details you need:<br/><br/>";
                    response += "access token: " + accessToken + "<br/>";
                    response += "refresh token: " + refreshToken + "<br/>";
                    response += "<br/><br/>";

                    AuthenticationDetails auth = new OAuthAuthenticationDetails(
                        accessToken, refreshToken);
                    General general = new General(auth);
                    ClientBasics[] clients = general.getClients();

                    response += "We've made an API call too. Here are your clients:<br/><br/>";
                    for (ClientBasics c : clients) {
                        response += c.Name + "<br/>";
                    }

                    response += "</pre>";
                } catch (CreateSendException ex) {
                    response = "Errors!<br/><br/>";
                    response += ex.toString();
                }

                return response;
            }
        });

    }
}