olivierbellone/StripeSpark1OAuthApp.java

## callback.ftl
<!doctype html>
  <head>
    <title>Stripe OAuth Example</title>
  </head>
  <body>
    ${token}
  </body>
</html>

## index.ftl
<!doctype html>
  <head>
    <title>Stripe OAuth Example</title>
  </head>
  <body>
    <a href="/authorize">Connect with Stripe</a>
  </body>
</html>

## StripeSpark1OAuthApp.java
package com.stripe;

import java.lang.reflect.Type;
import java.util.HashMap;
import java.util.Map;
import java.net.URI;

import static spark.Spark.get;
import spark.ModelAndView;
import spark.Request;
import spark.Response;
import spark.Route;
import spark.template.freemarker.FreeMarkerRoute;

import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URIBuilder;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

import com.google.gson.GsonBuilder;
import com.google.gson.reflect.TypeToken;


public class StripeSpark1OAuthApp {
    public static final String CLIENT_ID = "YOUR_CLIENT_ID";
    public static final String API_KEY = "YOUR_SECRET_API_KEY";

    public static final String TOKEN_URI
        = "https://connect.stripe.com/oauth/token";
    public static final String AUTHORIZE_URI
        = "https://connect.stripe.com/oauth/authorize";

    public static void main(final String[] args) {
        get(new FreeMarkerRoute("/") {
            @Override
            public ModelAndView handle(final Request request,
                                       final Response response) {
                Map<String, Object> viewObjects
                    = new HashMap<String, Object>();

                return modelAndView(viewObjects, "index.ftl");
            }
        });

        get(new Route("/authorize") {
            @Override
            public Object handle(final Request request,
                                 final Response response) {
                try {
                    URI uri = new URIBuilder(AUTHORIZE_URI)
                            .setParameter("response_type", "code")
                            .setParameter("scope", "read_write")
                            .setParameter("client_id", CLIENT_ID)
                            .build();

                    // Redirect to Stripe /oauth/authorize endpoint
                    response.status(201);
                    response.redirect(uri.toString());
                } catch (Exception e) {
                    response.status(500);
                }
                return "";
            }
        });

        get(new FreeMarkerRoute("/oauth/callback") {
            @Override
            public ModelAndView handle(final Request request,
                                       final Response response) {
                Map<String, Object> viewObjects
                    = new HashMap<String, Object>();

                try {
                    CloseableHttpClient httpClient
                        = HttpClients.createDefault();
                    String code = request.queryParams("code");
                    URI uri = new URIBuilder(TOKEN_URI)
                            .setParameter("client_secret", API_KEY)
                            .setParameter("grant_type", "authorization_code")
                            .setParameter("client_id", CLIENT_ID)
                            .setParameter("code", code)
                            .build();

                    // Make /oauth/token endpoint POST request
                    HttpPost httpPost = new HttpPost(uri);
                    CloseableHttpResponse resp = httpClient.execute(httpPost);

                    // Grab access_token (use this as your user's API key)
                    String bodyAsString
                        = EntityUtils.toString(resp.getEntity());
                    Type t = new TypeToken<Map<String, String>>() { }.getType();
                    Map<String, String> map
                        = new GsonBuilder().create().fromJson(bodyAsString, t);
                    String token = map.get("access_token");

                    viewObjects.put("token", token);
                } catch (Exception e) {
                    response.status(500);
                }

                return modelAndView(viewObjects, "callback.ftl");
            }
        });
    }
}
	<!doctype html>
	<head>
	<title>Stripe OAuth Example</title>
	</head>
	<body>
	${token}
	</body>
	</html>
	package com.stripe;

	import java.lang.reflect.Type;
	import java.util.HashMap;
	import java.util.Map;
	import java.net.URI;

	import static spark.Spark.get;
	import spark.ModelAndView;
	import spark.Request;
	import spark.Response;
	import spark.Route;
	import spark.template.freemarker.FreeMarkerRoute;

	import org.apache.http.client.methods.CloseableHttpResponse;
	import org.apache.http.client.methods.HttpPost;
	import org.apache.http.client.utils.URIBuilder;
	import org.apache.http.impl.client.CloseableHttpClient;
	import org.apache.http.impl.client.HttpClients;
	import org.apache.http.util.EntityUtils;

	import com.google.gson.GsonBuilder;
	import com.google.gson.reflect.TypeToken;


	public class StripeSpark1OAuthApp {
	public static final String CLIENT_ID = "YOUR_CLIENT_ID";
	public static final String API_KEY = "YOUR_SECRET_API_KEY";

	public static final String TOKEN_URI
	= "https://connect.stripe.com/oauth/token";
	public static final String AUTHORIZE_URI
	= "https://connect.stripe.com/oauth/authorize";

	public static void main(final String[] args) {
	get(new FreeMarkerRoute("/") {
	@Override
	public ModelAndView handle(final Request request,
	final Response response) {
	Map<String, Object> viewObjects
	= new HashMap<String, Object>();

	return modelAndView(viewObjects, "index.ftl");
	}
	});

	get(new Route("/authorize") {
	@Override
	public Object handle(final Request request,
	final Response response) {
	try {
	URI uri = new URIBuilder(AUTHORIZE_URI)
	.setParameter("response_type", "code")
	.setParameter("scope", "read_write")
	.setParameter("client_id", CLIENT_ID)
	.build();

	// Redirect to Stripe /oauth/authorize endpoint
	response.status(201);
	response.redirect(uri.toString());
	} catch (Exception e) {
	response.status(500);
	}
	return "";
	}
	});

	get(new FreeMarkerRoute("/oauth/callback") {
	@Override
	public ModelAndView handle(final Request request,
	final Response response) {
	Map<String, Object> viewObjects
	= new HashMap<String, Object>();

	try {
	CloseableHttpClient httpClient
	= HttpClients.createDefault();
	String code = request.queryParams("code");
	URI uri = new URIBuilder(TOKEN_URI)
	.setParameter("client_secret", API_KEY)
	.setParameter("grant_type", "authorization_code")
	.setParameter("client_id", CLIENT_ID)
	.setParameter("code", code)
	.build();

	// Make /oauth/token endpoint POST request
	HttpPost httpPost = new HttpPost(uri);
	CloseableHttpResponse resp = httpClient.execute(httpPost);

	// Grab access_token (use this as your user's API key)
	String bodyAsString
	= EntityUtils.toString(resp.getEntity());
	Type t = new TypeToken<Map<String, String>>() { }.getType();
	Map<String, String> map
	= new GsonBuilder().create().fromJson(bodyAsString, t);
	String token = map.get("access_token");

	viewObjects.put("token", token);
	} catch (Exception e) {
	response.status(500);
	}

	return modelAndView(viewObjects, "callback.ftl");
	}
	});
	}
	}