kindleclippings.quizlet.GetAccessToken.java Source code

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Here is the source code for kindleclippings.quizlet.GetAccessToken.java

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/**
 * Copyright (c) 2012, Howtobewebsmart.com, L.L.C. All rights reserved.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the Apache License, Version 2.0
 * as published by the Apache Software Foundation (the "License").
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 * You should have received a copy of the License along with this program.
 * If not, see <http://www.apache.org/licenses/LICENSE-2.0>.
 */
package kindleclippings.quizlet;

import java.awt.Desktop;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.URI;
import java.net.URISyntaxException;
import java.util.Arrays;
import java.util.UUID;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

import org.apache.http.HttpResponse;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONException;
import org.json.JSONObject;

import com.sun.net.httpserver.HttpExchange;
import com.sun.net.httpserver.HttpHandler;
import com.sun.net.httpserver.HttpServer;

class GetAccessToken {

    // see https://quizlet.com/api/2.0/docs/authorization_code_flow/
    private static final String clientId = "GET THIS FROM YOUR QUIZLET DEVELOPER DASHBOARD";

    // see https://quizlet.com/api/2.0/docs/authorization_code_flow/
    // looks like "Basic abcd......"
    private static final String authHeader = "GET THIS FROM YOUR QUIZLET DEVELOPER DASHBOARD";

    static JSONObject oauthDance() throws IOException, URISyntaxException, InterruptedException, JSONException {

        // start HTTP server, so when can get the authorization code
        InetSocketAddress addr = new InetSocketAddress(7777);
        HttpServer server = HttpServer.create(addr, 0);
        AuthCodeHandler handler = new AuthCodeHandler();
        server.createContext("/", handler);
        ExecutorService ex = Executors.newCachedThreadPool();
        server.setExecutor(ex);
        server.start();
        String authCode;
        try {
            Desktop.getDesktop()
                    .browse(new URI(new StringBuilder("https://quizlet.com/authorize/")
                            .append("?scope=read%20write_set").append("&client_id=" + clientId)
                            .append("&response_type=code").append("&state=" + handler.state).toString()));

            authCode = handler.result.take();
        } finally {
            server.stop(0);
            ex.shutdownNow();
        }

        if (authCode == null || authCode.length() == 0)
            return null;

        HttpPost post = new HttpPost("https://api.quizlet.com/oauth/token");
        post.setHeader("Authorization", authHeader);

        post.setEntity(
                new UrlEncodedFormEntity(Arrays.asList(new BasicNameValuePair("grant_type", "authorization_code"),
                        new BasicNameValuePair("code", authCode))));
        HttpResponse response = new DefaultHttpClient().execute(post);

        ByteArrayOutputStream buffer = new ByteArrayOutputStream(1000);
        response.getEntity().writeTo(buffer);
        return new JSONObject(new String(buffer.toByteArray(), "UTF-8"));
    }

    static class AuthCodeHandler implements HttpHandler {

        final String state = UUID.randomUUID().toString();

        final BlockingQueue<String> result = new ArrayBlockingQueue<String>(1);

        @Override
        public void handle(HttpExchange exchange) throws IOException {
            String requestMethod = exchange.getRequestMethod();
            OutputStream responseBody = exchange.getResponseBody();

            if (requestMethod.equalsIgnoreCase("GET")) {
                String uri = exchange.getRequestURI().toString();
                int code = uri.indexOf("&code=");
                if (code > -1 && uri.contains("state=" + state)) {
                    result.add(uri.substring(code + 6));
                    exchange.sendResponseHeaders(200, 0);
                    responseBody.write("ok.\n You can close this window now.".getBytes());
                } else {
                    exchange.sendResponseHeaders(400, 0);
                    responseBody.write(("invalid state " + uri).getBytes());
                    result.add("");
                }
            } else {
                exchange.sendResponseHeaders(500, 0);
                responseBody.write(("ignored unexpected request " + exchange.getRequestMethod() + " "
                        + exchange.getRequestURI()).getBytes());
            }
            responseBody.close();

        }

    }

}