edu.rit.honors.drive.servlets.util.Utils.java Source code

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Here is the source code for edu.rit.honors.drive.servlets.util.Utils.java

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/*
 * Copyright (c) 2013 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
 * in compliance with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */

package edu.rit.honors.drive.servlets.util;

import com.google.api.client.extensions.appengine.datastore.AppEngineDataStoreFactory;
import com.google.api.client.extensions.appengine.http.UrlFetchTransport;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.http.GenericUrl;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.Preconditions;
import com.google.api.client.util.store.DataStoreFactory;
import com.google.api.services.drive.DriveScopes;

import java.io.IOException;
import java.io.InputStreamReader;
import java.util.HashSet;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

public class Utils {

    /**
     * Global instance of the {@link DataStoreFactory}. The best practice is to
     * make it a single globally shared instance across your application.
     */
    private static final AppEngineDataStoreFactory DATA_STORE_FACTORY = AppEngineDataStoreFactory
            .getDefaultInstance();

    private static GoogleClientSecrets clientSecrets = null;
    public static final String MAIN_SERVLET_PATH = "/drive-sampleservlet";
    public static final String AUTH_CALLBACK_SERVLET_PATH = "/oauth2callback";
    public static final HttpTransport HTTP_TRANSPORT = new UrlFetchTransport();
    public static final JacksonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

    private static GoogleClientSecrets getClientSecrets() throws IOException {
        if (clientSecrets == null) {
            clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
                    new InputStreamReader(Utils.class.getResourceAsStream("/client_secrets.json")));
            Preconditions.checkArgument(
                    !clientSecrets.getDetails().getClientId().startsWith("Enter ")
                            && !clientSecrets.getDetails().getClientSecret().startsWith("Enter "),
                    "Download client_secrets.json file from "
                            + "https://code.google.com/apis/console/?api=drive#project:456052621 into "
                            + "src/main/resources/client_secrets.json");
        }
        return clientSecrets;
    }

    public static GoogleAuthorizationCodeFlow initializeFlow() throws IOException {
        // Ask for only the permissions you need. Asking for more permissions
        // will reduce the number of
        // users who finish the process for giving you access to their accounts.
        // It will also increase
        // the amount of effort you will have to spend explaining to users what
        // you are doing with their
        // data.
        // Here we are listing all of the available scopes. You should remove
        // scopes that you are not
        // actually using.
        Set<String> scopes = new HashSet<String>();
        scopes.add(DriveScopes.DRIVE);
        scopes.add(DriveScopes.DRIVE_APPDATA);
        scopes.add(DriveScopes.DRIVE_APPS_READONLY);
        scopes.add(DriveScopes.DRIVE_FILE);
        scopes.add(DriveScopes.DRIVE_METADATA_READONLY);
        scopes.add(DriveScopes.DRIVE_READONLY);
        scopes.add(DriveScopes.DRIVE_SCRIPTS);

        return new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY, getClientSecrets(), scopes)
                .setDataStoreFactory(DATA_STORE_FACTORY).setAccessType("offline").build();
    }

    public static String getRedirectUri(HttpServletRequest req) {
        GenericUrl requestUrl = new GenericUrl(req.getRequestURL().toString());
        requestUrl.setRawPath(AUTH_CALLBACK_SERVLET_PATH);
        return requestUrl.build();
    }
}