io.konig.maven.google.download.GoogleDownloadClient.java Source code

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Here is the source code for io.konig.maven.google.download.GoogleDownloadClient.java

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package io.konig.maven.google.download;

/*
 * #%L
 * Konig Google Download Maven Plugin
 * %%
 * Copyright (C) 2015 - 2017 Gregory McFall
 * %%
 * 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.
 * #L%
 */

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.List;

import com.google.api.client.auth.oauth2.Credential;
import com.google.api.client.extensions.java6.auth.oauth2.AuthorizationCodeInstalledApp;
import com.google.api.client.extensions.jetty.auth.oauth2.LocalServerReceiver;
import com.google.api.client.googleapis.auth.oauth2.GoogleAuthorizationCodeFlow;
import com.google.api.client.googleapis.auth.oauth2.GoogleClientSecrets;
import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.http.HttpTransport;
import com.google.api.client.json.JsonFactory;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.client.util.store.FileDataStoreFactory;
import com.google.api.services.drive.Drive;
import com.google.api.services.drive.DriveScopes;

public class GoogleDownloadClient {
    /** Application name. */
    private static final String APPLICATION_NAME = "Drive API Java Quickstart";

    /** Directory to store user credentials for this application. */
    private static final java.io.File DATA_STORE_DIR = new java.io.File(System.getProperty("user.home"),
            ".credentials/io.konig.maven.google.download");

    /** Global instance of the {@link FileDataStoreFactory}. */
    private static FileDataStoreFactory DATA_STORE_FACTORY;

    /** Global instance of the JSON factory. */
    private static final JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance();

    /** Global instance of the HTTP transport. */
    private static HttpTransport HTTP_TRANSPORT;

    /** Global instance of the scopes required by this quickstart.
     *
     * If modifying these scopes, delete your previously saved credentials
     * at ~/.credentials/drive-java-quickstart
     */
    private static final List<String> SCOPES = Arrays.asList(DriveScopes.DRIVE_READONLY);

    private static final String MS_EXCEL_MEDIA_TYPE = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";

    static {
        try {
            HTTP_TRANSPORT = GoogleNetHttpTransport.newTrustedTransport();
            DATA_STORE_FACTORY = new FileDataStoreFactory(DATA_STORE_DIR);
        } catch (Throwable t) {
            t.printStackTrace();
            System.exit(1);
        }
    }

    /**
     * Creates an authorized Credential object.
     * @return an authorized Credential object.
     * @throws IOException
     */
    private Credential authorize() throws IOException {
        // Load client secrets.
        InputStream in = GoogleDownloadClient.class.getResourceAsStream("/GoogleDownloadClient/clientInfo.json");
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY, new InputStreamReader(in));

        // Build flow and trigger user authorization request.
        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(HTTP_TRANSPORT, JSON_FACTORY,
                clientSecrets, SCOPES).setDataStoreFactory(DATA_STORE_FACTORY).setAccessType("offline").build();
        Credential credential = new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver())
                .authorize("user");
        System.out.println("Credentials saved to " + DATA_STORE_DIR.getAbsolutePath());
        return credential;
    }

    /**
     * Build and return an authorized Drive client service.
     * @return an authorized Drive client service
     * @throws IOException
     */
    private Drive getDriveService() throws IOException {
        Credential credential = authorize();
        return new Drive.Builder(HTTP_TRANSPORT, JSON_FACTORY, credential).setApplicationName(APPLICATION_NAME)
                .build();
    }

    public void execute(String documentId, File saveAs) throws DownloadException {

        try {
            saveAs.getParentFile().mkdirs();
            OutputStream output = new FileOutputStream(saveAs);
            try {
                Drive service = getDriveService();
                service.files().export(documentId, MS_EXCEL_MEDIA_TYPE).executeMediaAndDownloadTo(output);
            } catch (IOException e) {
                throw new DownloadException("Failed to download spreadsheet: " + documentId, e);
            } finally {
                close(output);
            }

        } catch (IOException e) {
            throw new DownloadException("Failed to create output stream: " + saveAs.getAbsolutePath(), e);
        }

    }

    private void close(OutputStream output) {
        try {
            output.close();
        } catch (IOException e) {
            // Silently ignore
        }

    }

}