使用Java从Google Storage下载文件

Question

使用Java从Google Storage下载文件

Mez*_*Mez 11 java google-api google-authentication google-api-java-client google-cloud-storage

我已成功自动完成将Google Big Query中的数据移至Google存储空间的流程.现在,我还需要以自动方式将数据从Google Storage下载到我的环境中.

我正在尝试执行正常的HTTP请求,但之前已授权.所以我的HTTP请求是

    HttpRequestFactory requestFactory = HTTP_TRANSPORT.createRequestFactory(authorize());
    GenericUrl url = new GenericUrl(uri);
    HttpRequest request = requestFactory.buildGetRequest(url);
    HttpResponse response = request.execute();
    String content = response.parseAsString();

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我的授权码是

/** Authorizes the installed application to access user's protected data. */
    private static Credential authorize() throws Exception
    {
        HttpTransport httpTransport = new NetHttpTransport();
        JsonFactory jsonFactory = new JacksonFactory();

        // load client secrets
        GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
                new InputStreamReader(BigQueryConsumer.class.getResourceAsStream("/secret.json")));

        // This creates the credentials datastore at ~/.oauth-credentials/${credentialDatastore}
        FileDataStoreFactory fileDataStoreFactory = new FileDataStoreFactory(new File(System.getProperty("user.home") + "/" + CREDENTIALS_DIRECTORY));

        // set up authorization code flow
        GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
                httpTransport, JSON_FACTORY, clientSecrets,
                SCOPES).setDataStoreFactory(fileDataStoreFactory)
                .build();
        // authorize
        return new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");
    }

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以下常量的位置

CREDENTIALS_DIRECTORY:".aeuth-credentials"
JSON_FACTORY:JacksonFactory.getDefaultInstance()
范围:只有" https://www.googleapis.com/auth/devstorage.full_control " 的字符串列表
HTTP_TRANSPORT:新的NetHttpTransport()

在身份验证/授权过程中我错过了什么？我正进入(状态

    Exception in thread "main" com.google.api.client.http.HttpResponseException: 401 Unauthorized
<HTML>
<HEAD>
<TITLE>Unauthorized</TITLE>
</HEAD>
<BODY BGCOLOR="#FFFFFF" TEXT="#000000">
<H1>Unauthorized</H1>
<H2>Error 401</H2>
</BODY>
</HTML>

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Answer 1

Mez*_*Mez 5

寻找答案的其他人.要使用应用程序默认凭据,您需要遵循以下几个步骤...您可以按照以下步骤操作,或查看此链接.

首先要做的事情是:安装谷歌云存储SDK
确保您可以从SDK运行命令.如果您没有安装python,则需要安装python 2.7或更高版本,以及pyopenssl ...
您需要通过运行gcloud auth activate-service-account [服务帐户电子邮件] --key-fil e [.p12文件](在方括号中编辑值)从SDK中进行身份验证.当您运行此操作时,您应该收到一条消息,告诉您已激活您的服务帐户
您需要通过将GOOGLE_APPLICATION_CREDENTIALS设置为秘密的JSON路径(从开发人员控制台创建的服务帐户下载的路径)CLOUDSDK_PYTHON_SITEPACKAGES设置为1来设置项目环境变量,并设置项目

配置系统变量的命令......

set GOOGLE_APPLICATION_CREDENTIALS "secret.json path"
set CLOUDSDK_PYTHON_SITEPACKAGES 1
gcloud config set project "your project name"

在您进行身份验证并自行授权后,您可以开始使用应用程序默认凭据,前提是您已正确设置环境.

成功设置环境后,您可以通过身份验证并获取默认凭据

        GoogleCredential credential = GoogleCredential.getApplicationDefault();

        if (credential.createScopedRequired()) {
            credential = credential.createScoped(StorageScopes.all());
        }

        HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport();
        storageService = new Storage.Builder(httpTransport, jsonFactory, credential)
                .setApplicationName(applicationName).build();

并使用HTTP GET从您的谷歌存储桶中获取对象,例如以下内容

// Set up and execute a Google Cloud Storage request.
                String uri = "https://storage.googleapis.com/" + URLEncoder.encode("[your bucket name here]", "UTF-8") + "/" + googleStorageFileName + "/" + fileName;

                httpTransport = GoogleNetHttpTransport.newTrustedTransport();
                HttpRequestFactory requestFactory = httpTransport.createRequestFactory(
                        credential);
                GenericUrl url = new GenericUrl(uri);

                HttpRequest request = requestFactory.buildGetRequest(url);
                HttpResponse response = request.execute();
                String content = response.parseAsString();
                BufferedWriter writer = new BufferedWriter( new FileWriter( pathToSave + googleStorageFileName));
                writer.write( content);

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