import com.google.api.client.googleapis.extensions.java6.auth.oauth2.GooglePromptReceiver; //导入依赖的package包/类
/**
 * Authorizes the installed application to access user's protected data.
 */
public static Credential authorize() throws IOException {
    // Load client secrets.
    final byte[] bytes = Files.toByteArray(new File(clientSecretFile));
    final GoogleClientSecrets clientSecrets = GoogleClientSecrets
        .load(JSON_FACTORY, new InputStreamReader(new ByteArrayInputStream(bytes)));
    if (clientSecrets.getDetails().getClientId() == null
        || clientSecrets.getDetails().getClientSecret() == null) {
        throw new IllegalStateException("client_secrets not well formed.");
    }


    // Set up authorization code flow.
    // 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.
    final Set<String> scopes = new HashSet<String>();
    scopes.add(StorageScopes.DEVSTORAGE_FULL_CONTROL);
    scopes.add(StorageScopes.DEVSTORAGE_READ_ONLY);
    scopes.add(StorageScopes.DEVSTORAGE_READ_WRITE);

    final GoogleAuthorizationCodeFlow flow =
        new GoogleAuthorizationCodeFlow.Builder(httpTransport, JSON_FACTORY, clientSecrets,
            scopes).setDataStoreFactory(dataStoreFactory).build();
    // Authorize.
    final VerificationCodeReceiver receiver =
        AUTH_LOCAL_WEBSERVER ? new LocalServerReceiver() : new GooglePromptReceiver();
    return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}
 

import com.google.api.client.googleapis.extensions.java6.auth.oauth2.GooglePromptReceiver; //导入依赖的package包/类
/**
 * Initialized OAuth2 credential for the "installed application" flow; where the credential
 * typically represents an actual end user (instead of a service account), and is stored as a
 * refresh token in a local FileCredentialStore.
 *
 * @param clientId OAuth2 client ID identifying the 'installed app'
 * @param clientSecret OAuth2 client secret
 * @param filePath full path to a ".json" file for storing the credential
 * @param scopes list of well-formed scopes desired in the credential
 * @param transport The HttpTransport used for authorization
 * @return credential with desired scopes, possibly obtained from loading {@code filePath}.
 * @throws IOException on IO error
 */
public Credential getCredentialFromFileCredentialStoreForInstalledApp(
    String clientId,
    String clientSecret,
    String filePath,
    List<String> scopes,
    HttpTransport transport)
    throws IOException, GeneralSecurityException {
  LOG.debug("getCredentialFromFileCredentialStoreForInstalledApp({}, {}, {}, {})",
      clientId, clientSecret, filePath, scopes);
  Preconditions.checkArgument(!Strings.isNullOrEmpty(clientId),
      "clientId must not be null or empty");
  Preconditions.checkArgument(!Strings.isNullOrEmpty(clientSecret),
      "clientSecret must not be null or empty");
  Preconditions.checkArgument(!Strings.isNullOrEmpty(filePath),
      "filePath must not be null or empty");
  Preconditions.checkArgument(scopes != null,
      "scopes must not be null or empty");

  // Initialize client secrets.
  GoogleClientSecrets.Details details = new GoogleClientSecrets.Details();
  details.setClientId(clientId);
  details.setClientSecret(clientSecret);
  GoogleClientSecrets clientSecrets = new GoogleClientSecrets();
  clientSecrets.setInstalled(details);

  // Set up file credential store.
  FileCredentialStore credentialStore =
      new FileCredentialStore(new File(filePath), JSON_FACTORY);

  // Set up authorization code flow.
  GoogleAuthorizationCodeFlow flow =
      new GoogleAuthorizationCodeFlow.Builder(transport, JSON_FACTORY, clientSecrets, scopes)
          .setCredentialStore(credentialStore)
          .setRequestInitializer(new CredentialHttpRetryInitializer())
          .build();

  // Authorize access.
  return new AuthorizationCodeInstalledApp(flow, new GooglePromptReceiver()).authorize("user");
}
 

import com.google.api.client.googleapis.extensions.java6.auth.oauth2.GooglePromptReceiver; //导入依赖的package包/类
/** Authorizes the installed application to access user's protected data. */
private static Credential authorize() throws Exception {
  // Load client secrets.
  GoogleClientSecrets clientSecrets = null;
  try {
    clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,
        new InputStreamReader(StorageSample.class.getResourceAsStream(String.format("/%s",CLIENT_SECRET_FILENAME))));
    if (clientSecrets.getDetails().getClientId() == null ||
        clientSecrets.getDetails().getClientSecret() == null) {
        throw new Exception("client_secrets not well formed.");
    }
  } catch (Exception e) {
    System.out.println("Problem loading client_secrets.json file. Make sure it exists, you are " + 
                      "loading it with the right path, and a client ID and client secret are " +
                      "defined in it.\n" + e.getMessage());
    System.exit(1);
  }

  // Set up authorization code flow.
  // 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(StorageScopes.DEVSTORAGE_FULL_CONTROL);
  scopes.add(StorageScopes.DEVSTORAGE_READ_ONLY);
  scopes.add(StorageScopes.DEVSTORAGE_READ_WRITE);

  GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
      httpTransport, JSON_FACTORY, clientSecrets, scopes)
      .setDataStoreFactory(dataStoreFactory)
      .build();
  // Authorize.
  VerificationCodeReceiver receiver = 
      AUTH_LOCAL_WEBSERVER ? new LocalServerReceiver() : new GooglePromptReceiver();
  return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");    
}
 

import com.google.api.client.googleapis.extensions.java6.auth.oauth2.GooglePromptReceiver; //导入依赖的package包/类
/**
 * Authorizes the installed application to access user's protected data.
 */
private Credential authorizeUser(GoogleClientSecrets clientSecrets) throws Exception
{
    // set up file credential store
    //CredentialStore credentialStore = new MemoryCredentialStore();
    CredentialStore credentialStore = new FileCredentialStore(new java.io.File(CREDENTIAL_FILE), JSON_FACTORY);

    // set up authorization code flow
    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES).setCredentialStore(credentialStore).build();

    // authorize
    VerificationCodeReceiver receiver = new GooglePromptReceiver();
    return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}
 

import com.google.api.client.googleapis.extensions.java6.auth.oauth2.GooglePromptReceiver; //导入依赖的package包/类
/**
 * Authorizes the installed application to access user's protected data.
 */
private static Credential authorizeUser(GoogleClientSecrets clientSecrets) throws Exception
{
    // set up file credential store
    //CredentialStore credentialStore = new MemoryCredentialStore();
    CredentialStore credentialStore = new FileCredentialStore(new java.io.File(CREDENTIAL_FILE), JSON_FACTORY);

    // set up authorization code flow
    GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(
            HTTP_TRANSPORT, JSON_FACTORY, clientSecrets, SCOPES).setCredentialStore(credentialStore).build();

    // authorize
    VerificationCodeReceiver receiver = new GooglePromptReceiver();
    return new AuthorizationCodeInstalledApp(flow, receiver).authorize("user");
}