通過Gmail API發送電子郵件Google App Engine

Question

試圖使用Gmail API將電子郵件發送到App Engine。以前，我在Credentials頁面中創建了一個Service帳號密鑰，它會生成一個位於setServiceAccountPrivateKeyFromP12File參數中的.P12文件。它有一個ID帳號加入帳號somename@appspot.gserviceaccount.com到服務帳號頁面。代碼：

/* Application name. */ 
    private static final String APPLICATION_NAME = "appnamefromappengine"; 

    String emailAddress = "somename@appspot.gserviceaccount.com"; 
    JsonFactory JSON_FACTORY = JacksonFactory.getDefaultInstance(); 
    try { 
     HttpTransport httpTransport = GoogleNetHttpTransport.newTrustedTransport(); 

     Set<String> scopes = new HashSet<String>(); 
     scopes.add(GmailScopes.GMAIL_SEND); 
     scopes.add(GmailScopes.GMAIL_COMPOSE); 
     scopes.add(GmailScopes.MAIL_GOOGLE_COM); 
     scopes.add("https://www.googleapis.com/auth/admin.directory.user"); 

     GoogleCredential credential = new GoogleCredential.Builder() 
      .setTransport(httpTransport) 
      .setJsonFactory(JSON_FACTORY) 
      .setServiceAccountId(emailAddress) 
      .setServiceAccountPrivateKeyFromP12File(new File("/home/myuser/Test/src/main/webapp/resources/**somename**cd30e7118ad5.p12")) 
      .setServiceAccountScopes(scopes) 
      .setServiceAccountUser("somename@appspot.gserviceaccount.com") 
      .build(); 
     Gmail gmail = new Gmail 
      .Builder(httpTransport, JSON_FACTORY, credential) 
      .setApplicationName(APPLICATION_NAME) 
      .build(); 

     Properties props = new Properties(); 
     Session session = Session.getDefaultInstance(props, null); 
     MimeMessage message = new MimeMessage(session); 
     message.setFrom(new InternetAddress("someemail@gmail.com")); 
     message.addRecipient(javax.mail.Message.RecipientType.TO, new InternetAddress("recipient@gmail.com")); 
     message.setSubject("Test Mail"); 
     message.setText("Test Mail"); 

     Message msg = createMessageWithEmail(message); //createMessageWithEmail function from Gmail API 
     msg = gmail.users().messages().send(emailAddress, msg).execute(); 

     System.out.println("Mail was sent. Message id: " + msg.getId()); 

    } catch (GeneralSecurityException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } catch (MessagingException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 

它返回我這個錯誤：

com.google.api.client.googleapis.json.GoogleJsonResponseException: 400 Bad Request { "code" : 400,
"errors" : [ { "domain" : "global", "message" : "Bad Request", "reason" : "failedPrecondition" } ],
"message" : "Bad Request" }

我不知道我設置錯了這裏的代碼或到谷歌雲控制檯哪個參數。我還能嘗試什麼？

Answer 1

問題是我沒有將委派域範圍的權限配置到服務帳戶到管理控制檯中。

1. Go to your Google Apps domain’s Admin console.

2. Select Security from the list of controls. If you don't see Security listed, select More controls from the gray bar at the bottom of the page, then select Security from the list of controls. If you can't see the controls, make sure you're signed in as an administrator for the domain.

3. Select Show more and then Advanced settings from the list of options.

4. Select Manage API client access in the Authentication section.

5. In the Client Name field enter the service account's Client ID. You can find your service account's client ID in the Service accounts section of the Developers Console's Permissions page.

6. In the One or More API Scopes field enter the list of scopes that your application should be granted access to. For example, if your application needs domain-wide access to the Google Drive API and the Google Calendar API, enter: https://www.googleapis.com/auth/drive , https://www.googleapis.com/auth/calendar .

7. Click Authorize.

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