无法发送电子邮件在AppEngine教程

Question

我只是简单地按照教程中概述：https://cloud.google.com/solutions/mobile/firebase-app-engine-android-studio，部分添加后端模块。

servlet代码我已经是：

import com.firebase.client.DataSnapshot; 
import com.firebase.client.Firebase; 
import com.firebase.client.FirebaseError; 
import com.firebase.client.ValueEventListener; 

import java.io.IOException; 
import java.io.UnsupportedEncodingException; 
import java.util.Properties; 
import java.util.logging.Logger; 

import javax.mail.Message; 
import javax.mail.MessagingException; 
import javax.mail.Session; 
import javax.mail.Transport; 
import javax.mail.internet.InternetAddress; 
import javax.mail.internet.MimeMessage; 
import javax.servlet.http.HttpServlet; 
import javax.servlet.http.HttpServletRequest; 
import javax.servlet.http.HttpServletResponse; 

public class MyServlet extends HttpServlet { 
    static Logger Log = Logger.getLogger("com.example.username.myapplication.backend.MyServlet"); 

    @Override 
    public void doGet(HttpServletRequest req, HttpServletResponse resp) 
      throws IOException { 
     Log.info("Got cron message, constructing email."); 

     //Create a new Firebase instance and subscribe on child events. 
     Firebase firebase = new Firebase("[firebase-DB]"); 
     firebase.addListenerForSingleValueEvent(new ValueEventListener() { 
      @Override 
      public void onDataChange(DataSnapshot dataSnapshot) { 
       // Build the email message contents using every field from Firebase. 
       final StringBuilder newItemMessage = new StringBuilder(); 
       newItemMessage.append("Hello main user"); 


       //Now Send the email 
       Properties props = new Properties(); 
       Session session = Session.getDefaultInstance(props, null); 
      try { 
       Message msg = new MimeMessage(session); 
       //Make sure you substitute your project-id in the email From field 
       msg.setFrom(new InternetAddress("anything@firebasebackendserver.appspotmail.com", 
         "Todo Nagger")); 
       msg.addRecipient(Message.RecipientType.TO, 
         new InternetAddress("myEmail@gmail.com", "Recipient")); 
       msg.setSubject("Good Morning!"); 
       msg.setText(newItemMessage.toString()); 
       Transport.send(msg); 
      } catch (MessagingException | UnsupportedEncodingException e) { 
       Log.warning(e.getMessage()); 
      } 
      } 

      public void onCancelled(FirebaseError firebaseError) { 
      } 
     }); 
    } 

} 

而且cron.xml文件：

<?xml version="1.0" encoding="UTF-8"?> 
<cronentries> 
    <cron> 
     <url>/hello</url> 
     <description>Send me an email of outstanding items in the morning</description> 
     <schedule>every 1 minutes</schedule> 
    </cron> 
</cronentries> 

完成了在火力地堡后，AppEngine上仪表板并注册一个请求已经发生，但是，电子邮件永远不会发送，所有我在日志中看到的是错误：

Caused by: com.google.apphosting.api.ApiProxy$FeatureNotEnabledException: The Socket API will be enabled for this application once billing has been enabled in the admin console. 

尽管我已经为此应用启用了结算功能。

在开始使用计费之前是否有某种宽限期？

代码布局有什么问题？

Answer 1

我怀疑你是从一个不允许的发件人发送。下面是来自docs的摘录：

为了安全起见，邮件的发件人地址必须是下列之一：

• 谁是目前在
登录的用户的Gmail或谷歌应用服务帐户
• 形式的任何电子邮件地址anything@appname.appspotmail.com或anything@appalias.appspotmail.com
• 在云平台上控制台中列出的任何电子邮件地址下Email API Authorized Senders

如果是这种情况，您将在logs中看到一个错误。