AppEngine 教程中无法发送电子邮件

Question

我只是按照以下教程进行操作：https://cloud.google.com/solutions/mobile/firebase-app-engine-android-studio，添加后端模块部分。

我的 Servlet 代码是：

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) {
            }
        });
    }

}

cron.xml 文件为：

<?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>

在 Firebase 中完成后，AppEngine 仪表板确实记录了请求已发生，但是，电子邮件从未发送，我在日志中看到的只是错误：

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.

即使我已经为此应用启用了计费功能。

在启用计费后是否有某种宽限期才能真正开始使用它...？

代码布局有什么问题？

Answer 1

我怀疑您是从不允许的发件人那里发送的。这是docs的摘录：

出于安全考虑，邮件的发件人地址必须是以下之一：

• 当前登录用户的 Gmail 或 Google Apps 帐户
• 任何形式为anything@appname.appspotmail.com 或anything@appalias.appspotmail.com 的电子邮件地址
• Cloud Platform Console 中Email API Authorized Senders 下列出的任何电子邮件地址

如果是这种情况，您将在logs 中看到错误。