在java中发送电子邮件时引发异常

Question

我是Java初学者，我想用Java发送电子邮件。为此，我使用这段代码发送电子邮件，但这段代码引发了一个异常。我已经验证了我的用户名和密码，它们绝对没有问题，所以请告诉我是否有其他方法用Java发送电子邮件？

这是异常的堆栈跟踪：

javax.mail.AuthenticationFailedException: 534-5.7.14 <https://accounts.google.com/ContinueSignIn?sarp=1&scc=1&plt=AKgnsbsNX
534-5.7.14 No6jJbDc4l7fZ_WLdBD0sNHIIp_nLvplRMm0bYFBnZBF_XOyVvNSdd1FenDZJPwBTFQyRH
534-5.7.14 lriPK3myMm-dXkW3zK0-6XpO7BzI8hfRcByG1k7YiVzXlddTvs7QhjtgCWNcrzMBuPhoof
534-5.7.14 GjME2TgYzXJVHz5MV98nRnr_kq-kP7RmgOtX3IQHLwM5E8QGBC9-2THVQr_Ch_U0-1nZsc
534-5.7.14 yoPuNEw> Please log in via your web browser and then try again.
534-5.7.14 Learn more at
534 5.7.14 https://support.google.com/mail/bin/answer.py?answer=78754 wr6sm26888533wjc.24 - gsmtp

    at com.sun.mail.smtp.SMTPTransport$Authenticator.authenticate(SMTPTransport.java:892)
    at com.sun.mail.smtp.SMTPTransport.authenticate(SMTPTransport.java:814)
    at com.sun.mail.smtp.SMTPTransport.protocolConnect(SMTPTransport.java:728)
    at javax.mail.Service.connect(Service.java:364)
    at javax.mail.Service.connect(Service.java:245)
    at SendEmail.sendFromGMail(SendEmail.java:50)
    at SendEmail.main(SendEmail.java:18)
sent

这是我的代码

import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;

public class SendEmail {

    private static String USER_NAME = "me";
    private static String PASSWORD = "xyz";
    private static String RECIPIENT = "[e-mail]";

    public static void main(String[] args) {
        String from = USER_NAME;
        String pass = PASSWORD;
        String[] to = { RECIPIENT };
        String subject = "Java send mail example";
        String body = "Welcome to JavaMail!";

        sendFromGMail(from, pass, to, subject, body);
        System.out.println("sent");
    }

    private static void sendFromGMail(String from, String pass, String[] to, String subject, String body) {
        Properties props = System.getProperties();
        String host = "smtp.gmail.com";
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.host", host);
        props.put("mail.smtp.user", from);
        props.put("mail.smtp.password", pass);
        props.put("mail.smtp.port", "587");
        props.put("mail.smtp.auth", "true");

        Session session = Session.getDefaultInstance(props);
        MimeMessage message = new MimeMessage(session);

        try {
            message.setFrom(new InternetAddress(from));
            InternetAddress[] toAddress = new InternetAddress[to.length];

            for( int i = 0; i < to.length; i++ ) {
                toAddress[i] = new InternetAddress(to[i]);
            }

            for( int i = 0; i < toAddress.length; i++) {
                message.addRecipient(Message.RecipientType.TO, toAddress[i]);
            }

            message.setSubject(subject);
            message.setText(body);
            Transport transport = session.getTransport("smtp");
            transport.connect(host, from, pass);
            transport.sendMessage(message, message.getAllRecipients());
            transport.close();
        }
        catch (AddressException ae) {
            ae.printStackTrace();
        }
        catch (MessagingException me) {
            me.printStackTrace();
        }
    }
}

Answer 1

原因：谷歌屏蔽了来自未知位置的访问（应用程序正在生产）

解决方案：去http://www.google.com/accounts/DisplayUnlockCaptcha然后单击“继续”（这将授予注册新应用的10分钟访问权限）。在这之后，我的制作应用程序开始发送电子邮件；）

Answer 2

尝试通过添加以下属性来启用SSL：

props.put("mail.smtp.socketFactory.port", "587");
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

也可以试着像下面这样提示会话：

Session session = Session.getDefaultInstance(props,
    new javax.mail.Authenticator() {
        protected PasswordAuthentication getPasswordAuthentication() {
            return new PasswordAuthentication(username, password);
    }
});

如果启用了两步验证，则需要创建应用程序密码并使用该密码进行身份验证。