Java连接到gmail并发送文件

Question

代码：

public static void sendMailAttachments(String mensaje, String cartera, String asunto, String file) throws AddressException, MessagingException, IOException{
    //Get user, pass, to
    getDatosCorreo();
    Properties props = new Properties();
    props.put("mail.smtp.port", "465");
    props.put("mail.smtp.auth", "true");
    props.put("mail.smtp.ssl.trust", "smtp.gmail.com");
    props.put("mail.smtp.starttls.enable", "true");
    Session session = Session.getDefaultInstance(props,
            new javax.mail.Authenticator() {
                protected PasswordAuthentication getPasswordAuthentication() {
                    return new PasswordAuthentication(user,pass);
                }
            });
    try {
        Message message = new MimeMessage(session);
        message.setFrom(new InternetAddress(user));
        message.addRecipients(Message.RecipientType.TO, InternetAddress.parse(to.get(0)));
        message.setSubject("Email Subject - Asunto del correo electronico");
        BodyPart messageBodyPart = new MimeBodyPart();
        messageBodyPart.setText("Email text Body - Texto o cuerpo del correo electronico");
        Multipart multipart = new MimeMultipart();
        multipart = addAttachment(multipart, file);
        //Setting email text message
        multipart.addBodyPart(messageBodyPart);
        //set the attachments to the email
        message.setContent(multipart);
        Transport.send(message);
        System.out.println("Correo enviado");
    } catch (MessagingException e) {
        throw new RuntimeException(e);
    }
}

例外：

GRAVE：无法将 RuntimeException 映射到响应， 重新抛出到 HTTP 容器 java.lang.RuntimeException： javax.mail.MessagingException： 无法连接到 SMTP 主机： 本地主机，端口：465，响应：-1 at 实用。邮件发送邮件附件(邮件.java：128(

如何连接和发送文件？

此代码连接到 Gmail 并发送邮件。

我需要添加一个文件才能发送。

getDatosCorreo();
// TODO Auto-generated method stub
// Step1
System.out.println("n 1st ===> setup Mail Server Properties..");
mailServerProperties = System.getProperties();
mailServerProperties.put("mail.smtp.port", "587");
mailServerProperties.put("mail.smtp.auth", "true");
mailServerProperties.put("mail.smtp.ssl.trust", "smtp.gmail.com");
mailServerProperties.put("mail.smtp.starttls.enable", "true");
System.out.println("Mail Server Properties have been setup successfully..");
// Step2
System.out.println("nn 2nd ===> get Mail Session..");
getMailSession = Session.getDefaultInstance(mailServerProperties, null);
generateMailMessage = new MimeMessage(getMailSession);
for(int i = 0; i < to.size(); i++) {
    if(i == 0) {
        generateMailMessage.addRecipient(Message.RecipientType.TO, new InternetAddress(to.get(i)));
    }else {
        generateMailMessage.addRecipient(Message.RecipientType.CC, new InternetAddress(to.get(i)));
    }
}
generateMailMessage.setSubject(asunto+cartera);
generateMailMessage.setContent(mensaje, "text/html");
System.out.println("Mail Session has been created successfully..");
// Step3
System.out.println("nn 3rd ===> Get Session and Send mail");
Transport transport = getMailSession.getTransport("smtp");
// Enter your correct gmail UserID and Password
// if you have 2FA enabled then provide App Specific Password
transport.connect("smtp.gmail.com", user, pass);
transport.sendMessage(generateMailMessage, generateMailMessage.getAllRecipients());
transport.close();
System.out.println("nn 4rd ===> Send email correctly");

Answer 1

使用带有 SSL 的电子邮件服务时，以下设置对我有用：

props.put("mail.smtp.host", "smtp.gmail.com");
props.put("mail.smtp.socketFactory.port", "465");
props.put("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
props.put("mail.smtp.auth", "true");
props.put("mail.smtp.starttls.enable", "true");
props.put("mail.smtp.port", "465");

我不知道您是否需要设置 mail.smtp.ssl.trust 属性。 这个SO答案不需要它，我也没有让它与我的特定SSL电子邮件服务一起工作。