如何将相同的邮件发送给组中的每个收件人

Question

我正试图从我的jsf页面发送邮件。这是我的方法:

public String voegGroepToe()
{
    String resultaat = "overzichtGroepEnProject";
    if(project.getGroepen().size()<project.getMaxAantalGroepen())        
        project.voegGroepToe(groep);
    for(Student s : groep.getStudenten())
    {
    Properties props = new Properties();
    props.put("mail.smtp.host", "smtp.live.com");
    props.put("mail.smtp.port", "587");
    Session mailSession = Session.getDefaultInstance(props);
    Message simpleMessage = new MimeMessage(mailSession);
    InternetAddress fromAddress = null;
    InternetAddress toAddress = null;
    try {
        fromAddress = new InternetAddress(from);
        toAddress = new InternetAddress(s.getEmail());
    } catch (AddressException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    try {
        simpleMessage.setFrom(fromAddress);
        simpleMessage.setRecipient(RecipientType.TO, toAddress);
        simpleMessage.setSubject(subject);
        simpleMessage.setText(message);
        Transport.send(simpleMessage);          
    } catch (MessagingException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    }
    return resultaat;
}

resultaat是应用程序发送电子邮件后应该访问的JSF页面。Groep指的是一群学生。这封邮件应该发给小组的每个学生。from = "[e-mail]"

但是这是不工作的，它没有给出一个错误消息，它看起来像是卡在Transport.send…我做错了什么?

Answer 1

您希望在循环之前仅连接一次，然后在循环内使用Transport#sendMessage()发送每个消息，然后在循环之后关闭连接。第二个问题是，您似乎没有在任何地方传递用户名/密码。

你应该这样做:

String host = "smtp.live.com";
int port = 587;
String username = "[e-mail]";
String password = "yourpassword";
Properties props = new Properties();
props.put("mail.smtp.host", host);
props.put("mail.smtp.port", String.valueOf(port));
Session mailSession = Session.getDefaultInstance(props);
Transport transport = null;
try {
    transport = mailSession.getTransport("smtp");
    transport.connect(host, username, password);
    InternetAddress fromAddress = new InternetAddress(from);
    for (Student s : groep.getStudenten()) {
        InternetAddress[] toAddresses = { new InternetAddress(s.getEmail()) };
        Message simpleMessage = new MimeMessage(mailSession);
        simpleMessage.setFrom(fromAddress);
        simpleMessage.setRecipients(RecipientType.TO, toAddresses);
        simpleMessage.setSubject(subject);
        simpleMessage.setText(message);
        simpleMessage.setSentDate(new Date()); // Otherwise you end up in junk.
        simpleMessage.saveChanges(); // Transport#sendMessage() doesn't do it.
        transport.sendMessage(simpleMessage, toAddresses);
    }
} catch (MessagingException e) {
    // Handle it! Display a FacesMessage or something.
} finally {
    if (transport != null) try { transport.close(); } catch (MessagingException ignore) {}
}

(我不保证它会这样工作，我没有使用Live.com SMTP服务器的经验，也许你需要一个额外的Authenticator)

作为一个完全不同的选择，你也可以发送一个消息给[e-mail]与所有这些收件人作为密件。

参见:

JavaMail Fundamentals - Transport

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请注意，这个问题与JSF完全无关。在使用main()方法的普通Java类中这样做时，您将遇到完全相同的问题。