使用OAuth在Android中发送电子邮件而无需用户交互

Question

I am getting this error while trying to connect to smtp

javax.mail.MessagingException: 334 eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ==

Here is my code

public class GMailOauthSender
{
    private Session session;

    public SMTPTransport connectToSmtp(String host, int port, String userEmail, String oauthToken, boolean debug) throws Exception {

        Properties props = new Properties();
        props.put("mail.smtp.starttls.enable", "true");
        props.put("mail.smtp.starttls.required", "true");
        props.put("mail.smtp.sasl.enable", "false");
        session = Session.getInstance(props);
        session.setDebug(debug);

        final URLName unusedUrlName = null;
        SMTPTransport transport = new SMTPTransport(session, unusedUrlName);
        // If the password is non-null, SMTP tries to do AUTH LOGIN.
        final String emptyPassword = null;
        transport.connect(host, port, userEmail, emptyPassword);

        byte[] response = String.format("user=%s\1auth=Bearer %s\1\1", userEmail, oauthToken).getBytes();
        response = BASE64EncoderStream.encode(response);

        transport.issueCommand("AUTH XOAUTH2 " + new String(response), 235);

        return transport;
    }

    public synchronized void sendMail(String subject, String body, String user, String oauthToken, String recipients) {
        try {
            SMTPTransport smtpTransport = connectToSmtp("smtp.gmail.com",587,user,oauthToken,true);

            MimeMessage message = new MimeMessage(session);
            DataHandler handler = new DataHandler(new ByteArrayDataSource(body.getBytes(), "text/plain"));   
            message.setSender(new InternetAddress(user));   
            message.setSubject(subject);   
            message.setDataHandler(handler);   

            if (recipients.indexOf(',') > 0)   
                message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients));   
            else  
                message.setRecipient(Message.RecipientType.TO, new InternetAddress(recipients));   

            smtpTransport.sendMessage(message, message.getAllRecipients());   
        } catch (Exception e) {
            Log.d("test", e.getMessage());
        }
    }
}

I have got this code from some where in stack overflow. any help??

Answer 1

The error you are receiving

eyJzdGF0dXMiOiI0MDAiLCJzY2hlbWVzIjoiQmVhcmVyIiwic2NvcGUiOiJodHRwczovL21haWwuZ29vZ2xlLmNvbS8ifQ==

decodes to the following using a Base64 Decoder

{"status":"400","schemes":"Bearer","scope":"https://mail.google.com/"}

What this ends up meaning (as cryptic as the message is) is that the authentication token that you are using has expired. You need to invalidate it and then get a new one (simply request the token again).

You invalidate the token like this:

mAccountManager.invalidateAuthToken("con.google", mAuthenticationToken);

I hope that this is helpful :)