编码实现gmail中的附件

android问题：

我的代码已经实现了用gmail发送邮件，现在我需要发送的邮件可以添加附件，没有用户交互。谁能帮忙告诉一下怎么实现啊？

直接把代码给你吧

public synchronized void sendMail(String subject, String body, String sender, String recipients, File attachment) throws Exception {
    try{
    MimeMessage message = new MimeMessage(session);
    message.setSender(new InternetAddress(sender));
    message.setSubject(subject);

    MimeBodyPart mbp1 = new MimeBodyPart();
    mbp1.setText(body);

    MimeBodyPart mbp2 = new MimeBodyPart();
    FileDataSource fds = new FileDataSource(attachment);
    mbp2.setDataHandler(new DataHandler(fds));
    mbp2.setFileName(fds.getName());

    Multipart mp = new MimeMultipart();
    mp.addBodyPart(mbp1);
    mp.addBodyPart(mbp2);

    message.setContent(mp);

    if (recipients.indexOf(',') > 0)
        message.setRecipients(Message.RecipientType.TO, InternetAddress.parse(recipients));
    else
        message.setRecipient(Message.RecipientType.TO, new InternetAddress(recipients));
    Transport.send(message);
    }catch(Exception e){

    }
}