迭代地使用java邮件从邮件中获取所有附件

Question

以下是我可以用来从邮件中获取所有附件的递归方法。

public List<InputStream> getAttachments(Message message) throws Exception {
        Object content = message.getContent();
        if (content instanceof String)
            return null;        

        if (content instanceof Multipart) {
            Multipart multipart = (Multipart) content;
            List<InputStream> result = new ArrayList<InputStream>();

            for (int i = 0; i < multipart.getCount(); i++) {
                result.addAll(getAttachments(multipart.getBodyPart(i)));
            }
            return result;

        }
        return null;
    }

    private List<InputStream> getAttachments(BodyPart part) throws Exception {
        List<InputStream> result = new ArrayList<InputStream>();
        Object content = part.getContent();
        if (content instanceof InputStream || content instanceof String) {
            if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition()) || StringUtils.isNotBlank(part.getFileName())) {
                result.add(part.getInputStream());
                return result;
            } else {
                return new ArrayList<InputStream>();
            }
        }

        if (content instanceof Multipart) {
                Multipart multipart = (Multipart) content;
                for (int i = 0; i < multipart.getCount(); i++) {
                    BodyPart bodyPart = multipart.getBodyPart(i);
                    result.addAll(getAttachments(bodyPart));
         }
    }
    return result;
}

这可以通过简单地使用迭代来实现而不会递归，因为递归会占用堆栈中相当大的空间吗？