@Nonnull
private static Content processPart(MimePart part, MimePart parent)
throws MessagingException, IOException {
if (part == null) {
return new Content();
}
if (part.getFileName() != null) {
// Assume that a part which has a filename is an attachment.
return new Content(part);
}
if (part.isMimeType("text/*")) {
return getContent(part);
} else if (part.isMimeType("multipart/*")) {
if (part.isMimeType(MimeType.MULTIPART_RELATED)) {
return getContentWithAttachments(part);
} else if (part.isMimeType(MimeType.MULTIPART_ALTERNATIVE)) {
return getContentOfBestPart(part, parent);
} else {
return getJoinedContent(part);
}
}
return new Content();
}
private static Content getContentOfBestPart(MimePart part, MimePart parent)
throws IOException, MessagingException {
MimeBodyPart best = null;
MimeMultipart mp = (MimeMultipart) part.getContent();
for (int i = 0; i < mp.getCount(); i++) {
// Prefer HTML if the parent is a multipart/related part which may contain
// inline images, because text/plain cannot embed the images.
boolean isHtmlPreferred = parent != null && parent.isMimeType(MimeType.MULTIPART_RELATED);
best = better((MimeBodyPart) mp.getBodyPart(i), best, isHtmlPreferred);
}
return processPart(best, part);
}
private static Content getContentWithAttachments(MimePart part)
throws MessagingException, IOException {
Content result = new Content();
String rootId = new ContentType(part.getContentType()).getParameter("start");
MimeMultipart mp = (MimeMultipart) part.getContent();
for (int i = 0; i < mp.getCount(); i++) {
MimePart p = (MimePart) mp.getBodyPart(i);
if (isRootPart(p, i, rootId)) {
result = result.merge(processPart(p, part));
} else {
result.attachments.add(p);
}
}
return result;
}
private static Map<String, Attachment> saveAttachments(
Collection<MimePart> partsToAttach, Resource container)
throws MessagingException, IOException, NoSuchAlgorithmException {
Map<String, Attachment> result = new HashMap<>();
for (MimePart partToAttach : partsToAttach) {
Attachment attachment = saveAttachment(partToAttach, container);
if (partToAttach.getContentID() != null) {
String cid = partToAttach.getContentID().trim();
cid = cid.replace("<", "");
cid = cid.replace(">", "");
result.put(cid, attachment);
}
}
return result;
}
private static Content getJoinedContent(MimePart part) throws IOException, MessagingException {
Content result = new Content();
MimeMultipart mp = (MimeMultipart) part.getContent();
for (int i = 0; i < mp.getCount(); i++) {
MimeBodyPart p = (MimeBodyPart) mp.getBodyPart(i);
result.merge(processPart(p, part));
}
return result;
}
/**
* Returns true if the given part is root part.
*
* <p>The given part is root part, if the part is the first one and the given root id is not
* defined or the content id of the part equals to the given root id.
*
* @param part
* @param nthPart
* @param rootId
* @return
* @throws MessagingException
*/
private static boolean isRootPart(MimePart part, int nthPart, String rootId)
throws MessagingException {
return (rootId == null && nthPart == 0) || StringUtils.equals(part.getContentID(), rootId);
}
private static Content getContent(MimePart part) throws IOException, MessagingException {
Content result = new Content();
result.body = (String) part.getContent();
result.type = part.getContentType();
return result;
}
