Develop Reference

p7s file and javamail

I use this code to read an email String in S/Mime format in a certificated email. This is a snippet
InputStream inputStreamObj = new ByteArrayInputStream(message.getBytes());
MimeMessage mimeMessageObj = new MimeMessage(session, inputStreamObj);
Object content = mimeMessageObj.getContent();
if (content instanceof Multipart) {
Multipart multiPart = (Multipart)content;
for (int i = 0; i < multiPart.getCount(); i++) {
BodyPart part = (MimeBodyPart) multiPart.getBodyPart(i);
if (part.getFileName() != null) {
System.out.println("Filename:"+part.getFileName());
} else if (part.getContent() instanceof Multipart) {
System.out.println("Multipart");
//here there is a recursive call to this method
} else if (part.getContent() instanceof String) {
System.out.println("Message text: "+part.getContent());
} else {
System.out.println("NOT RECOGNIZED TYPE");
}
}
}
In this manner I see:
Message text: <message in html form>
Message text: <message in txt form>
File: daticert.xml
File: postacert.eml
But here "smime.p7s" file is missing
How can I find this? In the String message (message) I see it:
Content-Type: application/x-pkcs7-signature; name="smime.p7s"
Content-Disposition: attachment; filename="smime.p7s"
Where is the file???
Maybe I cannot use MimeMessage and I must use javax.mail.Message? And how can I convert the text in Message?

Solved!
The message-text received contains all (headers + bodypart). When managed, it "loose" headers parts. Adding these in the first message-text I now see all the attachments, even p7s file.
This file, infact, is nested to the main email using a code binding (printing the txt you can see it), but this link suffer of missing headers. In this manner, without headers, noone can address the p7s file.
The solution is: add headers in the form "name: value\n" at the beginning of the txt-message.

java getDisposition returns null on emails with attachments

SO i'm making a mail client for a homework assignment and one of the requirements is to handle incoming attachments. The first thing I want to do is just show if an email even has an attachment or not. I have a bunch of AWT lists that are side by side for From, Subject, Size, Date, Attachment.
For testing purposes, if the disposition returns null, i just put an x in the attachmentList. If its inline, it puts an i and for attachments it should show the filename. However, even on emails where there are attachments and looking at the headers in gmail webmail, which shows the content disposition as attachment (all lower case), the getDisposition of the email still returns null. I don't get why its not returning ATTACHMENT or attachment or something besides null. Here is the relevant code.
for (int i = 0; i < messages.length; i++) {
Address[] froms = messages[i].getFrom();
String email = froms == null ? null : ((InternetAddress) froms[0]).getAddress();
fromList.add(email);
subjectList.add(messages[i].getSubject());
sizeList.add("" + messages[i].getSize());
dateList.add(messages[i].getReceivedDate().toString());
String disposition = messages[i].getDisposition();
System.out.println("Disposition is " + disposition + ".");
if (disposition == null) {
attachmentList.add("x");
}
else if ("INLINE".equalsIgnoreCase(disposition)) {
attachmentList.add("i");
}
else if ("ATTACHMENT".equalsIgnoreCase(disposition)) {
String fileName = messages[i].getFileName();
if (fileName != null) {
attachmentList.add("attachment " + fileName);
}
}
}
You'll notice that it prints "the disposition is..." which is another testing code and it always prints either null or INLINE. The particular email i'm looking at is about 700k and contains 2 attachments.

Look at the raw MIME text of the message and make sure the Content-Disposition header is set as you expect.
Turn on JavaMail session debugging and examine the protocol trace in the debug output.
Are you using IMAP to read the message? If so, the IMAP server parses the message and returns the "disposition" information in the IMAP protocol message. The IMAP server may not be parsing the message correctly or may not be returning the disposition information correctly.

Count of particular mail attachment without downloading attachment - using Java

Is it possible to get only the count of attachments for a mail in Java? I tried using this:
DataHandler handler = message.getDataHandler();
AttachedFileName= handler.getName();
This lists out all the attachments for all mails inbox but not for specific mails.
Is this possible if so how?
Thanks!

This should give you the attachment count,
Multipart multipart = (Multipart) message.getContent();
int attachmentCount = multipart.getCount();

I don't have enough reputation to comment on the accepted solution:
Multipart multipart = (Multipart) message.getContent();
int attachmentCount = multipart.getCount();
But I don't think that it is ideal for the following reasons:
Many email clients [For example: Thunderbird] send all HTML emails as multipart/alternative. They include a HTML part and an alternative plain text part. Historically, it was done to let clients choose the best alternative that they are capable of displaying.
Not everything included as a part is an attachment. For example, many images are not displayed as attachments in email clients because their disposition is set to "inline".
In summary, this solution potentially counts all HTML emails as having attachments and all emails with inline images as having attachments.
Here is an alternative that ignores parts not normally considered attachments:
private int getAttachmentCount(Message message) {
int count = 0;
try {
Object object = mMessage.getContent();
if (object instanceof Multipart) {
Multipart parts = (Multipart) object;
for (int i = 0; i < parts.getCount(); ++i) {
MimeBodyPart part = (MimeBodyPart) parts.getBodyPart(i);
if (Part.ATTACHMENT.equalsIgnoreCase(part.getDisposition()))
++count;
}
}
} catch (IOException | MessagingException e) {
e.printStackTrace();
}
return count;
}
I know that this solution gets the body part, but I believe that it is the only accurate way to see if it is an attachment.

I had a similar problem. The accepted answer didn't work for me because multipart may not necessarily be an attachment file. I counted the number of attachments by ignoring the other possible cases in multipart.
int count = 0;
Multipart multipart = (Multipart) message.getContent();
for(int i = multipart.getCount() - 1; i >= 0; i--)
{
BodyPart bodyPart = multipart.getBodyPart(i);
String bodyPartContentType = bodyPart.getContentType();
if(isSimpleType(bodyPartContentType)) continue;
else if(isMultipartType(bodyPartContentType)) continue;
else if(!isTextPlain(bodyPartContentType)) count++;
}
You can check simple type, multipart type, and text using these methods:
private boolean isTextPlain(String contentType)
{
return (contentType.contains("TEXT/PLAIN") || (contentType.contains("TEXT/plain")));
}
private boolean isSimpleType(String contentType)
{
if(contentType.contains("TEXT/HTML") || contentType.contains("text") ||
contentType.contains("TEXT/html")) return true;
return false;
}
private boolean isMultipartType(String contentType)
{
if(contentType.contains("multipart") || contentType.contains("multipart/mixed")) return true;
return false;
}
This worked for me.

How to handle multipart/alternative mail with JavaMail?

I wrote an application which gets all emails from an inbox, filters the emails which contain a specific string and then puts those emails in an ArrayList.
After the emails are put in the List, I am doing some stuff with the subject and content of said emails. This works all fine for e-mails without an attachment. But when I started to use e-mails with attachments it all didn't work as expected anymore.
This is my code:
public void getInhoud(Message msg) throws IOException {
try {
cont = msg.getContent();
} catch (MessagingException ex) {
Logger.getLogger(ReadMailNew.class.getName()).log(Level.SEVERE, null, ex);
}
if (cont instanceof String) {
String body = (String) cont;
} else if (cont instanceof Multipart) {
try {
Multipart mp = (Multipart) msg.getContent();
int mp_count = mp.getCount();
for (int b = 0; b < 1; b++) {
dumpPart(mp.getBodyPart(b));
}
} catch (Exception ex) {
System.out.println("Exception arise at get Content");
ex.printStackTrace();
}
}
}
public void dumpPart(Part p) throws Exception {
email = null;
String contentType = p.getContentType();
System.out.println("dumpPart" + contentType);
InputStream is = p.getInputStream();
if (!(is instanceof BufferedInputStream)) {
is = new BufferedInputStream(is);
}
int c;
final StringWriter sw = new StringWriter();
while ((c = is.read()) != -1) {
sw.write(c);
}
if (!sw.toString().contains("<div>")) {
mpMessage = sw.toString();
getReferentie(mpMessage);
}
}
The content from the e-mail is stored in a String.
This code works all fine when I try to read mails without attachment. But if I use an e-mail with attachment the String also contains HTML code and even the attachment coding. Eventually I want to store the attachment and the content of an e-mail, but my first priority is to get just the text without any HTML or attachment coding.
Now I tried an different approach to handle the different parts:
public void getInhoud(Message msg) throws IOException {
try {
Object contt = msg.getContent();
if (contt instanceof Multipart) {
System.out.println("Met attachment");
handleMultipart((Multipart) contt);
} else {
handlePart(msg);
System.out.println("Zonder attachment");
}
} catch (MessagingException ex) {
ex.printStackTrace();
}
}
public static void handleMultipart(Multipart multipart)
throws MessagingException, IOException {
for (int i = 0, n = multipart.getCount(); i < n; i++) {
handlePart(multipart.getBodyPart(i));
System.out.println("Count "+n);
}
}
public static void handlePart(Part part)
throws MessagingException, IOException {
String disposition = part.getDisposition();
String contentType = part.getContentType();
if (disposition == null) { // When just body
System.out.println("Null: " + contentType);
// Check if plain
if ((contentType.length() >= 10)
&& (contentType.toLowerCase().substring(
0, 10).equals("text/plain"))) {
part.writeTo(System.out);
} else if ((contentType.length() >= 9)
&& (contentType.toLowerCase().substring(
0, 9).equals("text/html"))) {
part.writeTo(System.out);
} else if ((contentType.length() >= 9)
&& (contentType.toLowerCase().substring(
0, 9).equals("text/html"))) {
System.out.println("Ook html gevonden");
part.writeTo(System.out);
}else{
System.out.println("Other body: " + contentType);
part.writeTo(System.out);
}
} else if (disposition.equalsIgnoreCase(Part.ATTACHMENT)) {
System.out.println("Attachment: " + part.getFileName()
+ " : " + contentType);
} else if (disposition.equalsIgnoreCase(Part.INLINE)) {
System.out.println("Inline: "
+ part.getFileName()
+ " : " + contentType);
} else {
System.out.println("Other: " + disposition);
}
}
This is what is returned from the System.out.printlns
Null: multipart/alternative; boundary=047d7b6220720b499504ce3786d7
Other body: multipart/alternative; boundary=047d7b6220720b499504ce3786d7
Content-Type: multipart/alternative; boundary="047d7b6220720b499504ce3786d7"
--047d7b6220720b499504ce3786d7
Content-Type: text/plain; charset="ISO-8859-1"
'Text of the message here in normal text'
--047d7b6220720b499504ce3786d7
Content-Type: text/html; charset="ISO-8859-1"
Content-Transfer-Encoding: quoted-printable
'HTML code of the message'
This approach returns the normal text of the e-mail but also the HTML coding of the mail. I really don't understand why this happens, I've googled it but it seems like there is no one else with this problem.
Any help is appreciated,
Thanks!

I found reading e-mail with the JavaMail library much more difficult than expected. I don't blame the JavaMail API, rather I blame my poor understanding of RFC-5322 -- the official definition of Internet e-mail.
As a thought experiment: Consider how complicated an e-mail message can become in the real world. It is possible to "infinitely" embed messages within messages. Each message itself may have multiple attachments (binary or human-readable text). Now imagine how complicated this structure becomes in the JavaMail API after parsing.
A few tips that may help when traversing e-mail with JavaMail:
Message and BodyPart both implement Part.
MimeMessage and MimeBodyPart both implement MimePart.
Where possible, treat everything as a Part or MimePart. This will allow generic traversal methods to be built more easily.
These Part methods will help to traverse:
String getContentType(): Starts with the MIME type. You may be tempted to treat this as a MIME type (with some hacking/cutting/matching), but don't. Better to only use this method inside the debugger for inspection.
Oddly, MIME type cannot be extracted directly. Instead use boolean isMimeType(String) to match. Read docs carefully to learn about powerful wildcards, such as "multipart/*".
Object getContent(): Might be instanceof:
Multipart -- container for more Parts
Cast to Multipart, then iterate as zero-based index with int getCount() and BodyPart getBodyPart(int)
Note: BodyPart implements Part
In my experience, Microsoft Exchange servers regularly provide two copies of the body text: plain text and HTML.
To match plain text, try: Part.isMimeType("text/plain")
To match HTML, try: Part.isMimeType("text/html")
Message (implements Part) -- embedded or attached e-mail
String (just the body text -- plain text or HTML)
See note above about Microsoft Exchange servers.
InputStream (probably a BASE64-encoded attachment)
String getDisposition(): Value may be null
if Part.ATTACHMENT.equalsIgnoreCase(getDisposition()), then call getInputStream() to get raw bytes of the attachment.
Finally, I found the official Javadocs exclude everything in the com.sun.mail package (and possibly more). If you need these, read the code directly, or generate the unfiltered Javadocs by downloading the source and running mvn javadoc:javadoc in the mail project module of the project.

Did you find these JavaMail FAQ entries?
How do I read a message with an attachment and save the attachment?
How do I tell if a message has attachments?
How do I find the main message body in a message that has attachments?

Following up on Kevin's helpful advice, analyzing your email content Java object types with respect to their canonical names (or simple names) can be helpful too. For example, looking at one inbox I've got right now, of 486 messages 399 are Strings, and 87 are MimeMultipart. This suggests that - for my typical email - a strategy that uses instanceof to first peel off Strings is best.
Of the Strings, 394 are text/plain, and 5 are text/html. This will not be the case for most; it's reflective of my email feeds into this particular inbox.
But wait - there's more!!! :-) The HTML sneaks in there nevertheless: of the 87 Multipart's, 70 are multipart/alternative. No guarantees, but most (if not all of these) are TEXT + HTML.
Of the other 17 multipart, incidentally, 15 are multipart/mixed, and 2 are multipart/signed.
My use case with this inbox (and one other) is primarily to aggregate and analyze known mailing list content. I can't ignore any of the messages, but an analysis of this sort helps me make my processing more efficient.

Listing attachment without downloading it using javamail api

I am developing a java mail client using javamail api. I need to fetch the list of attachment without fetching it. First i will display the list of attachments and than on click of a particular attachment, i will fetch the data. Currently i am able to fetch the name of all attachments but it is taking too long time since i think my code is also fetching the attachment data. My code is as below
private void getAttachmentList(Part part, List list) throws Exception{
Object content = part.getContent();
if(content instanceof Multipart){
Multipart multiPart = (Multipart)content;
int no_of_part = multiPart.getCount();
for(int i=0; i<no_of_part; i++){
getAttachmentList(multiPart.getBodyPart(i), list);
}
}else{
String disposition = part.getDisposition();
if (disposition != null && disposition.equalsIgnoreCase(Part.ATTACHMENT)) {
String fileName = part.getFileName();
if(fileName != null){
list.add(fileName);
}
}
}
}
I have tested this code with my gmail account and it is taking lots of time if my mail is having huge attachments. Any help is appreciated.
Thanks in advance

Do this app use POP, or IMAP?
If it uses POP, modify it to use IMAP. The latter may conceivably be quicker as it only downloads headers.