JavaMail. IMAP Search using a literal on Gmail - jakarta-mail

Question

I need a help with next question:
I need to do a search using non-ascii characters on Gmail (Cyrillic alphabet (for example Russian or Ukrainian)). When I use the standard IMAP SEARCH command I receive an error:
A12 SEARCH CHARSET UTF-8 SUBJECT "текст" ALL
A12 BAD Could not parse command
In Java, it looks like
Message[] foundMessages = imapFolder.search(new SubjectTerm("текст"));
I've found some help here IMAP search for non-ascii characters. Using openssl s_client -crlf -connect imap.gmail.com:993 I've connected to my mailbox via Terminal and I've received next results:
A12 SEARCH CHARSET UTF-8 X-GM-RAW {10}
+ go ahead
текст
* SEARCH 226
A13 OK SEARCH completed (Success)
The main question - How to implement this in Java?
UPDATE
I've done some research on JavaMail source code. I've found next lines
// if server supports UTF-8, enable it for client use
// note that this is safe to enable even if mail.mime.allowutf8=false
if (p.hasCapability("UTF8=ACCEPT") || p.hasCapability("UTF8=ONLY"))
p.enable("UTF8=ACCEPT");
}
and from gmail server we receive next capabilities
A1 LOGIN test#gmail.com password
* CAPABILITY IMAP4rev1 UNSELECT IDLE NAMESPACE QUOTA ID XLIST CHILDREN
X-GM-EXT-1 UIDPLUS COMPRESS=DEFLATE ENABLE MOVE CONDSTORE ESEARCH
UTF8=ACCEPT LIST-EXTENDED LIST-STATUS
LITERAL-SPECIAL-USE APPENDLIMIT=35651584
So, JavaMail sets mail.mime.allowutf8 to true automatically. But in this case, JavaMail does a search using next command
C6 SEARCH CHARSET UTF-8 X-GM-RAW "текст" ALL
And I receive an error
C6 BAD Could not parse command
I've gone ahead and investigated
https://github.com/javaee/javamail/blob/52e04fc107d0b83fa794e6f622f7c76b9e85e395/mail/src/main/java/com/sun/mail/iap/Argument.java#L313
Argument.nastring(byte[] bytes, Protocol protocol, boolean doQuote)
boolean utf8 = protocol.supportsUtf8(); --> For Gmail it's true. That's why JavaMail doesn't use a literal.
byte b;
for (int i = 0; i < len; i++) {
b = bytes[i];
if (b == '\0' || b == '\r' || b == '\n' ||
(!utf8 && ((b & 0xff) > 0177))) {
// NUL, CR or LF means the bytes need to be sent as literals
literal(bytes, protocol);
return;
}
if (b == '*' || b == '%' || b == '(' || b == ')' || b == '{' ||
b == '"' || b == '\\' ||
((b & 0xff) <= ' ') || ((b & 0xff) > 0177)) {
quote = true;
if (b == '"' || b == '\\') // need to escape these characters
escape = true;
}
}
I've tested other email provider which doesn't have UTF8=ACCEPT. And all work fine.
K11 SEARCH CHARSET UTF-8 SUBJECT {10}
+ continue
текст ALL
* SEARCH 1194
K11 OK SEARCH completed

Answer 1

From a quick look at the source, it ought to Just Work if you use javamail 1.6.1. You may want/need to set the mail.mime.allowutf8 property to true.
In more detail: 1.6 adds support for unicode email addresses such as jøran#blåbærsyltetøy­.gulbrandsen.priv.no, which as a side effect regularises the use of UTF8 almost everywhere. When you connect to gmail, javamail 1.6 ought to send a login command, then automatically one along the lines of a04 enable utf8=accept and once gmail has acked utf8=accept, a12 search subject "текст" all becomes legal syntax that ought to do what you want.