如何使用 BiWeekly 库和 Java Mail API 创建现有事件并发送更新？

我在用着BiWeekly http://sourceforge.net/projects/biweekly/库来创建 VEVENT，然后使用以下命令发送它Java 邮件 API https://java.net/projects/javamail/pages/Home。一切正常，但如何为现有事件创建更新，即当我收到更新的 VEVENT 时，它不会在日历中创建新事件，但会更新现有事件？

我尝试按以下方式设置顺序event.setSequence(2)，但它不起作用。收到电子邮件代理、Lotus Notes、Google Mail 后总会创建新事件。

这是我创建和发送事件的代码：

try {
            String from = "[email protected] /cdn-cgi/l/email-protection";
            String to = "[email protected] /cdn-cgi/l/email-protection";
            Properties prop = new Properties();
            prop.setProperty("mail.transport.protocol", "smtp");
            prop.setProperty("mail.host", "smtp.example.com");
            prop.setProperty("mail.user", "email");
            prop.setProperty("mail.password", "");

            Session session = Session.getDefaultInstance(prop, null);

            // Define message
            MimeMessage message = new MimeMessage(session);
            message.addHeaderLine("method=REQUEST");
            message.addHeaderLine("charset=UTF-8");
            message.addHeaderLine("component=VEVENT");

            message.setFrom(new InternetAddress(from));
            message.addRecipient(Message.RecipientType.TO, new InternetAddress(to));
            message.setSubject("Message Subject");

            StringBuffer sb = new StringBuffer();


            /*EVENT START*/
            VEvent event = new VEvent();
            event.setUid("ANATOLYTARNAVSKY123");
            event.setDescription("Invitation Description");
            event.setSummary("Invitation Description");
            event.setOrganizer("[email protected] /cdn-cgi/l/email-protection");
            event.setLocation("room");

            event.setSequence(sequence);


            Calendar start = Calendar.getInstance();
            start.add(Calendar.HOUR_OF_DAY, sequence + 2);
            Calendar end = Calendar.getInstance();
            end.add(Calendar.HOUR_OF_DAY, sequence + 2);

            event.setDateStart(start.getTime());
            event.setDateEnd(end.getTime());
            icals.addEvent(event);

            WriterChainText text = Biweekly.write(icals);
            String result = text.go(); 


            System.out.println(result);
            /*EVENT END*/

            StringBuffer buffer = sb.append(result);


            // Create the message part
            BodyPart messageBodyPart = new MimeBodyPart();

            // Fill the message
            messageBodyPart.setHeader("Content-Class", "urn:content-classes:calendarmessage");
            messageBodyPart.setHeader("Content-ID", "calendar_message");
            messageBodyPart.setDataHandler(new DataHandler( new ByteArrayDataSource(buffer.toString(), "text/calendar")));// very important

            // Create a Multipart
            Multipart multipart = new MimeMultipart();

            // Add part one
            multipart.addBodyPart(messageBodyPart);

            // Put parts in message
            message.setContent(multipart);

            // send message
            Transport.send(message);
        } catch (MessagingException me) {
            me.printStackTrace();
        } catch (Exception ex) {
            ex.printStackTrace();
        }

在这里，我将放置用于发送邀请的代码的迭代:

• 2nd: Added LAST-MODIFIED@Michael 建议的财产 http://pastebin.com/2NWhkgZb

先感谢您。

UPDATE 1:

这是我的代码和 BiWeekly 库生成的第一个和第二个 VEVENT：

仅创建事件 - 事件数据:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Michael Angstadt//biweekly 0.4.3//EN
METHOD:REQUEST
BEGIN:VEVENT
DTSTAMP:20151113T100301Z
UID:ANATOLYTARNAVSKY123
DESCRIPTION:Invitation Description
SUMMARY:Invitation Description
ORGANIZER:mailto:[email protected] /cdn-cgi/l/email-protection
LOCATION:room
SEQUENCE:0
DTSTART:20151113T120301Z
DTEND:20151113T120301Z
END:VEVENT
END:VCALENDAR

更新事件 - 仅 VEVENT 数据:

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Michael Angstadt//biweekly 0.4.3//EN
METHOD:REQUEST
BEGIN:VEVENT
DTSTAMP:20151113T100333Z
UID:ANATOLYTARNAVSKY123
DESCRIPTION:Invitation Description
SUMMARY:Invitation Description
ORGANIZER:mailto:[email protected] /cdn-cgi/l/email-protection
LOCATION:room
SEQUENCE:1
DTSTART:20151113T130333Z
DTEND:20151113T130333Z
END:VEVENT
END:VCALENDAR

UPDATE 2:

当我发送第一和第二次邀请时，我在 Gmail 上收到以下电子邮件：

完整的original由于此处的一些隐私问题，已删除跟踪路径的电子邮件内容：

创建事件 - 不含路由部分的完整电子邮件:

Date: Sat, 14 Nov 2015 08:03:47 -0700
From: [email protected] /cdn-cgi/l/email-protection
To: [email protected] /cdn-cgi/l/email-protection
Message-ID: *****
Subject: Escape Room Invitation
MIME-Version: 1.0
Content-Type: multipart/mixed; 
    boundary="----=_Part_0_451111351.1447513426727"
X-TM-AS-MML: disable
X-Content-Scanned: Fidelis XPS MAILER
x-cbid: 15111415-0021-0000-0000-000004CDC424

method=REQUEST
charset=UTF-8
component=VEVENT

------=_Part_0_451111351.1447513426727
Content-Type: text/calendar; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Class: urn:content-classes:calendarmessage
Content-ID: calendar_message

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Michael Angstadt//biweekly 0.4.3//EN
METHOD:REQUEST
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTAMP:20151114T150346Z
UID:[email protected] /cdn-cgi/l/email-protection
STATUS:CONFIRMED
DESCRIPTION:Invitation Description
SUMMARY:Invitation Summary
ORGANIZER:mailto:[email protected] /cdn-cgi/l/email-protection
LOCATION:Escape room
TRANSP:OPAQUE
CREATED:20151114T150346Z
LAST-MODIFIED:20151114T150346Z
SEQUENCE:0
DTSTART:20151114T170346Z
DTEND:20151114T170346Z
END:VEVENT
END:VCALENDAR

------=_Part_0_451111351.1447513426727--

更新事件 - 完整电子邮件，不含路由部分:

Date: Sat, 14 Nov 2015 08:05:06 -0700
From: anat[email protected] /cdn-cgi/l/email-protection
To: [email protected] /cdn-cgi/l/email-protection
Message-ID: *****
Subject: Escape Room Invitation
MIME-Version: 1.0
Content-Type: multipart/mixed; 
    boundary="----=_Part_0_451111351.1447513506015"
X-TM-AS-MML: disable
X-Content-Scanned: Fidelis XPS MAILER
x-cbid: 15111415-0029-0000-0000-000004D409DF

method=REQUEST
charset=UTF-8
component=VEVENT

------=_Part_0_451111351.1447513506015
Content-Type: text/calendar; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Class: urn:content-classes:calendarmessage
Content-ID: calendar_message

BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Michael Angstadt//biweekly 0.4.3//EN
METHOD:REQUEST
CALSCALE:GREGORIAN
BEGIN:VEVENT
DTSTAMP:20151114T150505Z
UID:[email protected] /cdn-cgi/l/email-protection
STATUS:CONFIRMED
DESCRIPTION:Invitation Description
SUMMARY:Invitation Summary
ORGANIZER:mailto:[email protected] /cdn-cgi/l/email-protection
LOCATION:Escape room
TRANSP:OPAQUE
CREATED:20151114T150505Z
LAST-MODIFIED:20151114T150505Z
SEQUENCE:1
DTSTART:20151114T180505Z
DTEND:20151114T180505Z
END:VEVENT
END:VCALENDAR

------=_Part_0_451111351.1447513506015--

UPDATE 3看起来它在 Lotus Notes 上工作正常，但 Google 日历仍然无法识别更新事件。

更新 4 - 解决方案

正如@arnaudq 所写，我错过了ATTENDEE属性使 Google 日历能够识别更新事件。以下是如何执行此操作的示例：

        VEvent event = new VEvent();
        ...
        Attendee attendee = new Attendee("Anatoly Tarnavsky", "[email protected] /cdn-cgi/l/email-protection");
        attendee.setRsvp(true);
        attendee.setRole(Role.CHAIR);
        attendee.setParticipationStatus(ParticipationStatus.CONFIRMED);
        ...
        event.setProperty(attendee);

您的代码似乎没有显式设置 UID 属性。因此，该库可能会为您生成一个新的。

UID 属性用于标识此 VEVENT 等。 因此，您的更新应包含与之前发送的原始事件相同的 UID 值。

您还缺少至少一项 ATTENDEE 属性。其中一位参加者应将其值设置为与接收邀请的 gmail 电子邮件地址相对应的 mailto uri。