Java未读邮件读取,邮件里的图片 java读取outlook邮件

使用JavaMail读取退信

在工作中遇到了一种场景，当我们向用户发送邮件后，偶尔会有一些用户投诉，未收到邮件，对于这种情况，我们需要一种方式来监控是否我们真的没有发送成功。我们使用的发件箱是outlook，当我们发送一个邮件到不存在的邮箱时，outlook会返回一个退信邮件，告知我们邮件并未送达，因此我们的解决方案就是解析该类邮件，并且对应到我们的发送记录中，话不多说直接上代码。

public class ReadMailTest {

    private static final String multipart = "multipart/*";
    private static final String userName = "";  //待读取的邮箱账户
    private static final String password = "";  //待读取的邮箱密码

    private static Properties buildInboxProperties() {
        Properties props = System.getProperties();
        props.setProperty("mail.imap.host", "imap.partner.outlook.cn");
        props.setProperty("mail.imap.socketFactory.class", "javax.net.ssl.SSLSocketFactory");
        props.setProperty("mail.imap.socketFactory.fallback", "false");
        props.setProperty("mail.imap.port", "993");
        props.setProperty("mail.imap.socketFactory.port", "993");
        props.setProperty("mail.imap.auth", "true");
        return props;
    }


    public static void searchInboxEmail() {
        Session session = Session.getInstance(buildInboxProperties());
        URLName url = new URLName("imap", "imap.partner.outlook.cn", 993, null, userName, password);
        try(Store store = session.getStore(url)) {
            store.connect();
            try (Folder receiveFolder = store.getFolder("inbox")) {
                receiveFolder.open(Folder.READ_ONLY);
                int messageCount = receiveFolder.getMessageCount();
                if (messageCount > 0) {
                    //添加日期条件
                    Date beforeDate = Date.from(LocalDateTime.now().minusHours(3).atZone(ZoneId.systemDefault()).toInstant());
                    SearchTerm comparisonTermGe = new SentDateTerm(ComparisonTerm.GE, beforeDate);
                    //添加内容条件，内容中存在Original message headers的邮件为退信邮件
                    BodyTerm bodyTerm = new BodyTerm("Original message headers");
                    SearchTerm search = new AndTerm(comparisonTermGe, bodyTerm);
                    // 调用搜索api
                    Message[] messages = receiveFolder.search(search);
                    if (messages.length == 0) {
                        return;
                    }
                    /* 由于Javamail不支持按照时间进行过滤，只支持到日期，因此如果需要精确到时间过滤
                        需要在获取到搜索结果后再过滤一次*/
                    List<Message> messageList = Stream.of(messages)
                            .filter(message -> {
                                try {
                                    return !message.getSentDate().before(beforeDate);
                                } catch (MessagingException e) {
                                    e.printStackTrace();
                                }
                                return false;
                            })
                            .collect(Collectors.toList());
                    messageHandler(messageList);
                    System.out.println(messageList.size());
                }
            }
        } catch (MessagingException e) {
            e.printStackTrace();
        }
    }

    public static void messageHandler(List<Message> messages) {
        messages.stream()
                .filter(ReadMailTest::isContainAttachment)
                .forEach(message -> {
                    String messageId = null;
                    try {
                        messageId = getMessageId(message);
                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                    try {
                        System.out.println("subject=" + message.getSubject() + ",messageId=" + messageId + ",sendDate=" + message.getSentDate());
                    } catch (MessagingException e) {
                        e.printStackTrace();
                    }
                });
    }

    public static String getMessageId(Part part) throws Exception {
        if (!part.isMimeType(multipart)) {
            return "";
        }

        Multipart multipart = (Multipart) part.getContent();
        for (int i = 0; i < multipart.getCount(); i++) {
            BodyPart bodyPart = multipart.getBodyPart(i);

            if (part.isMimeType("message/rfc822")) {
                return getMessageId((Part) part.getContent());
            }
            InputStream inputStream = bodyPart.getInputStream();

            try (BufferedReader br = new BufferedReader(new InputStreamReader(inputStream))) {
                String strLine;
                while ((strLine = br.readLine()) != null) {
                    if (strLine.startsWith("Message-ID:")) {
                        String[] split = strLine.split("Message-ID:");
                        return split.length > 1 ? split[1].trim() : null;
                    }
                }
            }
        }

        return "";
    }

    public static boolean isContainAttachment(Part part) {
        boolean attachFlag = false;
        try {
            if (part.isMimeType(multipart)) {
                Multipart mp = (Multipart) part.getContent();
                for (int i = 0; i < mp.getCount(); i++) {
                    BodyPart mpart = mp.getBodyPart(i);
                    String disposition = mpart.getDisposition();
                    if ((disposition != null) && ((disposition.equals(Part.ATTACHMENT)) || (disposition.equals(Part.INLINE))))
                        attachFlag = true;
                    else if (mpart.isMimeType(multipart)) {
                        attachFlag = isContainAttachment(mpart);
                    } else {
                        String contype = mpart.getContentType();
                        if (contype.toLowerCase().contains("application"))
                            attachFlag = true;
                        if (contype.toLowerCase().contains("name"))
                            attachFlag = true;
                    }
                }
            } else if (part.isMimeType("message/rfc822")) {
                attachFlag = isContainAttachment((Part) part.getContent());
            }
        } catch (MessagingException | IOException e) {
            e.printStackTrace();
        }
        return attachFlag;
    }
}

上面的代码是读取退信邮件，根据过滤条件，也可以读取其他自己想要读取的邮件