java - EWS Java API 获取附件

Question

我在使用 ews java API 1.3 SNAPSHOT 获取一些附件时遇到一些问题，我想在我的电子邮件中获取附件，这里是我的代码:

try {
    ExchangeService service;
    service.setUrl(new URI("https://" + myserver + "/ews/Exchange.asmx"));
    ExchangeCredentials credentials = new WebCredentials(username, password);
    service.setCredentials(credentials);
    ItemView view = new ItemView(Integer.MAX_VALUE);
    view.getOrderBy().add(ItemSchema.DateTimeReceived, SortDirection.Ascending);
    Folder folder = Folder.bind(service, WellKnownFolderName.Inbox);
    FindItemsResults<Item> results = service.findItems(folder.getId(),view);
    service.loadPropertiesForItems(results, new PropertySet(BasePropertySet.FirstClassProperties, EmailMessageSchema.Attachments));

        for (Item item : results) {
        Item itm = Item.bind(service, item.getId(), new PropertySet(BasePropertySet.FirstClassProperties, EmailMessageSchema.Attachments));
        EmailMessage emailMessage = EmailMessage.bind(service, itm.getId(), new PropertySet(BasePropertySet.FirstClassProperties, EmailMessageSchema.Attachments));
        if (emailMessage.getHasAttachments()) {
                for (Attachment attachment : emailMessage.getAttachments()) {
                    String FileExtension = getFileExtension(attachment.getName());
                    File TempFile = File.createTempFile(attachment.getName(), FileExtension);
                    attachment.load(TempFile.getAbsolutePath());
                }
            }
        }
} catch (Exception e) {
    logger.error("Error ", e.getMessage());
}

我的问题是它可以获取另一封没有附件的电子邮件，并且总是跳过有附件的电子邮件，示例如下， 我的收件箱中有此电子邮件列表

• 发件人:a@gmail.com(有附件)
• 发件人:b@mycompany.com(无附件)
• 发件人:c@hiscompany.com(有附件)
• 发件人:d@mycompany.com(无附件)

当我运行我的代码时，它总是收到没有附件的电子邮件，如下所示:

• 发件人:b@mycompany.com(无附件)
• 发件人:d@mycompany.com(无附件)

并跳过其他带有附件的电子邮件，我不知道怎么会发生这种情况。有人可以帮我吗？

Answer 1

HashMap<String, HashMap<String, String>> attachments = new HashMap<String, HashMap<String, String>>();    

if (emailMessage.getHasAttachments() || emailMessage.getAttachments().getItems().size() > 0) {

        //get all the attachments
        AttachmentCollection attachmentsCol = emailMessage.getAttachments();

        log.info("File Count: " +attachmentsCol.getCount());

        //loop over the attachments
        for (int i = 0; i < attachmentsCol.getCount(); i++) {
            Attachment attachment = attachmentsCol.getPropertyAtIndex(i);
            //log.debug("Starting to process attachment "+ attachment.getName());

               //FileAttachment - Represents a file that is attached to an email item
                if (attachment instanceof FileAttachment || attachment.getIsInline()) {

                    attachments.putAll(extractFileAttachments(attachment, properties));

                } else if (attachment instanceof ItemAttachment) { //ItemAttachment - Represents an Exchange item that is attached to another Exchange item.

                    attachments.putAll(extractItemAttachments(service, attachment, properties, appendedBody));
                }
            }
        }
    } else {
        log.debug("Email message does not have any attachments.");
    }


//Extract File Attachments
try {
    FileAttachment fileAttachment = (FileAttachment) attachment;
    // if we don't call this, the Content property may be null.
    fileAttachment.load();

    //extract the attachment content, it's not base64 encoded.
    attachmentContent = fileAttachment.getContent();

    if (attachmentContent != null && attachmentContent.length > 0) {

        //check the size
        int attachmentSize = attachmentContent.length;

        //check if the attachment is valid
        ValidateEmail.validateAttachment(fileAttachment, properties,
                emailIdentifier, attachmentSize);

        fileAttachments.put(UtilConstants.ATTACHMENT_SIZE, String.valueOf(attachmentSize));

        //get attachment name
        String fileName = fileAttachment.getName();
        fileAttachments.put(UtilConstants.ATTACHMENT_NAME, fileName);

        String mimeType = fileAttachment.getContentType();
        fileAttachments.put(UtilConstants.ATTACHMENT_MIME_TYPE, mimeType);

        log.info("File Name: " + fileName + "  File Size: " + attachmentSize);


        if (attachmentContent != null && attachmentContent.length > 0) {
            //convert the content to base64 encoded string and add to the collection.
            String base64Encoded = UtilFunctions.encodeToBase64(attachmentContent);
            fileAttachments.put(UtilConstants.ATTACHMENT_CONTENT, base64Encoded);
        }



//Extract Item Attachment
try {
    ItemAttachment itemAttachment = (ItemAttachment) attachment;

    PropertySet propertySet = new PropertySet(
            BasePropertySet.FirstClassProperties, ItemSchema.Attachments, 
            ItemSchema.Body, ItemSchema.Id, ItemSchema.DateTimeReceived,
            EmailMessageSchema.DateTimeReceived, EmailMessageSchema.Body);

    itemAttachment.load();
    propertySet.setRequestedBodyType(BodyType.Text);

    Item item = itemAttachment.getItem();

    eBody = appendItemBody(item, appendedBody.get(UtilConstants.BODY_CONTENT));

    appendedBody.put(UtilConstants.BODY_CONTENT, eBody);

    /*
     * We need to check if Item attachment has further more
     * attachments like .msg attachment, which is an outlook email
     * as attachment. Yes, we can attach an email chain as
     * attachment and that email chain can have multiple
     * attachments.
     */
    AttachmentCollection childAttachments = item.getAttachments();
    //check if not empty collection. move on
    if (childAttachments != null && !childAttachments.getItems().isEmpty() && childAttachments.getCount() > 0) {

        for (Attachment childAttachment : childAttachments) {

            if (childAttachment instanceof FileAttachment) {

                itemAttachments.putAll(extractFileAttachments(childAttachment, properties, emailIdentifier));

            } else if (childAttachment instanceof ItemAttachment) {

                itemAttachments = extractItemAttachments(service, childAttachment, properties, appendedBody, emailIdentifier);
            }
        }
    }
} catch (Exception e) {
    throw new Exception("Exception while extracting Item Attachments: " + e.getMessage());
}