private FileTransfer createFileTransfer(JID from,
                                            JID to, Element siElement) {
        String streamID = siElement.attributeValue("id");
        String mimeType = siElement.attributeValue("mime-type");
        // Check profile, the only type we deal with currently is file transfer
        Element fileTransferElement = getChildElement(siElement, NAMESPACE_SI_FILETRANSFER);
        // Not valid form, reject
        if (fileTransferElement == null) {
            return null;
        }
        String fileName = fileTransferElement.attributeValue("name");
        String sizeString = fileTransferElement.attributeValue("size");
        if (fileName == null || sizeString == null) {
            return null;
        }

        long size;
        try {
            size = Long.parseLong(sizeString);
        }
        catch (Exception ex) {
            return null;
        }

        return new FileTransfer(from.toString(), to.toString(), streamID, fileName, size, mimeType);
    }
Returns true if the proxy transfer should be matched to an existing file transfer
in the system.

@return Returns true if the proxy transfer should be matched to an existing file
transfer in the system.
xmppserver/src/main/java/org/jivesoftware/openfire/filetransfer/DefaultFileTransferManager.java