Can XML bring along pdf file?
Depends on what you mean by "bring along".
The usual solution would be to have the XML file contain a URI which
tells the application where it can fetch the PDF file -- the same way
that a website can contain a link to a PDF file.
If you really need to embed the PDF in the XML, it's going to be
inefficient. XML can't contain arbitrary binary data, so the usual
solution is to base-64 encode the non-XML information and include the
resulting text characters as content of the XML document. Which, of
course, requires decoding back into the binary form on the far end. Base
64 also increases the number of bytes that must be transmitted. Not a
recommended solution unless you have specific reasons for doing it this way.