Can you provide more information regarding the XML?  Does it actually contain the base64 string that represents the file or is it just a bunch of URL's?  If it is just URL's, are those the target URL's and where is the file to upload?

Thanks erice for the prompt reply. the xml has the just the urls. But i got this problem solved. i have written a custom code to read all the files and convert them to base 64 pattern and then upload to my sharepoint doc lib.

and those urls were the file addresses ie source file address.