How to apply PKCS7 Siganture to a File

Question

How to apply PKCS7 Siganture to a File, I go through the BouncyCastle API, all it deal SMIME message.
Please suggest me how to make a PKCS7 signature to a simple business document(i.e XML File).
Thank s in advance

Answer 1

how to read from a file ? Probably the easiest way is to see the API documentation for java.io.BufferedReader
how to delete an item from a file Not knowing what kind of "item" it is I'd suggest building a BufferedReader that reads your input file. Walk through it one line at a time using the readLine method and if the item is not there then write it to a new file. When you get to the item you want to delete just don't write it out.
Further information on how to use file streams can be found here: http://java.sun.com/docs/books/tutorial/essential/io/filestreams.html