Using a servlet to send binary data

Question

There is a section of our intranet that need to hold documents that have to be available only for a certain group of users. Here's my approach (if you think of a better one, please tell me):
1-all the files are in a directory upper than WWWRoot so that nobody can directly download them
2-there is a servlet that first: authentificate the user with username-password; and then lists all available documents.
3-When one of these docs is clicked, I want my servlet to open the file using filesystem File object and then copy the content of the selected file in the http response body. What object and method should I use to do so? I dont know if I should use FileReader or something else. Dont forget it will not only has to work with text files, but also with binary data files like swf, powerpointpresentation and the like. So I fear that objects such as FileRead will mess special characters up and corrupt data.
What would you advice me? Use FileReader or another object? Or maybe a completly different approach for the problem? And if you want to give me some sample codes, it would be appreciated.
Thx for your help

Answer 1

There is something I dont understand.. its bizarre. Usually I dont understand why a script is not working, but now, I dont understand why a scritp is working..
Here are the codes that copy from a file to the servlet's ouput:
//basic response configurations
response.setContentType( mimeType );
ServletOutputStream out = response.getOutputStream();
//copy a file f to the servlet's output stream
File f = new File( path );
FileInputStream fis= new FileInputStream(f);
int available = fis.available();
byte[] b = new byte[available];
fis.read(b);
out.write( b );
out.flush();
They work fine. What I dont understand is that I tried them with a file of about 5 megs, and they still worked! I expected them to fail because the variable available is of the type int and then it implies that the maximum file size permitted by the algorithm should be 65536 bytes/1024=64 ko... isn't it????