Downloading zip files - problem

Question

I have a program which is supposed to allow download of a zip file to the users PC and then write a record to a database showing that the user has downloaded the file.
When I try and read the file I have downloaded I get an error message which says the zip file is incomplete.
Here is the code which downloads the file
docname = material.getFilelocation().substring(slashpos+1,material.getFilelocation().length());
// reformat file name to work with getRealPath
material.setFilelocation(dirname+"\\" +docname);
//read data from file
sc= getServletContext();
String fileaddress = sc.getRealPath(material.getFilelocation());
File resfile = new File(fileaddress);
FileInputStream fileIn = new FileInputStream (resfile);
BufferedInputStream in = new BufferedInputStream(new DataInputStream(fileIn));
// Set up output to client
res.setContentType("application/zip");
res.addHeader("Content-Disposition", "inline;filename="+docname);
OutputStream ds=res.getOutputStream();
byte b[]=new byte[1024];
int len =0;
while ((len=in.read(b))>0) {
ds.write(b,0,len);
in.close();
getfilelocation has format -directory/filename.zip
Does anyone know why the file is incomplete?
Thanks
Suzan

Answer 1

while ((len=in.read(b))>0) {There you are. You stop reading the input when you
reach the first zero byte. The documentation for this
method says
"If no byte is available because the end of the
stream has been reached, the value -1 is returned."I doubt that's the problem. The API does say that -1 is returned on EOF, but if it isn't going to return -1, then it will read at least 1 byte, stuff that into the array, and return the number of bytes read - which won't be zero unless the size of the array passed to it is zero (which it isn't).