BufferedOutputStream writing garbage data

Question

I am writing download servlet that reads a html file and writes to servletOutputStream , the problem right at the of the file transferred it is adding some garbage data any suggestions about this,

below is code I am using for this

---

        int BUFFER_SIZE = 1024 * 8;
        servOut   = response.getOutputStream();
        bos       = new BufferedOutputStream(servOut);
        fileObj = new File(file);
        fileToDownload = new FileInputStream(fileObj);
        bis = new BufferedInputStream(fileToDownload);
        response.setContentType("application/text/html");
          response.setHeader("ContentDisposition","attachment;filename="+dump+".html");
        byte[] barray = new byte[BUFFER_SIZE];
        while ((bis.read(barray, 0, BUFFER_SIZE)) != -1) {
            bos.write(barray, 0, BUFFER_SIZE);
        }
        bos.flush();

Answer 1

bis.read returns the number of bytes read. You need to take that into account in your write call.

Something like:

int rd;
while ((rd=bis.read(...)) != -1) {
     bos.write(..., rd);
}

Answer 2

The problem is with the following part of your code:

        while ((bis.read(barray, 0, BUFFER_SIZE)) != -1) {
            bos.write(barray, 0, BUFFER_SIZE);
        }

You are always writing out a multiple of BUFFER_SIZE bytes, even if the size of your input isn't a multiple of BUFFER_SIZE . This results in garbage being written at the end of the last block.

You can fix it like so:

        int read;
        while ((read = bis.read(barray, 0, BUFFER_SIZE)) != -1) {
            bos.write(barray, 0, read);
        }