How do I get the byte size of a server file before sending output via HTTP?

Question

I need to get the byte size of the file prior to streaming it. I can't seem to find a class/method I need. Basically, I have the path c:\\tomcat\\webapps\\documents\\sample.pdf in the servlet, I was hoping I could just use something from the File class but I couldn't find anything that seems to do the trick?
thanks, in advance,
Chuck

Answer 1

maybe the source of the problem will help...I am trying to stream a PDF to IE and a blank page is being generated although all other file type work.
I have found a lot of answers in the forum but no specific code examples. Here's what I have so far from picking through threads in here (can someone please show me how to get the byte size of the file so that I can assign it to the method response.setContentLength();?):
String CONTENT_TYPE = " ";
     String target = " ";
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
     StringBuffer buf = new StringBuffer();
     HttpSession session = request.getSession();
     String file = request.getParameter("filename");
     target = file;
     int end = file.length();
int beg = end-2;
     String type = file.substring(beg, end);
     if (type.equals("DOC")){
          CONTENT_TYPE = "application//vnd.msword";
     }else if (type.equals("XLS")){
          CONTENT_TYPE = "application//vnd.x-excel";
     }else if (type.equals("PPT")){
          CONTENT_TYPE = "application//vnd.ms-powerpoint";
     }else if (type.equals("PDF")){
          CONTENT_TYPE = "application//vnd.x-pdf";
     }else if (type.equals("MPP")){
          CONTENT_TYPE = "application//vnd.ms-project";
     }else if (type.equals("ZIP")){
          CONTENT_TYPE = "application//ZIP";
     }else if (type.equals("TXT")){
          CONTENT_TYPE = "text//plain";
     }else {
          CONTENT_TYPE = "text//html";
     //File f = new File(file);
     //int l = f.length();
     response.setContentLength(l); <----- supposedly this fixes my problem but I don't know how to get the byte szie of the file in an integer??
     // reset the response
     response.reset();
     response.setContentType(CONTENT_TYPE);
     try{
     // Get streams
     FileInputStream fileInputStream = new FileInputStream(target);
     ServletOutputStream servletOutputStream = response.getOutputStream();
     // Init byte count and array
     int bytesRead = 0;
     byte byteArray[] = new byte[4096];
     // Read in bytes through file stream, and write out through servlet stream
     while((bytesRead = fileInputStream.read(byteArray)) != -1) {
     servletOutputStream.write(byteArray, 0, bytesRead);
          servletOutputStream.flush();
     // Flush and close streams
     servletOutputStream.flush();
     servletOutputStream.close();
     fileInputStream.close();
     } catch (Exception e) {
     System.out.println(e.toString());