Download servlet from external server

Question

I write a download file servlet. It should download files from external ftp and make the save as dialog window save it with proper extension.
It gets 3 parametes:
http://10.60.1.1:8080/sd-sp45/DownloadServlet?fileName=55555.doc&filePath=000/000/000/000/000/000/010/002/8c8/f07/57/00000000-0000-0000-0001-00028c8f076e&fileType=doc
fileName - original file name;
filePath - path and file name on ftp server;
fileType - file type;
I get an error IOException : java.oi.FileNotFoundException :
ftp:\sdattach:[email protected]\sdftp\Servicecall\000\000\000/000\000/000/010\002\8c8\f07\57\00000000-0000-0000-0001-00028c8f076e (The file name, diroctory name, or volume label syntax is incorrect)
I'm not sure if I can use here File class (maybe some network stuff)
Besides, what shoud I change here :
response.setContentType("application/octet-stream");
response.setContentLength((int)F.length());
response.setHeader("Content-Disposition","attachment;filename="+file);
to save file with the extension i need?
Thank you for help
import java.net.*;
import java.io.*;
import java.util.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.net.*;
public class DownloadServlet extends HttpServlet {
    File F;
    BufferedInputStream fif;
    ServletOutputStream stream;
    public void init(){
        F=null;
        fif=null;
        stream =null;
    public void doGet(HttpServletRequest request ,HttpServletResponse response) {
        try{
            try{
            // Setting Buffer size
            response.setBufferSize(50000);
            int buffersize;
            String filePath="";
            String fileName="";
            String fileType="";
            //Receiving variables
            fileName=request.getParameter("fileName");
            filePath = request.getParameter("filePath");
            fileType = request.getParameter("fileType");
            System.out.println("========New compile==");
            System.out.println(fileName);
            System.out.println(filePath);
            System.out.println(fileType);
            String downloadFile = "ftp://sdattach:[email protected]/sdftp/Servicecall/" + filePath;
            F=new File(downloadFile);
            String file=F.getName();
            buffersize= 10248;
            byte b[]=new byte[buffersize];
            // Setting Content Type
            response.setContentType("application/octet-stream");
            response.setContentLength((int)F.length());
            response.setHeader("Content-Disposition","attachment;filename="+file);
            stream = response.getOutputStream();
            fif = new BufferedInputStream(new FileInputStream(F));
            //writing data to output stream
            int count=fif.read(b,0,buffersize);
            while(count!=-1){
            stream.write(b,0,count);
            count=fif.read(b,0,buffersize);
            //closing objects
            fif.close();
            stream.flush();
            stream.close();
            F.delete();
            }catch(SocketException se){
            System.out.println("SocketException " +se);
            catch(IOException io){
            System.out.println("IOException " + io);
            catch(Exception e){
            System.out.println("Exception " +e);
        }catch(Exception e){ System.out.println("Exception " +e); }
}

Answer 1

assuming the filepath is absolutely correct, try doing this:
String downloadFile = "ftp://sdattach:[email protected]/sdftp/Servicecall/" + filePath;
response.setHeader("Content-Disposition","attachment;filename=\""+downloadFile+ "\"");