Uploading an Image File

Greenhorn

Posts: 4

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Hi,
I am working for uploading an image file.It is uploading on the same machine but not working on net..It is not getting the path of the server while copying and path not found exception occurs.I am not using Orilly's Multi Part Classes.
I am giving my codes for your reference..

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class uploadServlet extends HttpServlet
{
FileInputStream fis=null;
FileOutputStream fos=null;;
PrintWriter out;
String sourcefile="";
String source="";
String extn="";
public void doGet(HttpServletRequest req,HttpServletResponse res) throws ServletException, IOException
{
//res.setContentType("image/jpg");
res.setContentType("text/html");
out = res.getWriter();
try
{
 source=req.getParameter("sourcenm");
int len = source.length();
int pos = source.lastIndexOf('\\');
sourcefile=source.substring(pos+1);
int posext=sourcefile.lastIndexOf('.');
extn=sourcefile.substring(posext+1);
out.println("<html><body bgcolor='FF9966'>");
out.println("<table><tr><td>File name is : </td><br><td>");
out.println(sourcefile);
out.println("Extention of File is "+extn);
out.println("   ");
out.println("</td></tr></table>");
this.fileReadWrite();
   }
   catch(Exception ie)
   {
out.println("Exception caught" + ie);
}
out.println("</body></html>");
}
public void doPost(HttpServletRequest req,HttpServletResponse res) throws ServletException, IOException
{
doGet(req,res);
}

public void fileReadWrite()
{
try
{
fis = new FileInputStream(source);
File file=new File(source);
long filesz=file.length();
out.println("size is "+filesz);
if (filesz<1200)
{
    byte b[] = new byte[1200];
    fis.read(b);
    fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
    fos.write(b);
     }
else if (filesz>1200 && filesz<5000)
  {
    byte b[] = new byte[5000];
    fis.read(b);
fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
fos.write(b);
      }
else if(filesz>5000 && filesz<15000)
  {
    byte b[] = new byte[15000];
    fis.read(b);
fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
fos.write(b);
      }
else if(filesz>15000 && filesz<25000)
  {
    byte b[] = new byte[25000];
    fis.read(b);
fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
fos.write(b);
      }
else if(filesz>25000 && filesz<40000)
  {
byte b[] = new byte[40000];
fis.read(b);
fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
fos.write(b);
      }
else if(filesz>40000 && filesz<50000)
  {
byte b[] = new byte[50000];
fis.read(b);
fos = new FileOutputStream("c:\\temp\\"+sourcefile,true);
fos.write(b);
      }
else if(filesz>50000)
   {
    out.println("<script>");
out.println("{");
out.println("alert('Image file should be more than 50K ');");
out.println("return false;");
out.println("}");
 out.println("</script>");
   }
}
catch(FileNotFoundException fone)
{
out.println("File not found.concentrate.."+fone);
}
catch(IOException ioe)
{
out.println("Error in IO "+ioe);
}
finally
{
try
{
fis.close();
fos.close();
}
catch(IOException io)
{
out.println("IO exception caught while file closing");
}
}
}
}

Can anyone can guide me?
Thanks in advance.
Bipul Bhattacharjee.

William Brogden

Author and all-around good cowpoke

Posts: 13078

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

This code is so loaded with problems it is hard to know where to start. You appear to be trying to create a page that mixes up HTML code characters with binary image data. This is NOT the way HTML pages with images are created. Look at the code of any HTML page that has images in it - you will see an <img> tag for each image. The browser fetches the binary image data as a separate operation. Any servlets book will have material on how to get a servlet to serve up images.
A second problem is that you are using instance variables all over the place. Remember that a servlet object may be handling requests from more than one browser at the same time - you can't use instance variables for data that is unique to a particular request.
Bill

------------------
author of:

Bipul Bhattacharjee

Greenhorn

Posts: 4

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Thanks a lot Bill.
But my problem is that I am writing servlet code which lets the client to upload an image file from the client's harddisk to my web server.
Any more suggestion.
Thanks a lot.
Bipul

Subbu Aswathanarayan

Ranch Hand

Posts: 73

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Hi Bill,
I am new to servlets and jsp.when u say that avoid instance variables,do you mean to say that all the variables must be declared inside the doGet() method.
Thanks for your help.
Subbu

Originally posted by William Brogden:
A second problem is that you are using instance variables all over the place. Remember that a servlet object may be handling requests from more than one browser at the same time - you can't use instance variables for data that is unique to a particular request.
Bill

Subbu

William Brogden

Author and all-around good cowpoke

Posts: 13078

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Bipul -
If you are expecting binary data from the Post, why are you opening a FileInputStream on the servlet side? Jason Hunter's web site has a widely used file-upload package - look at
http://www.servlets.com/
==============
Instance variables like:
FileInputStream fis=null;
FileOutputStream fos=null;;
PrintWriter out;
String sourcefile="";
String source="";
String extn="";
will be visible to every users request so the potential for mixup is incredible. You should be using variables created inside doGet or doPost - these local variables are visible only to the Thread that creates them. If you need to preserve values between request/response cycles, thats what sessions are for.
Bill

Subbu Aswathanarayan

Ranch Hand

Posts: 73

posted 23 years ago

Number of slices to send:

Optional 'thank-you' note:

Send

Hi Bill,
thanks for ur reply.
i have written a servlet which right now uses 4 instance variables.i cannot declare theses variables inside the doGet or doPost methods because, these variables are accessed by other methods in the servlet.what do i do now?is there a way out?
Subbu

Subbu

If you have a bad day in October, have a slice of banana cream pie. And this tiny ad:

Smokeless wood heat with a rocket mass heater

https://woodheat.net