Uploading a file using JSP

Inderjeet · October 20th, 2004, 04:20 AM

I have to upload a file from client browser to server database(not in any folder) using JSP-servlets(without struts). How can I do this? Can you provide me a simple code snippet?

angrycat · October 20th, 2004, 02:28 PM

You can send data from a standard HTML form if you want, it doesnt have to be JSP, you need to use the POST method within the form.

You will need to write a servlet to parse the data (removing headers added by the post action) back to its original form.

I found the following tutorial helpful, there is a section "reading get and post values" about half way down.

There is an error in the source code given in one of the loops, but its a good start:

http://java.sun.com/developer/online...k/aucserv.html

Inderjeet · October 20th, 2004, 11:35 PM

Hi
I have gone through the link sent by you. but it doesn't provide the solution to store the file in the database, it just gives the method to upload a file. And JSP is my requirement, so i have to do this on JSP only.

angrycat · October 25th, 2004, 06:58 AM

I dont think youll find one solution to this, I couldnt, but I did get images uploaded into a database.
First the form POSTED the data to a servlet.
This servlet put the data into a byte array named fileBytes:

byte fileBytes[]=new byte[27000];
System.arraycopy(tmpbuffer, 0, fileBytes, offset, length);

I then put the data into a byte array input stream. The number parameters are the start and end characters.

bin = new ByteArrayInputStream( fileBytes, 2, offset-2 );

I then put this data into a normal input stream:

InputStream is = bin;

Then used the following as part of a prepared statement:

pstmt.setBinaryStream( 5, is, (int)(len));

Its a bit of a game but it works.

angrycat · October 25th, 2004, 02:21 PM

Hello again, just remembered this JSP example, not sure if it will work first time as ive messed around with it. Found the basis of it on the Sun Java site. The person who posted it wanted to know why it would only work on their local machine, not the server. The answer is that this uses the GET method, so only passes the file path/name. This is ok on a local machine as the file can be found, but less useful when passed to the server.

This will allow you to get a test working which poulates a database, but you will need to use the info in my previous posts including the tutorial if you want to get it working on a client/server basis.

If you cant get this working look for original thread on Sun Java site.

<%@ page contentType="image/jpeg; chaoResult=iso-8859-1" language="java" %>
<%@ page session="false" %>
<%@ page import="java.sql.*" %>
<%@ page import="java.util.*" %>
<%@ page import="javax.servlet.*" %>
<%@ page import="javax.servlet.http.*" %>
<%@ page import="java.io.*" %>

<html>
<body>

<%
    File img= new File(request.getParameter("image"));

    String databaseDriver = "org.gjt.mm.mysql.Driver";
    Class.forName( databaseDriver );
    String databaseName = "jdbc:mysql://localhost/test";
    Connection con = null;
    try{
        con = DriverManager.getConnection(databaseName, "dBt","");
    //response.setContentType("image/jpeg");
        String str = "INSERT INTO images (id, image) VALUES ?,?)";
        PreparedStatement pstmt = con.prepareStatement(str);

pstmt.setString(1, "test");
InputStream is = new FileInputStream(img);
pstmt.setBinaryStream( 2, is, (int)(img.length()));
//set the Blob
pstmt.executeUpdate();
is.close();

   pstmt.close();
    pstmt = null;
    }

    finally {
        if (con != null )
        {
            con.close();
        }
    }

%>
</BODY>
</HTML>

Lamas · January 19th, 2005, 12:07 AM

I am also interested in this topic. but i think that topic is not the end of the story.

I would also like to know how to retrive the file from database.
Now, I know how to change the file into file stream and store in blob database, but how can I make use of it? like allow user to download or save it back into file or retrive it and do process base on it?

I am using mysql database and JSP to handle the request.

Thanks~~

angrycat · January 19th, 2005, 05:48 PM

It is not the end of the story!

This thread shows in a rough fashion how to get images out of a database and display them in a JSP page.

http://forum.java.sun.com/thread.jsp...hreadID=505366

Expanding on this you can manipulate the image, this link shows how to watermark and blend images. This is the best code I have ever found in a forum!!

http://forum.java.sun.com/thread.jsp...hreadID=505366

All you have to do is write a servlet that tie's it all together hehe.

rahulsaxena · January 21st, 2005, 04:33 AM

hey all,
please give me the sample JSP source code to upload file as object into database.

thanks,
rahul

bditt · January 22nd, 2005, 12:30 PM

Uhm....ever think of using the JSTL 2.0 sql taglib? I don't see why you couldn't use a <sql:update after a file was selected in a form....com'on guys, you don't need someone to hold your hand every step of the way. I'd personally use webwork2 and the interceptors to get files. http://www.opensymphony.com/webwork/...terceptor.html

Brian

angrycat · January 22nd, 2005, 09:41 PM

I have been using beans to perform sql transactions and return data to my jsp pages, not sure if this is the best approach, but as I will need to put the same program on different servers it seemed easier to keep it all in java as opposed to using jsp / jstl

Liked the link you posted, reckon Ill incorporate some of these methods into my servlet, thanks.