Sample for a servlet handling file upload?

I'm pretty new to Java and Servlets (but "old" in HTML/HTTP Servers etc). I need a servlet, that is able to process a HTTP Post that includes a multipart MIME content a.k.a File-Upload with multiple files.
What I want to do:
- check for a "legal" file extension
(e.g. only loading gif, jpg, png)
- check for the sizes of the files
(e.g. only upload up to 20 kb)
- save the file to disk.
The problems i'm clueless about:
- how to find the files within the request body
- how to determine the size upfront
- how to decode the files back to the binary format
THX

stw

Use multipart servlet .. for example you can look at the following package ...
com.oreilly.servlet
For more info visit the following link
http://www.servlets.com/cos/index.html

Stephan, I'm using jspsmartupload to achieve all the things you want :-).
check www.jspsmart.com
if you need any help drop me an email..
britt50423@yahoo.com
good luck

On the client side, the client's browser must support form-based upload. Something like:
<FORM ENCTYPE="multipart/form-data"
method="POST" action="/theservlet">
<INPUT TYPE="file" NAME="me.jpg">
<INPUT TYPE="submit" VALUE="upload">
</FORM>
Then in order to code a servlet being able of processing the POST data to extract the encoded file you can take a look to the required format in the RFC-1867. ( http://www.ietf.org/rfc/rfc1867.txt ).
If you prefer to use a library to do it instead of code your own servlet, here you have a number of libraries available:
.-Jason Hunter's MultipartRequest at http://www.servlets.com
.-CParseRFC1867 (available from http://www.servletcentral.com).
.-There are MIME-parsing routines in JavaMail
.-www.JSPSmart.com has a free set of JSP for uploading and downloading files.

-HTH

Hi Shubhrajiit (and all the others),
thx for the info. I have the problem, that I cannont deploy any Java packages to the production server (that is a political, not a technical restriction). Could I extract the class(es) needed from the oreilly package? What classes would that be?

Originally posted by Shubhrajit Chatterjee:
for example you can look at the following package ...
com.oreilly.servlet

I have the problem, that I cannont deploy any Java packages to the production server (that is a political, not a technical restriction). Could I extract the class(es) needed from the oreilly package? What classes would that be?

dear stephan
i think u must have dwnloaded the com.oreilly... package. u must be having a directory structure like com->oreilly->servlet...now on the server u can make a similar directory structure inside the servlet directory...
hope this helps...it did for me...still if that doesnt..just revert...
malhar
(A

doesn't cost anything...keep smiling)

Stephan,

You've got an interesting problem. By that I mean: If you can't deploy any java packages on your production server, how do the Mordacs in your organization expect you to deploy your own application?

(Mordac: Preventer of Information Services)

Anyways... If you're able to deploy WAR files (your application) then you can utilize the WEB-INF/lib directory within this package to 'hide' the cos.jar file. It would stil be a 'java package', but it would be 'part' of your application. You can make the political case that it won't work without it.

Hi there,
thx for the help. I need to elaborate a little. The server I'm deploying to is a Lotus Domino R5. It has only a JRE 1.1.8 and no real deployment mechanism for all the nice J2EE stuff. So I can put small servlets in the servlet directory, that's it more or less.
So how would I go with the com.oreilly.servlet. I asume the book has the source-code. I probably could migrate the one function I need (and it's depencencies) into my source file. However I'm a VERY GREEN Java Horn

, so how to go?

If you think education is expensive - try ignorance!