Java API for file upload JSP/Servlet by multipart/form-data

Make It Simpler by Object Oriented Programming

How to set the maximum file size by OOP MimeParser: Java API for file upload JSP/Servlet by multipart/form-data

Java API for file upload JSP/Servlet by multipart/form-data. It can set the maximum file size to be uploaded. If the user tries to upload the larger files, your JSP/Servlet can catch the exception.
This page describes how to set the maximum file size by OOP MimeParser.

This Java API can set the maximum width/height of the image file (JPEG, GIF or PNG). For details about this feature, please read another page.

Introduction of OOP MimeParser
API documentation of OOP MimeParser
README of OOP MimeParser
The simplest example for file upload Servlet/JSP : First step for file upload Servlet/JSP
The very simple example for file upload Servlet/JSP : How to specify the file name on the destination Servlet/JSP
The practical example, Photo Album by Servlet/JSP : How to create Photo Album by Servlet/JSP
Another example for how to upload files by Servlet/JSP : How to allocate the unique directory per user
Yet another example for how to upload files by Servlet/JSP : How to specify the file name by the departing CGI FORM
Example for how to send e-mails with file attachment : Get the binary contents of the uploaded files.

Restrict Content-Length (in bytes) of the HTTP request

To protect your JSP/Servlet against some kinds of denial-of-service attacks, all the parseXX( ) methods check the Content-Length of each HTTP request before processing the HTTP request. Please specify the max_request property in:

(docBase)/WEB-INF/classes/MimeParser.properties

If the Content-Length of the HTTP request is larger than this property, these methods will throw TooLargeBodyException soon, without reading any bytes of the request body.
The Content-Length consists of:

The size of the uploaded file
The size of the submitted text
The size of the boundary text, which is generated by the web browser

So, the maximum size of the Content-Length must be larger than the maximum size of the uploaded file. For example, if you'd like to set the maximum file size to 100 KB, the maximum Content-Length should be set to 150 KB or 200 KB. If the CGI FORM has many text input fields, it should be 200 KB larger (or more) than the maximum file size.
This property must be specified in bytes. For example, if you'd like to set the maximum Content-Length to 100 KB, this property will be 102400.

Restrict the size of the file to be uploaded

In usual, your Servlets/JSP needs to set the maximum file size to be uploaded. The default maximum size can be specified in the resource file. If 0 (zero) is specified, any size of files can be uploaded. The following 8 methods use this default maximum file size:

parseAndSave(HttpServletRequest req, String dir)
parseAndSave(HttpServletRequest req, String dir, Set mime)
parseAndSave(HttpServletRequest req, String ch, String dir)
parseAndSave(HttpServletRequest req, String ch, String dir, Set mime)
parseOnly(HttpServletRequest req)
parseOnly(HttpServletRequest req, Set mime)
parseOnly(HttpServletRequest req, String ch)
parseOnly(HttpServletRequest req, String ch, Set mime)

But, the default maximum file size can be overridden by max parameter of:

parseAndSave(HttpServletRequest req, String dir, int max)
parseAndSave(HttpServletRequest req, String dir, int max, Set mime)
parseAndSave(HttpServletRequest req, String ch, String dir, int max)
parseAndSave(HttpServletRequest req, String ch, String dir, int max, Set mime)
parseOnly(HttpServletRequest req, int max)
parseOnly(HttpServletRequest req, int max, Set mime)
parseOnly(HttpServletRequest req, String ch, int max)
parseOnly(HttpServletRequest req, String ch, int max, Set mime)

By these methods, you can set the different upper limits for each requests.

When the user tries to upload the larger files, all parseXXX(...) methods will throw:

TooLargeFileException

So, your Servlets/JSP can catch it and have a chance to display the appropriate message.

Caution!

All the APIs for Servlet/JSP introduced by this web site are now included in Bento framework:

Simpler than JSTL or Apache Struts
MVC framework by HTML
Input validation from CGI FORM
Easy user authentication
Easy localization (L10n)

To download the APIs and source code examples, please visit the web site of Bento framework.

Java and all Java-based trademarks and logos are trademarks or registered of Sun Microsystems, Inc. in the United States and other countries.

How to set the maximum file size by OOP MimeParser: Java API for file upload JSP/Servlet by multipart/form-data

Related Pages:

Restrict Content-Length (in bytes) of the HTTP request

Restrict the size of the file to be uploaded