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

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How to specify the charset 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. This Java API makes your JSP/Servlet ready for 2 bytes characters (Japanese Shift_JIS, Chinese BIG5, Chinese GB2312 or Russian KOI8-R).
For i18n (Internationalization) of your Servlets/JSP, the text parameters in the CGI FORM must be decoded by the correct charset. For example, if the text parameter is encoded by Japanese Shift_JIS and sent as the HTTP request of multipart/form-data, your JSP/Servlet must decode it also by Japanese Shift_JIS. This page describes how to specify the charset by OOP MimeParser.

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.

By which charset to decode the text parameter

The text parameter includes:

INPUT with the type of TEXT
INPUT with the type of HIDDEN
INPUT with the type of PASSWORD
INPUT with the type of CHECKBOX
INPUT with the type of RADIO
INPUT with the type of SUBMIT
SELECT
TEXTAREA

To make your Servlet truly internationalization (i18n) ready, your Servlet needs to decode the text parameter by the charset same as it is encoded. For example, if the text parameters are encoded by Japanese Shift_JIS, these text parameters need to be decoded by Japanese Shif_JIS. This is also true for Chinese BIG5, Chinese GB2312 or Russian KOI8-R.
By MimePaser, you can specify the charset in various ways.

The default charset is specified in the property resource file. This default charset is used by the following 8 methods:

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

This default charset can be overridden within your Servlet/JSP by the second parameter of:

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

But, the charset specified by these method can also be overriden. In case that TEXT INPUT, SELECTION or HIDDEN INPUT whose name is charset is found in the request, its value will be used. For example, the FORM below includes the HIDDEN INPUT whose name is charset. On the destination Servlet/JSP, MimeParser picks up the value of this HIDDEN INPUT and decodes the rest of the text parameters by Shift_JIS. Form with charset

Moreover, if the charset header is set by the browser, it will take precedence all of them. This is because the charset sent from the browser is the most reliable. But the browsers in the real world does not set charset header.

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 specify the charset by OOP MimeParser: Java API for file upload JSP/Servlet by multipart/form-data

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By which charset to decode the text parameter