request getParameter is always null when using enctype=“multipart/form-data”

Question

I am performing validation of inputted data such as email, password, name, etc. But I am already stuck on the first stage of validation which is to check if User entered not

Answer 1

Unless you're planning to use your form for uploading a file, you don't need to specify the encoding type of "multipart/form-data".

<form method="POST" action="signup">
    <input type="text" name="email" placeholder="tonystark@mail.com">
     <input type="submit" value="Submit">
</form>

The last paragraph in your link states:

"When using enctype="multipart/form-data", all parameters are encoded in the request body. That means that request.getParameter(...) will return null for all posted parameters then."

Input type: email

Email is an html5 input type. How To Use The New Email, URL, and Telephone Input Types.

Answer 2

Since it is a multipart/form-data (usually used for the puropose of uploading one/more file(s)) form the request.getParameter() method will always return null.

You can try

 <form method="POST" action="signup" enctype="application/x-www-form-urlencoded">

Or completely remove the enctype parameter.

Some references in another SO question.

How to upload files to server using JSP/Servlet?