request.getParameterNames() is empty after setting the form's enctype to "multipart/form-data"

Question

Im developing a simple file upload using JSP, everything works fine until I set the form's enctype to "multipart/form-data", request.getParameterNames() is returning empty. Any idea?

Here's my code:

upload.jsp

<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>File Upload</title>
    </head>
    <body>
        <form method="POST" action="login.jsp" enctype="multipart/form-data">
            <input type="text" name="name" placeholder="File Name"></input>
            <br>
            <input type="file" name="file" id="file"></input>
            <br><br>
            <input type="submit" name="submit" id="submit" value="Submit"></input>
        </form>
    </body>
    </html>

login.jsp

<%@page import="java.util.Enumeration"%>
<%@page import="java.io.InputStream"%>
<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>JSP Page</title>
    </head>
    <body>
        <%
            Enumeration params = request.getParameterNames();
            boolean empty = true;
            while(params.hasMoreElements()){
                String param = params.nextElement().toString();
                out.println(param);
                empty = true;
            }
            if(empty) out.println("No parameters received!");
        %>
    </body>
</html>

Another food for read: http://stackoverflow.com/questions/3177733/how-to-avoid-java-code-in-jsp-files/ — BalusC, Apr 28 '15 at 16:25

score 1 · Answer 1 · edited May 23 '17 at 11:58

1

please see here: Convenient way to parse incoming multipart/form-data parameters in a Servlet

multipart is parsed differently on the servlet side. On servlet spec 3 you need to call 'getParts()', on older specs you might want to consider a 3rd party such as Apache FileUpload .

edited May 23 '17 at 11:58

Community

1
1

answered Apr 28 '15 at 05:17

Pelit Mamani

2,321
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If you found a duplicate answer, why don't you just flag/vote for close as duplicate? – BalusC Apr 28 '15 at 16:24
Frankly, I wasn't aware of this option. Sorry. – Pelit Mamani Apr 28 '15 at 19:35

score 1 · Answer 2 · edited May 23 '17 at 12:22

1

This issue is because of enctype="multipart/form-data" so alternatively you can use @MultipartConfig annotation (available after javaee6 and servlet 3.0) or commans-fileupload as suggested in the below posts:

request.getParameter on a submit button giving null value

Get parameter when multipart request in JSP

edited May 23 '17 at 12:22

Community

1
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answered Apr 28 '15 at 05:25

Shivang Agarwal

1,825
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Im using JSP, I dont have a servlet. Where do you insert @MultipartConfig in JSP? – Ethyl Casin Apr 28 '15 at 05:34
What kind of project do you have, if you don't have a Servlet? – Shota Apr 28 '15 at 07:32
You can also use MultipartFormDataRequest which will be more easy and one more thing its good to use servlet for business logic. – Shivang Agarwal Apr 28 '15 at 12:27
If you found a duplicate answer, why don't you just flag/vote for close as duplicate? – BalusC Apr 28 '15 at 16:24
because i don't have that much reputation like you ... – Shivang Agarwal Apr 28 '15 at 17:36

request.getParameterNames() is empty after setting the form's enctype to "multipart/form-data"

2 Answers2