File upload & Spring Security - spring-security

Question

Based on the Spring Security documentation, I setup a MultipartFileter as the following:
#Order(1)
public class SecurityWebAppInitializer
extends AbstractSecurityWebApplicationInitializer {
#Override
protected void beforeSpringSecurityFilterChain(ServletContext servletContext) {
insertFilters(servletContext, new MultipartFilter());
}
In a file upload form, I can see a CSRF input with a not-null value in a HTML file (see the code below).
<form method="POST" enctype="multipart/form-data" action="/upload">
File to upload: <input type="file" name="file" /><br />
Name: <input type="text" name="name" /><br /> <br />
<input type="submit" value="Upload" />
Press here to upload the file!
<input type="hidden" name="_csrf" value="df94be7d-675d-428c-89e5-2ebf0b473c42" />
</form>
After submitting the form, I get an error as
HTTP Status 403 - Invalid CSRF Token 'null' was found on the request parameter '_csrf' or header 'X-CSRF-TOKEN'.
type Status report
message Invalid CSRF Token 'null' was found on the request parameter '_csrf' or header 'X-CSRF-TOKEN'.
description Access to the specified resource has been forbidden.
What is missing here?

Answer 1

This problem is resolved after changing the Java configuration of the application. The followings are those changes.
In AbstractAnnotationConfigDispatcherServletInitializer class, I add the MultipartFilter in the getServletFilters method and set the MultipartConfig with a MultipartConfigElement in customizeRegistration(ServletRegistration.Dynamic registration) method. A MutlipartConfigElement originally defined in WebMvcConfigurerAdapter class is removed. And a MultipartResolver defined in the class is unchanged.
The Java configuration was set up based on the original XML configuration of the application. The approach doesn't always work based on this case.