This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Framework 6.1.14!

Multipart Resolver

MultipartResolver from the org.springframework.web.multipart package is a strategy for parsing multipart requests including file uploads. There is a container-based StandardServletMultipartResolver implementation for Servlet multipart request parsing. Note that the outdated CommonsMultipartResolver based on Apache Commons FileUpload is not available anymore, as of Spring Framework 6.0 with its new Servlet 5.0+ baseline.

To enable multipart handling, you need to declare a MultipartResolver bean in your DispatcherServlet Spring configuration with a name of multipartResolver. The DispatcherServlet detects it and applies it to the incoming request. When a POST with a content type of multipart/form-data is received, the resolver parses the content wraps the current HttpServletRequest as a MultipartHttpServletRequest to provide access to resolved files in addition to exposing parts as request parameters.

Servlet Multipart Parsing

Servlet multipart parsing needs to be enabled through Servlet container configuration. To do so:

  • In Java, set a MultipartConfigElement on the Servlet registration.

  • In web.xml, add a "<multipart-config>" section to the servlet declaration.

The following example shows how to set a MultipartConfigElement on the Servlet registration:

  • Java

  • Kotlin

public class AppInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

	// ...

	@Override
	protected void customizeRegistration(ServletRegistration.Dynamic registration) {

		// Optionally also set maxFileSize, maxRequestSize, fileSizeThreshold
		registration.setMultipartConfig(new MultipartConfigElement("/tmp"));
	}

}
class AppInitializer : AbstractAnnotationConfigDispatcherServletInitializer() {

	// ...

	override fun customizeRegistration(registration: ServletRegistration.Dynamic) {

		// Optionally also set maxFileSize, maxRequestSize, fileSizeThreshold
		registration.setMultipartConfig(MultipartConfigElement("/tmp"))
	}

}

Once the Servlet multipart configuration is in place, you can add a bean of type StandardServletMultipartResolver with a name of multipartResolver.

This resolver variant uses your Servlet container’s multipart parser as-is, potentially exposing the application to container implementation differences. By default, it will try to parse any multipart/ content type with any HTTP method but this may not be supported across all Servlet containers. See the StandardServletMultipartResolver javadoc for details and configuration options.