Null is passed into doFilter() as the request parameter when the form's enctype="multipart/formdata"

[Paweł Ryszawa]

Hi!

I encountered the following problem:

I created a filter to wrap multipart requests. It's aim is to help override getParameter-like methods in order to translate parts-like parameters to "ordinary" parameters, i.e.:

@WebFilter(urlPatterns = { "/*" })

public class MultipartFormDataFilter implements Filter {

    @Override

    public void init(FilterConfig fc) throws ServletException {

        //

    }

    @Override

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {

        HttpServletRequest httpRequest = (HttpServletRequest)request;

        MultipartFormDataRequest multipartRequest = new MultipartFormDataRequest(httpRequest);

        chain.doFilter(multipartRequest, response);

    }

    @Override

    public void destroy() {

        //

    }

}

MultipartFormDataRequest is a simple http servlet request wrapper that overrides getParameter(String), getParameterValues(String), getParameterNames() and getParameterMap() methods.Those methods should return parameters discovered in the request's (so called) parts. The overall mechanism is sucessfully tested with glassfish. However, JBoss "fails" (while glassfish do not) when the form has enctype="multipart/form-data".

I really need enctype="multipart/form-data" in my forms, since some business needs require file uploading.

Stack trace starts with:

17:19:18,281 ERROR [org.apache.catalina.core.ContainerBase.[jboss.web].[localhost].[/simik_gen].[FacesServlet]] Servlet.service() for servlet FacesServlet threw exception: java.lang.NullPointerException

        at org.apache.catalina.connector.Request.getParts(Request.java:3233) [:6.0.0.Final]

        at org.apache.catalina.connector.RequestFacade.getParts(RequestFacade.java:1112) [:6.0.0.Final]

Does JBoss have a bug? Am I doing something wrong?

Regards,

Paweł

[Paweł Ryszawa]

Sorry for the mistake in the title: request is not null, of course - it is request.getParts() which throws NullPointerException.

[jaikiran pai]

Post the entire exception stacktrace and also the code in MultipartFormDataRequest.

[Paweł Ryszawa]

Some research in Internet shed leight to the issue. JSF implementation servlets (Mojarra 2.0.x) are not decorated with @MultipartConfig annotation. Although GlassFish v3 cope with it assumig some default config, JBoss's jbossweb component - do not. JbossWeb-3.0.0.Beta8 patches the problem by hiding the exception - but this does not resolve the the core problem.

I have dug into the source code of JBossWeb and I have done the following change:

In "org.apache.catalina.connector.Request" class - method "protected void parseMultipart()":

I have changed

if (config == null) {

  return;

}

to

if (config == null) {

  config = new Multipart();

  config.setLocation(null);

  config.setFileSizeThreshold(Integer.MAX_VALUE);

  config.setMaxFileSize(Long.MAX_VALUE);

  config.setMaxRequestSize(Long.MAX_VALUE);

}

Having the above compiled ("jbossweb.jar") and dropped into the jboss, my appliaction started to work correctly.

The old version caused property parts to remain null, hence the following method:

public Part getPart(String name) throws IOException, ServletException {

  if (parts == null) {

      parseMultipart();

  }

  return parts.get(name);

}

after returning from parseMultipart() used to throw a NullPointException.

BTW: Beta8 patch did the "parts" to become en ampty map in this situation. This, of course, did not resolve the problem of getting out the parameters send by client browser in multipart/form-data format.

Regards,

P.S. Please be aware of the issue. GlassFish v3 and Tomcat 7.0.7 have already resolved this. IMHO some changes to the servlet specification should be introduced - v. 3.0 apparently lacks of something...

[jaikiran pai]

Moved to JBossWeb forum.

[Remy Maucherat]

No multipart parsing will be done unless the associated Servlet has a multipart config, as per the specification.

[Paweł Ryszawa]

Yes, I understand the strict compliance with the specification.

Nevertheless, Glassfish's and Tomcat's developers found the specification somehow incomlete and put their own workaround for the issue. I think, JBoss AS users would really appreciate if You did a similar improvement. Apache Tomcat 7.0.7+, for instance, has a parameter to activate its workaround, so out-of-specs behavior is not default. GlassFish v.3 seems to workaround it by default.

Moreover, the specifiaction does not concern the filters in the area of multiparts. These are processed out of the target servlet, so no @MultipartConfig can be assigned a the moment.

Regards,

[Remy Maucherat]

Yes, you already mentioned that earlier.

Update: The patch for JBWEB-187 is now committed in the web branch that is included in AS 6.

[Paweł Ryszawa]

JBWEB-187 fix the NPE problem. It still does not resolve the problem of retrieving data from parts (it return an empty map insetad of null map, which caused the NPE).

Regards,

[Antoine ROUAZE]

Hello,

I have the same problem, but it works perfectly with Glassfish. I can well recover the Parts with the method getParts.

I wanted to know if you find a solution for JBoss?

Best regards,

Antoine ROUAZE

[Jean-Frederic Clere]

Add a @MultipartConfig in your servlet.

[Antoine ROUAZE]

But without a Servlet is  possible?

[Jean-Frederic Clere]

You need a Sevlet probably what you are doing in the filter should be in a servlet.