GraphQL multipart requests in DXP 7.4

Issue

Trying to upload image to DXP 7.4 via GraphQL API (createDocumentFolderDocument method).
This approach seems not be valid after DXP 7.2:
https://help.liferay.com/hc/en-us/articles/360039026272-Multipart-Requests
The approach used in DXP 7.2 now produces the following error:

ERROR [http-nio-8080-exec-7][AbstractGraphQLHttpServlet:86] Error executing GraphQL request!
java.lang.IllegalStateException: getInputStream() has already been called for this request
at org.apache.catalina.connector.Request.getReader(Request.java:1206) ~[catalina.jar:9.0.75]
at org.apache.catalina.connector.RequestFacade.getReader(RequestFacade.java:392) ~[catalina.jar:9.0.75]
at javax.servlet.ServletRequestWrapper.getReader(ServletRequestWrapper.java:213) ~[servlet-api.jar:4.0.FR]
at javax.servlet.ServletRequestWrapper.getReader(ServletRequestWrapper.java:213) ~[servlet-api.jar:4.0.FR]
at javax.servlet.ServletRequestWrapper.getReader(ServletRequestWrapper.java:213) ~[servlet-api.jar:4.0.FR]
at javax.servlet.ServletRequestWrapper.getReader(ServletRequestWrapper.java:213) ~[servlet-api.jar:4.0.FR]
at graphql.kickstart.servlet.GraphQLPostInvocationInputParser.getGraphQLInvocationInput(GraphQLPostInvocationInputParser.java:35) ~[graphql-java-servlet-12.0.0.jar:?]
at graphql.kickstart.servlet.HttpRequestHandlerImpl.handle(HttpRequestHandlerImpl.java:42) ~[graphql-java-servlet-12.0.0.jar:?]
at graphql.kickstart.servlet.AbstractGraphQLHttpServlet.doRequest(AbstractGraphQLHttpServlet.java:84) [graphql-java-servlet-12.0.0.jar:?]
at graphql.kickstart.servlet.AbstractGraphQLHttpServlet.doPost(AbstractGraphQLHttpServlet.java:79) [graphql-java-servlet-12.0.0.jar:?]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:555) [servlet-api.jar:4.0.FR]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:623) [servlet-api.jar:4.0.FR]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:?]
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:?]
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:?]
at java.lang.reflect.Method.invoke(Method.java:566) ~[?:?]
at com.liferay.portal.vulcan.internal.graphql.servlet.GraphQLServletExtender$10.invoke(GraphQLServletExtender.java:654) [bundleFile:?]
at com.sun.proxy.$Proxy470.service(Unknown Source) [?:?]
at org.eclipse.equinox.http.servlet.internal.registration.EndpointRegistration.service(EndpointRegistration.java:153) [bundleFile:?]

Environment

DXP 7.4

Resolution

The GraphQL API (createDocumentFolderDocument method) is available in 7.4, and it works as described in the documentation.
The steps that are required to be made in order to execute the mutation successfully are the following:

First, locate the Liferay application’s web.xml file, in our case, the shielded-container-web.xml file found inside the following path in case the container used is tomcat-9.0.83: bundles/tomcat-9.0.83/webapps/ROOT/WEB-INF/shielded-container-web.xml
Secondly, modify the servlet configuration of the "Module Framework Servlet" found within the shielded-container-web.xml file. This name will be contained between the <servlet-name></servlet-name> tags. The full "Module Framework Servlet" configuration should look something like:

<servlet> 
  <servlet-name>Module Framework Servlet</servlet-name> 
  <servlet-class>com.liferay.portal.module.framework.ModuleFrameworkServletAdapter</servlet-class> 
  <load-on-startup>1</load-on-startup> 
  <async-supported>true</async-supported> 
  <multipart-config> 
    <location>/tmp</location> 
    <max-file-size>20848820</max-file-size> 
    <max-request-size>418018841</max-request-size> 
    <file-size-threshold>1048576</file-size-threshold> 
  </multipart-config> 
</servlet>

Once modified and saved, restart the portal.
After restarting, execute the mutation query for an existing document folder with an existing document found in your computer. Here's a CURL to achieve that:

curl 'http://localhost:8080/o/graphql' \ 
-u 'test@liferay.com:test' \ 
-F operations='{ 
   "query":"mutation($files: [Upload]) {createDocumentFolderDocument(multipartBody: $files, documentFolderId: \"33449\") {id}}", 
   "variables":{ 
      "files":[ 
         null 
      ] 
   } 
}' \ 
-F map='{ "0": ["variables.files.0"]}' \ 
-F 0=@"file.txt"

NOTE: You’d need to modify the authentication, documentFolderId and file path to your case in order to make the request work.