DeferredResult causes an Exception in Weblogic

Question

I have a Java 7 Spring Boot (1.5.4) RESTfull service with an endpoint that returns a DeferredResult:

@RequestMapping(value = "/download/{templateName:.+}")
public DeferredResult<ResponseEntity> download(@PathVariable final String templateName,
                                               @RequestParam final Map<String, Object> args) {
    final DeferredResult<ResponseEntity> result = new DeferredResult<>();
    try {
        // it returns a RxJava Observable
        final ReportService reportService = getReportService(templateName);
        reportService.process(templateName, args).subscribe(new Consumer<byte[]>() {
            public void accept(byte[] bytes) throws Exception {
                HttpHeaders header = new HttpHeaders();
                header.setContentType(new MediaType("application", MEDIA_TYPE_SPREADSHEET));
                header.setContentDispositionFormData("attachment", templateName);

                InputStreamResource resource = new InputStreamResource(new ByteArrayInputStream(bytes));
                result.setResult(ResponseEntity.ok().headers(header).body(resource));
            }
        }, new Consumer<Throwable>() {
            public void accept(Throwable e) throws Exception {
                result.setResult(ResponseEntity.badRequest().build());
                // ...
            }
        });
    } catch (Exception e) {
        result.setResult(ResponseEntity.badRequest().build());
        // ...
    }

    return result;
}

It works fine if I use the Spring Boot embedded server or deploy it to Tomcat. But if I deploy it to the Weblogic (v. 12.2.1.2.0), I got the following error:

java.lang.NullPointerException
at weblogic.servlet.internal.ServletResponseImpl.sendContentError(ServletResponseImpl.java:727)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:779)
at weblogic.servlet.internal.ServletResponseImpl.sendError(ServletResponseImpl.java:702)
at org.springframework.boot.web.support.ErrorPageFilter$ErrorWrapperResponse.flushBuffer(ErrorPageFilter.java:315)
at weblogic.servlet.internal.RequestDispatcherImpl.forward(RequestDispatcherImpl.java:305)
at org.springframework.web.servlet.view.InternalResourceView.renderMergedOutputModel(InternalResourceView.java:168)
at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:303)
at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1286)
at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1041)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:984)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:286)
at weblogic.servlet.internal.StubSecurityHelper$ServletServiceAction.run(StubSecurityHelper.java:260)
at weblogic.servlet.internal.StubSecurityHelper.invokeServlet(StubSecurityHelper.java:137)
at weblogic.servlet.internal.ServletStubImpl.execute(ServletStubImpl.java:350)
at weblogic.servlet.internal.TailFilter.doFilter(TailFilter.java:25)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at org.springframework.boot.web.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:115)
at org.springframework.boot.web.support.ErrorPageFilter.access$000(ErrorPageFilter.java:59)
at org.springframework.boot.web.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:90)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.springframework.boot.web.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:108)
at weblogic.servlet.internal.FilterChainImpl.doFilter(FilterChainImpl.java:78)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.wrapRun(WebAppServletContext.java:3683)
at weblogic.servlet.internal.WebAppServletContext$ServletInvocationAction.run(WebAppServletContext.java:3649)
at weblogic.security.acl.internal.AuthenticatedSubject.doAs(AuthenticatedSubject.java:326)
at weblogic.security.service.SecurityManager.runAsForUserCode(SecurityManager.java:197)
at weblogic.servlet.provider.WlsSecurityProvider.runAsForUserCode(WlsSecurityProvider.java:203)
at weblogic.servlet.provider.WlsSubjectHandle.run(WlsSubjectHandle.java:71)
at weblogic.servlet.internal.WebAppServletContext.doSecuredExecute(WebAppServletContext.java:2433)
at weblogic.servlet.internal.WebAppServletContext.securedExecute(WebAppServletContext.java:2281)
at weblogic.servlet.internal.WebAppServletContext.execute(WebAppServletContext.java:2259)
at weblogic.servlet.internal.ServletRequestImpl.runInternal(ServletRequestImpl.java:1691)
at weblogic.servlet.internal.ServletRequestImpl.run(ServletRequestImpl.java:1651)
at weblogic.servlet.provider.ContainerSupportProviderImpl$WlsRequestExecutor.run(ContainerSupportProviderImpl.java:270)
at weblogic.invocation.ComponentInvocationContextManager._runAs(ComponentInvocationContextManager.java:348)
at weblogic.invocation.ComponentInvocationContextManager.runAs(ComponentInvocationContextManager.java:333)
at weblogic.work.LivePartitionUtility.doRunWorkUnderContext(LivePartitionUtility.java:54)
at weblogic.work.PartitionUtility.runWorkUnderContext(PartitionUtility.java:41)
at weblogic.work.SelfTuningWorkManagerImpl.runWorkUnderContext(SelfTuningWorkManagerImpl.java:640)
at weblogic.work.ExecuteThread.execute(ExecuteThread.java:406)
at weblogic.work.ExecuteThread.run(ExecuteThread.java:346)

I can still download my file from the service, but I always get this error. Working synchronously solves the problem, but it should be async. Do you know what can cause such an error and/or how one can avoid it?

Answer 1

DeferredResult needs AsyncContext of Servlet 3.0, so checks your web.xml and WebLogic documentation to be sure you do everything correctly to enable Servlet 3.0 for your application under WebLogic.