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需要 Servlet 3.0 的AsyncContext ，因此请检查您的web.xml和 WebLogic 文档，以确保您正确执行了所有操作，以便在 WebLogic 下为您的应用程序启用 Servlet 3.0。

Answer 2

You are getting this exception while server returning an error to browser. Do you have log statements in catch blocks? If it is missing, logging the exception before returning the response may be helpful to understand the real issue. Root cause of the error may be a library conflict or enabling jpa2.0 instead of jpa2.1.

catch (Exception e) {
        log.error("Error, ", e);
        result.setResult(ResponseEntity.badRequest().build());
        // ...
}