spring - Spring-MVC-Java ベースの構成: getOutputStream() は、この応答に対して既に呼び出されています

Question

Java ベースの構成で Spring 3 を使用しています。

Excelシートをユーザーにエクスポートするモジュールがあります（つまり、シートをユーザーにダウンロードします）

ログで次の例外が発生しました....しかし、正常にエクスポートされます：

java.lang.IllegalStateException: getOutputStream() は、org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade. java:214) で javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:105) で javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:105) で org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate (FreeMarkerView.java:366) org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283) org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java) :233) org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167) で org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:262) で org.springframework.web org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:927) の .servlet.DispatcherServlet.render(DispatcherServlet.java:1157) org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:827) ) org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:882) で org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:778) で javax.servlet.http.HttpServlet.service( HttpServlet.java:621) で javax.servlet.http.HttpServlet.service(HttpServlet.java:728) で org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305) で org.apache.catalina.core.ApplicationFilterChain.doFilter (ApplicationFilterChain.java:210) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:311) で org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:116) ) org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:83) で org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323) org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323) で org.springframework.security で org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113) で.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:101) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)doFilter(SessionManagementFilter.java:101) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)doFilter(SessionManagementFilter.java:101) at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:323)

調査の結果、getOutputStream() メソッドは応答に対して 1 回しか呼び出せないことがわかりました。ただし、ユーザーが次のようにシートをエクスポートする必要があるたびに呼び出します。

public void exportExcel(HttpServletResponse response) throws Exception {

    response.setContentType("application/vnd.ms-excel");

    response.setHeader("Content-disposition", "attachment;filename=" + sheetName + "");


    ByteArrayOutputStream excelFileByteArrayOutputStream =

    excelFileByteArrayOutputStream.writeTo(response.getOutputStream());
    excelFileByteArrayOutputStream.flush();
    response.flushBuffer();
    excelFileByteArrayOutputStream.close();
  }

フリーマーカー構成:

@Bean
  public FreeMarkerViewResolver viewResolver() {
    FreeMarkerViewResolver freeMarkerViewResolver = new FreeMarkerViewResolver();
    freeMarkerViewResolver.setCache(true);
    freeMarkerViewResolver.setPrefix("");
    freeMarkerViewResolver.setSuffix(".ftl");
    return freeMarkerViewResolver;
  }

  @Bean
  public FreeMarkerConfigurer freemarkerConfig() {
    FreeMarkerConfigurer freeMarkerConfigurer = new FreeMarkerConfigurer();
    freeMarkerConfigurer.setTemplateLoaderPath("/WEB-INF/freemarker/");
    Properties settings = new Properties();
    settings.setProperty("number_format", "0.######");
    freeMarkerConfigurer.setFreemarkerSettings(settings);
    Map variables = new java.util.HashMap<String, Object>();

    variables.put("xml_escape", new XmlEscape());
    freeMarkerConfigurer.setFreemarkerVariables(variables);
    return freeMarkerConfigurer;
  }

@Controlle ...シートがエクスポートされた後、指定したようにホームページにリダイレクトされることはありません：

  @RequestMapping(value = "/smth", method = RequestMethod.GET)
  public ModelAndView exportSheet(HttpServletResponse response,
                                                           Bean aBean,
                                                           BindingResult result) throws Exception {

//Some Code
    return new ModelAndView("/home");
  }

私の WebApplicationInitializer:

public class SpringWebApplicationInitializer implements WebApplicationInitializer {

  @Override
  public void onStartup(final ServletContext servletContext) throws ServletException {

    // Create the 'root' Spring application context
    AnnotationConfigWebApplicationContext rootContext = new AnnotationConfigWebApplicationContext();
    rootContext.register(WebConfiguration.class);

    // Manage the lifecycle of the root application context
    servletContext.addListener(new ContextLoaderListener(rootContext));

    // Create the dispatcher servlet's Spring application context
    AnnotationConfigWebApplicationContext dispatcherContext = new AnnotationConfigWebApplicationContext();
    dispatcherContext.register(DispatcherConfiguration.class);

    // Register and map the dispatcher servlet
    ServletRegistration.Dynamic dispatcher =
      servletContext.addServlet("dispatcher", new DispatcherServlet(dispatcherContext));
    dispatcher.setLoadOnStartup(1);
    dispatcher.addMapping("/");

    // Register Spring Security Filter
    DelegatingFilterProxy securityFilter = new DelegatingFilterProxy();
    FilterRegistration.Dynamic securityFilterRegistration =
      servletContext.addFilter("springSecurityFilterChain", DelegatingFilterProxy.class);
    securityFilterRegistration.addMappingForUrlPatterns(null, false, "/*");
  }


}

この問題をくすぐる方法を教えてください。