Question

我在Spring 3中使用基于Java的配置。

我有一个模块可以将Excel工作表导出到用户（即将工作表下载到用户）

我在日志中遇到以下异常......但导出正常：

java.lang.IllegalStateException：getOutputStream（）已经存在呼吁这个回应在org.apache.catalina.connector.Response.getWriter（Response.java:639）在org.apache.catalina.connector.ResponseFacade.getWriter（ResponseFacade.java:214）在javax.servlet.ServletResponseWrapper.getWriter（ServletResponseWrapper.java:105）在javax.servlet.ServletResponseWrapper.getWriter（ServletResponseWrapper.java:105）在org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate（FreeMarkerView.java:366）在org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender（FreeMarkerView.java:283）在org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel（FreeMarkerView.java:233）在org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel（AbstractTemplateView.java:167）在org.springframework.web.servlet.view.AbstractView.render（AbstractView.java:262）在org.springframework.web.servlet.DispatcherServlet.render（DispatcherServlet.java:1157）在org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:927）在org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:827）在org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:882）在org.springframework.web.servlet.FrameworkServlet.doGet（FrameworkServlet.java:778）在javax.servlet.http.HttpServlet.service（HttpServlet.java:621）在javax.servlet.http.HttpServlet.service（HttpServlet.java:728）在org.apache.catalina.core.ApplicationFilterChain.internalDoFilter（ApplicationFilterChain.java:305）在org.apache.catalina.core.ApplicationFilterChain.doFilter（ApplicationFilterChain.java:210）在org.springframework.security.web.FilterChainProxy $ VirtualFilterChain.doFilter（FilterChainProxy.java:311）在org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke（FilterSecurityInterceptor.java:116）在org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter（FilterSecurityInterceptor.java:83）在org.springframework.security.web.FilterChainProxy $ VirtualFilterChain.doFilter（FilterChainProxy.java:323）在org.springframework.security.web.access.ExceptionTranslationFilter.doFilter（ExceptionTranslationFilter.java:113）在org.springframework.security.web.FilterChainProxy $ VirtualFilterChain.doFilter（FilterChainProxy.java:323）在org.springframework.security.web.session.SessionManagementFilter.doFilter（SessionManagementFilter.java:101）在org.springframework.security.web.FilterChainProxy $ VirtualFilterChain.doFilter（FilterChainProxy.java:323）

经过调查，我发现getOutputStream（）方法只能在响应上调用一次。但是，每次用户需要导出工作表时，我都会调用它：

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();
  }

Freemarker配置：

@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 ...导出工作表后，它永远不会像我指定的那样重定向到主页：

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

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

我的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, "/*");
  }


}

任何想法如何解决这个问题！

基于Spring-MVC-Java的配置：已经为此响应调用了getOutputStream（）

0 个答案: