Spring Boot 启用 <async-supported> 就像在 web.xml 中一样

Question

我的 Spring Boot 配置有问题。我在一些应该使用套接字的移动设备上遇到了异常：

java.lang.IllegalArgumentException: Async support must be enabled on a servlet and for all filters involved in async request processing. This is done in Java code using the Servlet API or by adding "<async-supported>true</async-supported>" to servlet and filter declarations in web.xml. Also you must use a Servlet 3.0+ container
    at org.springframework.util.Assert.isTrue(Assert.java:65)
    at org.springframework.http.server.ServletServerHttpAsyncRequestControl.<init>(ServletServerHttpAsyncRequestControl.java:59)
    at org.springframework.http.server.ServletServerHttpRequest.getAsyncRequestControl(ServletServerHttpRequest.java:202)
    at org.springframework.web.socket.sockjs.transport.session.AbstractHttpSockJsSession.handleInitialRequest(AbstractHttpSockJsSession.java:202)
    at org.springframework.web.socket.sockjs.transport.handler.AbstractHttpSendingTransportHandler.handleRequestInternal(AbstractHttpSendingTransportHandler.java:66)
    at org.springframework.web.socket.sockjs.transport.handler.AbstractHttpSendingTransportHandler.handleRequest(AbstractHttpSendingTransportHandler.java:58)
    at org.springframework.web.socket.sockjs.transport.TransportHandlingSockJsService.handleTransportRequest(TransportHandlingSockJsService.java:254)
    at org.springframework.web.socket.sockjs.support.AbstractSockJsService.handleRequest(AbstractSockJsService.java:322)
    at org.springframework.web.socket.sockjs.support.SockJsHttpRequestHandler.handleRequest(SockJsHttpRequestHandler.java:88)
    at org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter.handle(HttpRequestHandlerAdapter.java:51)
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:938)
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:870)
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:863)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:646)
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    ...

正如我从异常中看到的，我必须通过在 web.xml 文件中添加 true 来启用异步处理。但这是问题所在，因为我没有它——我们的项目使用 Spring Boot。

有没有办法在 Spring Boot 中提供相同的功能？

Answer 1

我的解决方案：

@WebFilter(value = {"/subscriberinfo/query/single/*"})
public class ...Filter{
} 

到

@WebFilter(value = {"/subscriberinfo/query/single/*"}, asyncSupported = true)
public class ...Filter{
} 

Answer 2

即使我迟到了，我也会为后代发布我的工作解决方案。

我遇到了同样的问题并尝试了@Artem Bilan 建议的解决方案。但是在调试代码后，我发现servletRegistrationBean.isAsyncSupported()默认是true。

.

代码块产生的实际错误来自方法org.springframework.web.context.request.async.StandardServletAsyncWebRequest.startAsync()，当getRequest().isAsyncSupported() 是false 时我们会收到此错误。尽管 ServletRegistrationBean#asyncSupported 的值为 true，但对于所有 API 请求，HttpServletRequest#isAsyncSupported() 方法的值始终设置为 false。

代码块Code Reference的摘录

Assert.state(getRequest().isAsyncSupported(),
                "Async support must be enabled on a servlet and for all filters involved " +
                "in async request processing. This is done in Java code using the Servlet API " +
                "or by adding \"<async-supported>true</async-supported>\" to servlet and " +
                "filter declarations in web.xml.");

在进一步分析时，我了解到 requestAttributes -> Globals.ASYNC_SUPPORTED_ATTR 决定是否必须以异步方式处理请求。

在正常情况下，请求没有 Globals.ASYNC_SUPPORTED_ATTR requestAttribute，因此 request.asyncSupported 将为 false，如果我们手动将 requestAttribute ASYNC_SUPPORTED_ATTR 值添加为 true，则使用过滤器之类的所有请求然后 request#asyncSupported根据下面的代码块Code Reference，值将设置为true

specialAttributes.put(Globals.ASYNC_SUPPORTED_ATTR,
                new SpecialAttributeAdapter() {
                    @Override
                    public Object get(Request request, String name) {
                        return request.asyncSupported;
                    }

                    @Override
                    public void set(Request request, String name, Object value) {
                        Boolean oldValue = request.asyncSupported;
                        request.asyncSupported = (Boolean)value;
                        request.notifyAttributeAssigned(name, value, oldValue);
                    }
                });

虽然没有明确的答案，但我已针对此问题实施了解决方法。总结所有需要的更改如下：

1. 添加过滤器将请求属性设置为request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, true)

@Component
public class AsyncSupportFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
        request.setAttribute(Globals.ASYNC_SUPPORTED_ATTR, true);
        chain.doFilter(request, response);
    }
}

1. 将过滤器添加到您的过滤器链中，在我的情况下，我已将过滤器注册到弹簧上下文中，如下所示。

@Component
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {
   @Autowired
   private AsyncSupportFilter asyncSupportFilter = null;
   @Override
   public void configure(HttpSecurity httpSecurity) {

       httpSecurity.addFilter(asyncSupportFilter);
       // we can add the filter before any filter like as httpSecurity.addFilterBefore(asyncSupportFilter , BasicAuthenticationFilter.class);
   }
}

Answer 3

也许值得一提的是，Spring Boot 默认为调度程序 servlet 和所有过滤器启用了异步支持

引用github:

我们自动将 async-supported 设置为 true 因为 DispatcherServlet 知道如何处理此类请求，并且 基本上取决于各个控制器方法来返回某些东西 就像一个 DeferredResult。此外，我们还为 任何过滤器（通过 getServletFilters 提供）以及设置 每个过滤器的 DispatcherType 都包含 ASYNC。

至少我的实践支持这种说法

Answer 4

你只需要定义dispatcherServlet@Bean：

@Bean
public ServletRegistrationBean dispatcherServlet() {
    ServletRegistrationBean registration = new ServletRegistrationBean(
            new DispatcherServlet(), "/");
    registration.setAsyncSupported(true);
    return registration;
}

它会覆盖 DispatcherServletAutoConfiguration 中的默认值。