Spring Boot enable like in web.xml

Question

I have a problem with Spring Boot configuration. I got exception on some mobile devices which should use sockets:

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)
    ...

As I see from the exception, I have to enable async processing by adding true into the web.xml file. But this is the problem because I don't have it - our project uses Spring Boot.

Is there any way to provide the same functionality in Spring Boot like does?

Answer 1

You just need to define dispatcherServlet @Bean:

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

It overrides that default one from DispatcherServletAutoConfiguration.

Answer 2

Maybe it worth to mention that Spring Boot has async-support enabled by default for dispatcher servlet and all filters

Quotation from github:

We automatically set async-supported to true because the DispatcherServlet knows how to work with such requests and it's basically up to individual controller methods to return something like a DeferredResult. Furthermore, we also set async-supported for any filter (provided via getServletFilters) along with setting the DispatcherType for each filter to include ASYNC.

At least my practice supports this statement