【SpringMVC学习】启用异步时报 Async support must be enabled on a servlet and for all filters involved in async

Spring MVC has an extensive integration with Servlet 3.0 asynchronous request processing:

• DeferredResult and Callable return values in controller method provide basic support for a single asynchronous return value.
• Controllers can stream multiple values including SSE and raw data.
• Controllers can use reactive clients and return reactive types for response handling.

一、报错日志

严重: Servlet.service() for servlet [springmvc] in context with path [/cockroach-springmvc-xml] threw exception [Request processing failed; nested exception is java.lang.IllegalStateException: 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 “true” to servlet and filter declarations in web.xml.] with root cause
java.lang.IllegalStateException: 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 “true” to servlet and filter declarations in web.xml.
at org.springframework.util.Assert.state(Assert.java:73)
at org.springframework.web.context.request.async.StandardServletAsyncWebRequest.startAsync(StandardServletAsyncWebRequest.java:112)
at org.springframework.web.context.request.async.WebAsyncManager.startAsyncProcessing(WebAsyncManager.java:432)
at org.springframework.web.context.request.async.WebAsyncManager.startCallableProcessing(WebAsyncManager.java:311)
at org.springframework.web.context.request.async.WebAsyncManager.startCallableProcessing(WebAsyncManager.java:256)
at org.springframework.web.servlet.mvc.method.annotation.CallableMethodReturnValueHandler.handleReturnValue(CallableMethodReturnValueHandler.java:51)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:82)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:119)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:650)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol ConnectionHandler.process(AbstractProtocol.java:790)atorg.apache.tomcat.util.net.NioEndpoint C o n n e c t i o n H a n d l e r . p r o c e s s ( A b s t r a c t P r o t o c o l . j a v a : 790 ) a t o r g . a p a c h e . t o m c a t . u t i l . n e t . N i o E n d p o i n t SocketProcessor.doRun(NioEndpoint.java:1468)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor Worker.run(ThreadPoolExecutor.java:617)atorg.apache.tomcat.util.threads.TaskThread W o r k e r . r u n ( T h r e a d P o o l E x e c u t o r . j a v a : 617 ) a t o r g . a p a c h e . t o m c a t . u t i l . t h r e a d s . T a s k T h r e a d WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)

二、解决办法

<servlet>
    <servlet-name>springmvcservlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServletservlet-class>
    <init-param>
        <param-name>contextConfigLocationparam-name>
        <param-value>/WEB-INF/springmvc-servlet.xmlparam-value>
    init-param>
    <load-on-startup>1load-on-startup>
    <async-supported>trueasync-supported> <%-- 配置上 --%>
servlet>
<servlet-mapping>
    <servlet-name>springmvcservlet-name>
    <url-pattern>/url-pattern>
servlet-mapping>
<filter>
    <filter-name>CharacterEncodingFilterfilter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilterfilter-class>
    <init-param>
        <param-name>encodingparam-name>
        <param-value>UTF-8param-value>
    init-param>
    <init-param>
        <param-name>forceEncodingparam-name>
        <param-value>trueparam-value>
    init-param>
filter>
<filter-mapping>
    <filter-name>CharacterEncodingFilterfilter-name>
    <url-pattern>/*url-pattern>
    <dispatcher>ASYNCdispatcher> <%-- 配置上 --%>
filter-mapping>

三、测试代码

@RequestMapping(path="/home/callable")
@ResponseBody
public Callable async() {
    System.out.println("访问时间:" + System.currentTimeMillis());
    Callable callable = new Callable() {
        @Override
        public String call() throws Exception {
            System.out.println("异步线程时间：" + System.currentTimeMillis());
            return "OK";
        }
    };
    System.out.println("主线程时间：" + System.currentTimeMillis());
    return callable;
}

四、参考链接

1. springMVC项目异步错误处理请求Async support must be enabled on a servlet and for all filters involved in async
2. Filter学习总结，顺便提及点servlet3.0异步filter和异步监听