【SpringMVC學習】啟用異步時報 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、報錯日志

嚴重: 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、解決辦法

<servlet>
    <servlet-name>springmvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/springmvc-servlet.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported> <%-- 配置上 --%>
</servlet>
<servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>
<filter>
    <filter-name>CharacterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
        <param-name>encoding</param-name>
        <param-value>UTF-8</param-value>
    </init-param>
    <init-param>
        <param-name>forceEncoding</param-name>
        <param-value>true</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
    <dispatcher>ASYNC</dispatcher> <%-- 配置上 --%>
</filter-mapping>
           

三、測試代碼

@RequestMapping(path="/home/callable")
@ResponseBody
public Callable<String> async() {
    System.out.println("通路時間:" + System.currentTimeMillis());
    Callable<String> callable = new Callable<String>() {
        @Override
        public String call() throws Exception {
            System.out.println("異步線程時間：" + System.currentTimeMillis());
            return "OK";
        }
    };
    System.out.println("主線程時間：" + System.currentTimeMillis());
    return callable;
}
           

四、參考連結

1. springMVC項目異步錯誤處理請求Async support must be enabled on a servlet and for all filters involved in async
2. Filter學習總結，順便提及點servlet3.0異步filter和異步監聽