我在web.xml中声明了异步支持，并且 在setvlet-context.xml中设置任务配置。但是，我无法返回CompletableFuture类型。
如何使用异步注释和CompletableFuture？
我一直想知道怎么了？
web.xml显示如下：
<filter>
<filter-name>CharacterEncodingFilter</filter-name>
<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
<async-supported>true</async-supported>
<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>REQUEST</dispatcher>
<dispatcher>ASYNC</dispatcher>
</filter-mapping>
<servlet>
<servlet-name>dispatcher</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>/WEB-INF/config/servlet-context.xml</param-value>
</init-param>
<load-on-startup>1</load-on-startup>
<async-supported>true</async-supported>
<multipart-config />
</servlet>
<servlet-mapping>
<servlet-name>dispatcher</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
servlet-context.xml如下所示：
<task:annotation-driven />
<task:executor id="taskExecutor" pool-size="5-10" queue-capacity="25" />
<mvc:annotation-driven>
<mvc:message-converters>
<ref bean="mappingJackson2HttpMessageConverter" />
</mvc:message-converters>
<mvc:async-support default-timeout="5000" task-executor="taskExecutor" />
</mvc:annotation-driven>
<context:component-scan base-package="com.mango.study" use-default-filters="false">
<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller" />
<context:include-filter type="annotation" expression="org.springframework.web.bind.annotation.RestController" />
</context:component-scan>
异步注释如下所示：
package com.mango.study.common.util;
import org.springframework.scheduling.annotation.Async;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.Calendar;
import java.util.concurrent.CompletableFuture;
@Component
public class FileUtil {
public static final String SAVE_PATH = "/home/mingyu/photo/";
@Async
public CompletableFuture<String> saveFile(MultipartFile multiFile) throws IOException {
if (!multiFile.isEmpty()) {
String fileName = multiFile.getOriginalFilename();
String extName = fileName.substring(fileName.lastIndexOf("."));
String newFilePath = SAVE_PATH + makeFilename(extName);
File file = new File(newFilePath);
if (!file.getParentFile().exists()) {
file.getParentFile().mkdirs();
}
multiFile.transferTo(file);
}
System.out.println("The End to upload file");
return CompletableFuture.completedFuture("login/loginView");
}
public String makeFilename(String exetension) {
Calendar cal = Calendar.getInstance();
String year = String.valueOf(cal.get(Calendar.YEAR));
String month = String.valueOf(cal.get(Calendar.MONTH));
String day = String.valueOf(cal.get(Calendar.DAY_OF_MONTH));
String hour = String.valueOf(cal.get(Calendar.HOUR_OF_DAY));
String min = String.valueOf(cal.get(Calendar.MINUTE));
String sec = String.valueOf(cal.get(Calendar.SECOND));
String milSec = String.valueOf(cal.get(Calendar.MILLISECOND));
return year + month + day + hour + min + sec + milSec + exetension;
}
}
返回CompletableFuture如下所示：
@RequestMapping(value = "/login/loginView", method = RequestMethod.POST)
public CompletableFuture<String> loginViewPost(@Validated(LoginUser.FreeAccount.class) LoginUser inputLoginUser,
BindingResult result,
RedirectAttributes redirectAttributes) throws IOException {
redirectAttributes.addFlashAttribute(inputLoginUser);
if (result.hasErrors()) {
System.out.println("is it a password error? " + result.hasFieldErrors("password"));
}
MultipartFile file = inputLoginUser.getFile();
return fileUtil.saveFile(file);
}
错误消息如下所示：
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 "<async-supported>true</async-supported>" to servlet and filter declarations in web.xml.
at org.springframework.util.Assert.state(Assert.java:70)
at org.springframework.web.context.request.async.StandardServletAsyncWebRequest.startAsync(StandardServletAsyncWebRequest.java:109)
at org.springframework.web.context.request.async.WebAsyncManager.startAsyncProcessing(WebAsyncManager.java:456)
at org.springframework.web.context.request.async.WebAsyncManager.startDeferredResultProcessing(WebAsyncManager.java:434)
at org.springframework.web.servlet.mvc.method.annotation.DeferredResultMethodReturnValueHandler.handleReturnValue(DeferredResultMethodReturnValueHandler.java:107)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:81)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:113)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:660)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:741)
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:53)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
at org.springframework.web.multipart.support.MultipartFilter.doFilterInternal(MultipartFilter.java:122)
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.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93)
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:197)
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:199)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:490)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92)
at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:668)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:408)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:791)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1417)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:748)
20-May-2019 23:35:11.467 정보 [main] org.apache.catalina.core.ApplicationContext.log Destroying Spring FrameworkServlet 'dispatcher'
20-May-2019 23:35:11.477 경고 [main] org.apache.catalina.session.StandardSession.doWriteObject Cannot serialize session attribute [loginUser] for session [85939D636C7093B24F1944AB47CDBB8A]
java.io.NotSerializableException: org.apache.catalina.core.ApplicationPart
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at org.apache.catalina.session.StandardSession.doWriteObject(StandardSession.java:1667)
at org.apache.catalina.session.StandardSession.writeObjectData(StandardSession.java:1065)
at org.apache.catalina.session.StandardManager.doUnload(StandardManager.java:315)
at org.apache.catalina.session.StandardManager.unload(StandardManager.java:267)
at org.apache.catalina.session.StandardManager.stopInternal(StandardManager.java:382)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.core.StandardContext.stopInternal(StandardContext.java:5327)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1448)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1437)
at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
at java.util.concurrent.FutureTask.run(FutureTask.java)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
at org.apache.catalina.core.ContainerBase.stopInternal(ContainerBase.java:1004)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1448)
at org.apache.catalina.core.ContainerBase$StopChild.call(ContainerBase.java:1437)
at java.util.concurrent.FutureTask.run$$$capture(FutureTask.java:266)
at java.util.concurrent.FutureTask.run(FutureTask.java)
at org.apache.tomcat.util.threads.InlineExecutorService.execute(InlineExecutorService.java:75)
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:134)
at org.apache.catalina.core.ContainerBase.stopInternal(ContainerBase.java:1004)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.core.StandardService.stopInternal(StandardService.java:474)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.core.StandardServer.stopInternal(StandardServer.java:822)
at org.apache.catalina.util.LifecycleBase.stop(LifecycleBase.java:257)
at org.apache.catalina.startup.Catalina.stop(Catalina.java:768)
at org.apache.catalina.startup.Catalina.start(Catalina.java:730)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:350)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:492)
20-May-2019 23:35:11.478 정보 [main] org.apache.catalina.core.ApplicationContext.log Closing Spring root WebApplicationContext