如何在 Spring Boot 中缓存 CompletableFuture 的值

Question

我正在尝试在 Spring Boot 中使用CompletableFuture和Async 。

我有一个服务，它基本上返回一个String对象。 服务的方法上有@Cacheable ，这使得它可以从Redis 缓存中提供服务（如果可用）。

我有以下代码：

@Override
@Cacheable(value = "url-single", key = "#shortUrlKey", unless = "#result == null")
public Optional<String> retrieveOriginalUrl(String shortUrlKey) {
        LOG.info("Finding original URL with Short URL Key: {}", shortUrlKey);
        Optional<URLEntity> urlEntityOptional = urlRepository.findOneByShortUrlKey(shortUrlKey);
        if (urlEntityOptional.isPresent()) {
            LOG.info("Retrieved URL Entity: {}", urlEntityOptional.get());
            return Optional.of(urlEntityOptional.get().getOriginalUrl());
        }
        LOG.info("No URL Entity Retrieved");
        return Optional.empty();
}

当不涉及CompletableFuture时，上面的代码工作正常。

但是当方法修改如下时它崩溃了：

@Async
@Override
@Cacheable(value = "url-single", key = "#shortUrlKey", unless = "#result == null")
public CompletableFuture<Optional<String>> retrieveOriginalUrl(String shortUrlKey) {
        LOG.info("Finding original URL with Short URL Key: {}", shortUrlKey);
        Optional<URLEntity> urlEntityOptional = urlRepository.findOneByShortUrlKey(shortUrlKey);
        if (urlEntityOptional.isPresent()) {
            LOG.info("Retrieved URL Entity: {}", urlEntityOptional.get());
            return CompletableFuture.completedFuture(Optional.of(urlEntityOptional.get().getOriginalUrl()));
        }
        LOG.info("No URL Entity Retrieved");
        return CompletableFuture.completedFuture(Optional.empty());
    }

我使用Redisson进行缓存。 调用特定方法时会引发以下错误

java.lang.IllegalArgumentException: java.io.IOException: java.lang.RuntimeException: Class java.util.concurrent.CompletableFuture does not implement Serializable or externalizable
    at org.redisson.RedissonObject.encodeMapValue(RedissonObject.java:326) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.redisson.RedissonMap.fastPutOperationAsync(RedissonMap.java:931) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.redisson.RedissonMap.fastPutAsync(RedissonMap.java:922) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.redisson.RedissonMap.fastPut(RedissonMap.java:936) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.redisson.spring.cache.RedissonCache.put(RedissonCache.java:109) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.springframework.cache.interceptor.AbstractCacheInvoker.doPut(AbstractCacheInvoker.java:87) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.cache.interceptor.CacheAspectSupport$CachePutRequest.apply(CacheAspectSupport.java:820) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:429) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.cache.interceptor.CacheAspectSupport.execute(CacheAspectSupport.java:345) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.cache.interceptor.CacheInterceptor.invoke(CacheInterceptor.java:61) ~[spring-context-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) ~[spring-aop-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at com.sun.proxy.$Proxy92.retrieveOriginalUrlAsync(Unknown Source) ~[na:na]
    at in.turls.lib.controllers.v1.TestAsync.redirect(TestAsync.java:75) ~[classes!/:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:na]
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
    at java.base/java.lang.reflect.Method.invoke(Method.java:567) ~[na:na]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:190) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:138) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:106) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:888) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:793) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1040) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:943) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) ~[spring-webmvc-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) ~[tomcat-embed-websocket-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at in.turls.lib.filters.RequestResponseLoggingFilter.doFilter(RequestResponseLoggingFilter.java:28) ~[classes!/:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:119) ~[spring-web-5.2.2.RELEASE.jar!/:5.2.2.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:202) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:526) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:139) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:343) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:367) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:860) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1591) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) ~[na:na]
    at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) ~[na:na]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) ~[tomcat-embed-core-9.0.29.jar!/:9.0.29]
    at java.base/java.lang.Thread.run(Thread.java:830) ~[na:na]
Caused by: java.io.IOException: java.lang.RuntimeException: Class java.util.concurrent.CompletableFuture does not implement Serializable or externalizable
    at org.redisson.codec.FstCodec$2.encode(FstCodec.java:279) ~[redisson-3.12.1.jar!/:3.12.1]
    at org.redisson.RedissonObject.encodeMapValue(RedissonObject.java:324) ~[redisson-3.12.1.jar!/:3.12.1]
    ... 66 common frames omitted
Caused by: java.lang.RuntimeException: Class java.util.concurrent.CompletableFuture does not implement Serializable or externalizable
    at org.nustaq.serialization.FSTClazzInfo.<init>(FSTClazzInfo.java:144) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTClazzInfoRegistry.getCLInfo(FSTClazzInfoRegistry.java:129) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTObjectOutput.getFstClazzInfo(FSTObjectOutput.java:534) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTObjectOutput.writeObjectWithContext(FSTObjectOutput.java:416) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTObjectOutput.writeObjectInternal(FSTObjectOutput.java:327) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTObjectOutput.writeObject(FSTObjectOutput.java:294) ~[fst-2.57.jar!/:na]
    at org.nustaq.serialization.FSTObjectOutput.writeObject(FSTObjectOutput.java:204) ~[fst-2.57.jar!/:na]
    at org.redisson.codec.FstCodec$2.encode(FstCodec.java:271) ~[redisson-3.12.1.jar!/:3.12.1]
    ... 67 common frames omitted

当我使用Optional ，Spring 缓存能够只存储它的值，但是当使用CompletableFuture ，它无法这样做。 考虑到该方法必须只返回CompletableFuture的事实，我在这里有什么选择？

Answer 1

这个：

Class java.util.concurrent.CompletableFuture does not implement Serializable or externalizable

告诉您 Spring 缓存正在尝试序列化实际的 Future 对象，而不是其承诺的值。

根据 Spring 团队：Spring 缓存不支持（也不会）支持 CompletableFuture。

听起来这是更普遍的反应性努力的一部分。

您可以切换到使用项目反应器。 但是 Mono/Flux 也有自己的障碍。 另一种选择是直接使用缓存 API，例如Caffeine cache API或Redisson 。

看到这个问题： Spring @Cacheable and @Async annotation