/* * Copyright 2013-2019 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * https://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.springframework.cloud.circuitbreaker.demo.reactivehystrixcircuitbreakerdemo; import reactor.core.publisher.Flux; import reactor.core.publisher.Mono; import rx.Observable; import rx.RxReactiveStreams; import rx.Subscription; import java.util.function.Function; import org.reactivestreams.Publisher; import com.netflix.hystrix.HystrixCommandGroupKey; import com.netflix.hystrix.HystrixCommandProperties; import com.netflix.hystrix.HystrixObservableCommand; /** * @author Ryan Baxter */ public class ReactiveHystrixCircuitBreaker /*implements CircuitBreaker*/ { private String id; private HystrixCommandProperties.Setter commandPropertiesSetter; public ReactiveHystrixCircuitBreaker(String id, HystrixCommandProperties.Setter commandPropertiesSetter) { this.id = id; this.commandPropertiesSetter = commandPropertiesSetter; } // @Override public <T> Mono<T> run(Mono<T> toRun) { return run(toRun, null); } // @Override public <T> Mono<T> run(Mono<T> toRun, Function<Throwable, Mono<T>> fallback) { HystrixObservableCommand<T> command = createCommand(toRun, fallback); return Mono.create(s -> { Subscription sub = command.toObservable().subscribe(s::success, s::error, s::success); s.onCancel(sub::unsubscribe); }); } public <T> Flux<T> run(Flux<T> toRun) { return run(toRun , null); } public <T> Flux<T> run(Flux<T> toRun, Function<Throwable, Flux<T>> fallback) { HystrixObservableCommand<T> command = createCommand(toRun, fallback); return Flux.create(s -> { Subscription sub = command.toObservable().subscribe(s::next, s::error, s::complete); s.onCancel(sub::unsubscribe); }); } private <T> HystrixObservableCommand<T> createCommand(Publisher<T> toRun, Function fallback) { HystrixObservableCommand.Setter setter = HystrixObservableCommand.Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey(id)) .andCommandPropertiesDefaults(commandPropertiesSetter); HystrixObservableCommand<T> command = new HystrixObservableCommand<T>(setter) { @Override protected Observable<T> construct() { return RxReactiveStreams.toObservable(toRun); } @Override protected Observable<T> resumeWithFallback() { if(fallback == null) { super.resumeWithFallback(); } return RxReactiveStreams.toObservable((Publisher)fallback.apply(this.getExecutionException())); } }; return command; } }