Update HystrixCommands to use a builder.

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/hystrix/HystrixCommands.java

@@ -17,10 +17,12 @@
 package org.springframework.cloud.netflix.hystrix;
 
 import org.reactivestreams.Publisher;
+import org.springframework.util.StringUtils;
 
 import com.netflix.hystrix.HystrixCommandGroupKey;
 import com.netflix.hystrix.HystrixCommandKey;
 import com.netflix.hystrix.HystrixObservableCommand;
+import com.netflix.hystrix.HystrixObservableCommand.Setter;
 
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
@@ -35,26 +37,99 @@ import rx.RxReactiveStreams;
  */
 public class HystrixCommands {
 
-	public static <T> Flux<T> wrap(String commandName, Flux<T> flux) {
-		return wrap(commandName, flux, null);
+	public static <T> PublisherBuilder<T> from(Publisher<T> publisher) {
+		return new PublisherBuilder<>(publisher);
 	}
 
-	public static <T> Flux<T> wrap(String commandName, Flux<T> flux, Flux<T> fallback) {
-		String groupName = commandName + "group";
-		PublisherHystrixCommand<T> command = createHystrixCommand(commandName, groupName,
-				flux, fallback);
-		return Flux.from(RxReactiveStreams.toPublisher(command.toObservable()));
-	}
+	public static class PublisherBuilder<T> {
+		private final Publisher<T> publisher;
+		private String commandName;
+		private String groupName;
+		private Publisher<T> fallback;
+		private Setter setter;
+		private boolean eager = false;
+
+		public PublisherBuilder(Publisher<T> publisher) {
+			this.publisher = publisher;
+		}
+
+		public PublisherBuilder<T> commandName(String commandName) {
+			this.commandName = commandName;
+			return this;
+		}
+
+		public PublisherBuilder<T> groupName(String groupName) {
+			this.groupName = groupName;
+			return this;
+		}
+
+		public PublisherBuilder<T> fallback(Publisher<T> fallback) {
+			this.fallback = fallback;
+			return this;
+		}
+
+		public PublisherBuilder<T> setter(Setter setter) {
+			this.setter = setter;
+			return this;
+		}
+
+		public PublisherBuilder<T> eager() {
+			this.eager = true;
+			return this;
+		}
+
+		public Publisher<T> build() {
+			if (!StringUtils.hasText(commandName) && setter == null) {
+				throw new IllegalStateException("commandName and setter can not both be empty");
+			}
+			Setter setterToUse;
+			if (this.setter != null) {
+				setterToUse = this.setter;
+			} else {
+				String groupNameToUse;
+				if (StringUtils.hasText(this.groupName)) {
+					groupNameToUse = this.groupName;
+				} else {
+					groupNameToUse = commandName + "group";
+				}
+
+				HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey(groupNameToUse);
+				HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey(this.commandName);
+				setterToUse = Setter.withGroupKey(groupKey).andCommandKey(commandKey);
+			}
+
+			PublisherHystrixCommand<T> command = new PublisherHystrixCommand<>(setterToUse, this.publisher, this.fallback);
+
+			Observable<T> observable;
+			if (this.eager) {
+				observable = command.observe();
+			} else {
+				observable = command.toObservable();
+			}
+			return RxReactiveStreams.toPublisher(observable);
+		}
+
+		public Flux<T> toFlux() {
+			return Flux.from(build());
+		}
+
+		public Mono<T> toMono() {
+			return Mono.from(build());
+		}
 
-	public static <T> Mono<T> wrap(String commandName, Mono<T> mono) {
-		return wrap(commandName, mono, null);
 	}
 
-	public static <T> Mono<T> wrap(String commandName, Mono<T> mono, Mono<T> fallback) {
+	public static <T> Mono<T> inject(String commandName, Mono<T> mono, Mono<T> fallback, boolean eager) {
 		String groupName = commandName + "group";
 		PublisherHystrixCommand<T> command = createHystrixCommand(commandName, groupName,
 				mono, fallback);
-		return Mono.from(RxReactiveStreams.toPublisher(command.toObservable()));
+		Observable<T> observable;
+		if (eager) {
+			observable = command.observe();
+		} else {
+			observable = command.toObservable();
+		}
+		return Mono.from(RxReactiveStreams.toPublisher(observable));
 	}
 
 	private static <T> PublisherHystrixCommand<T> createHystrixCommand(String commandName,
@@ -62,7 +137,7 @@ public class HystrixCommands {
 		HystrixCommandGroupKey groupKey = HystrixCommandGroupKey.Factory.asKey(groupName);
 		HystrixCommandKey commandKey = HystrixCommandKey.Factory.asKey(commandName);
 
-		HystrixObservableCommand.Setter setter = HystrixObservableCommand.Setter
+		Setter setter = Setter
 				.withGroupKey(groupKey).andCommandKey(commandKey);
 
 		return new PublisherHystrixCommand<>(setter, publisher, fallback);

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/hystrix/HystrixCommandsTests.java

@@ -36,47 +36,72 @@ public class HystrixCommandsTests {
 
 	@Test
 	public void monoWorks() {
-		String result = HystrixCommands.wrap("testworks", Mono.just("works")).block();
+		String result = HystrixCommands.from(Mono.just("works")).commandName("testworks").toMono().block();
+		assertThat(result).isEqualTo("works");
+	}
+
+	@Test
+	public void eagerMonoWorks() {
+		String result = HystrixCommands.from(Mono.just("works"))
+				.eager()
+				.commandName("testworks")
+				.toMono().block();
 		assertThat(result).isEqualTo("works");
 	}
 
 	@Test
 	public void monoTimesOut() {
 		exception.expect(HystrixRuntimeException.class);
-		HystrixCommands.wrap("failcmd", Mono.fromCallable(() -> {
+		HystrixCommands.from(Mono.fromCallable(() -> {
 			Thread.sleep(1500);
 			return "timeout";
-		})).block();
+		})).commandName("failcmd").toMono().block();
 	}
 
 	@Test
 	public void monoFallbackWorks() {
-		String result = HystrixCommands.wrap("failcmd", Mono.error(new Exception()), Mono.just("fallback")).block();
+		String result = HystrixCommands.from(Mono.<String>error(new Exception()))
+				.commandName("failcmd")
+				.fallback(Mono.just("fallback"))
+				.toMono().block();
 		assertThat(result).isEqualTo("fallback");
 	}
 
 	@Test
 	public void fluxWorks() {
-		List<String> list = HystrixCommands.wrap("multiflux", Flux.just("1", "2")).collectList().block();
+		List<String> list = HystrixCommands.from( Flux.just("1", "2"))
+				.commandName("multiflux")
+				.toFlux().collectList().block();
+		assertThat(list).hasSize(2).contains("1", "2");
+	}
+
+	@Test
+	public void eagerFluxWorks() {
+		List<String> list = HystrixCommands.from( Flux.just("1", "2"))
+				.commandName("multiflux")
+				.eager()
+				.toFlux().collectList().block();
 		assertThat(list).hasSize(2).contains("1", "2");
 	}
 
 	@Test
-	// @Ignore
 	public void fluxTimesOut() {
 		exception.expect(HystrixRuntimeException.class);
-		HystrixCommands.wrap("failcmd", Flux.from(s -> {
+		HystrixCommands.from( Flux.from(s -> {
 			try {
 				Thread.sleep(1500);
 			} catch (InterruptedException e) {
 				throw new RuntimeException(e);
 			}
-		})).blockFirst();
+		})).commandName("failcmd").toFlux().blockFirst();
 	}
 
 	@Test
 	public void fluxFallbackWorks() {
-		List<String> list = HystrixCommands.wrap("multiflux", Flux.error(new Exception()), Flux.just("a", "b")).collectList().block();
+		List<String> list = HystrixCommands.from(Flux.<String>error(new Exception()))
+				.commandName("multiflux")
+				.fallback(Flux.just("a", "b"))
+				.toFlux().collectList().block();
 		assertThat(list).hasSize(2).contains("a", "b");
 	}