Handle exception for restTemplate based function. Add default blockin…

…g health-check configuration.

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/annotation/LoadBalancerClientConfiguration.java

@@ -43,6 +43,8 @@
 import org.springframework.core.annotation.Order;
 import org.springframework.core.env.Environment;
 import org.springframework.retry.support.RetryTemplate;
+import org.springframework.web.client.RestTemplate;
+import org.springframework.web.reactive.function.client.WebClient;
 
 /**
  * @author Spencer Gibb
@@ -90,7 +92,7 @@ public ServiceInstanceListSupplier zonePreferenceDiscoveryClientServiceInstanceL
 		}
 
 		@Bean
-		@ConditionalOnBean(ReactiveDiscoveryClient.class)
+		@ConditionalOnBean({ ReactiveDiscoveryClient.class, WebClient.Builder.class })
 		@ConditionalOnMissingBean
 		@ConditionalOnProperty(value = "spring.cloud.loadbalancer.configurations", havingValue = "health-check")
 		public ServiceInstanceListSupplier healthCheckDiscoveryClientServiceInstanceListSupplier(
@@ -148,12 +150,12 @@ public ServiceInstanceListSupplier zonePreferenceDiscoveryClientServiceInstanceL
 		}
 
 		@Bean
-		@ConditionalOnBean(DiscoveryClient.class)
+		@ConditionalOnBean({ DiscoveryClient.class, RestTemplate.class })
 		@ConditionalOnMissingBean
 		@ConditionalOnProperty(value = "spring.cloud.loadbalancer.configurations", havingValue = "health-check")
 		public ServiceInstanceListSupplier healthCheckDiscoveryClientServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withHealthChecks()
+			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withBlockingHealthChecks()
 					.build(context);
 		}
 

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/core/HealthCheckServiceInstanceListSupplier.java

@@ -35,8 +35,8 @@
 
 /**
  * A {@link ServiceInstanceListSupplier} implementation that verifies whether the
- * instances are alive and only returns the healthy one, unless there are none. Uses
- * a user-provided function to ping the <code>health</code> endpoint of the instances.
+ * instances are alive and only returns the healthy one, unless there are none. Uses a
+ * user-provided function to ping the <code>health</code> endpoint of the instances.
  *
  * @author Olga Maciaszek-Sharma
  * @author Roman Matiushchenko
@@ -45,8 +45,7 @@
 public class HealthCheckServiceInstanceListSupplier extends DelegatingServiceInstanceListSupplier
 		implements InitializingBean, DisposableBean {
 
-	private static final Log LOG = LogFactory
-			.getLog(HealthCheckServiceInstanceListSupplier.class);
+	private static final Log LOG = LogFactory.getLog(HealthCheckServiceInstanceListSupplier.class);
 
 	private final LoadBalancerProperties.HealthCheck healthCheck;
 
@@ -62,20 +61,17 @@ public HealthCheckServiceInstanceListSupplier(ServiceInstanceListSupplier delega
 			LoadBalancerProperties.HealthCheck healthCheck,
 			BiFunction<ServiceInstance, String, Mono<Boolean>> aliveFunction) {
 		super(delegate);
-		defaultHealthCheckPath = healthCheck.getPath()
-				.getOrDefault("default", "/actuator/health");
+		defaultHealthCheckPath = healthCheck.getPath().getOrDefault("default", "/actuator/health");
 		this.aliveFunction = aliveFunction;
 		this.healthCheck = healthCheck;
 		Repeat<Object> aliveInstancesReplayRepeat = Repeat
 				.onlyIf(repeatContext -> this.healthCheck.getRefetchInstances())
 				.fixedBackoff(healthCheck.getRefetchInstancesInterval());
 		Flux<List<ServiceInstance>> aliveInstancesFlux = Flux.defer(delegate)
 				.switchMap(serviceInstances -> healthCheckFlux(serviceInstances)
-						.map(alive -> Collections
-								.unmodifiableList(new ArrayList<>(alive))))
+						.map(alive -> Collections.unmodifiableList(new ArrayList<>(alive))))
 				.repeatWhen(aliveInstancesReplayRepeat);
-		aliveInstancesReplay = aliveInstancesFlux
-				.delaySubscription(healthCheck.getInitialDelay()).replay(1)
+		aliveInstancesReplay = aliveInstancesFlux.delaySubscription(healthCheck.getInitialDelay()).replay(1)
 				.refCount(1);
 	}
 
@@ -130,8 +126,7 @@ public Flux<List<ServiceInstance>> get() {
 	}
 
 	protected Mono<Boolean> isAlive(ServiceInstance serviceInstance) {
-		String healthCheckPropertyValue = healthCheck.getPath()
-				.get(serviceInstance.getServiceId());
+		String healthCheckPropertyValue = healthCheck.getPath().get(serviceInstance.getServiceId());
 		String healthCheckPath = healthCheckPropertyValue != null ? healthCheckPropertyValue : defaultHealthCheckPath;
 		return aliveFunction.apply(serviceInstance, healthCheckPath);
 	}

spring-cloud-loadbalancer/src/main/java/org/springframework/cloud/loadbalancer/core/ServiceInstanceListSupplierBuilder.java

@@ -270,18 +270,17 @@ private ServiceInstanceListSupplier healthCheckServiceInstanceListSupplier(WebCl
 								.thenReturn(HttpStatus.OK.value() == clientResponse.rawStatusCode())));
 	}
 
-
 	private ServiceInstanceListSupplier blockingHealthCheckServiceInstanceListSupplier(RestTemplate restTemplate,
 			ServiceInstanceListSupplier delegate, LoadBalancerProperties properties) {
 		return new HealthCheckServiceInstanceListSupplier(delegate, properties.getHealthCheck(),
 				(serviceInstance, healthCheckPath) -> Mono.defer(() -> {
 					URI uri = UriComponentsBuilder.fromUri(serviceInstance.getUri()).path(healthCheckPath).build()
 							.toUri();
 					try {
-						return Mono.just(HttpStatus.OK
-								.equals(restTemplate.getForEntity(uri, Void.class)
-										.getStatusCode()));
-					} catch (Exception ignored){
+						return Mono
+								.just(HttpStatus.OK.equals(restTemplate.getForEntity(uri, Void.class).getStatusCode()));
+					}
+					catch (Exception ignored) {
 						return Mono.just(false);
 					}
 				}));

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/annotation/LoadBalancerClientConfigurationTests.java

@@ -37,6 +37,7 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.retry.support.RetryTemplate;
+import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.function.client.WebClient;
 
 import static org.assertj.core.api.BDDAssertions.then;
@@ -170,6 +171,17 @@ void shouldNotWrapWithRetryAwareSupplierWhenRetryTemplateOnClasspath() {
 
 	}
 
+	@Test
+	void shouldInstantiateBlockingHealthCheckServiceInstanceListSupplier() {
+		blockingDiscoveryClientRunner.withUserConfiguration(RestTemplateTestConfig.class)
+				.withPropertyValues("spring.cloud.loadbalancer.configurations=health-check").run(context -> {
+					ServiceInstanceListSupplier supplier = context.getBean(ServiceInstanceListSupplier.class);
+					then(supplier).isInstanceOf(HealthCheckServiceInstanceListSupplier.class);
+					then(((DelegatingServiceInstanceListSupplier) supplier).getDelegate())
+							.isInstanceOf(DiscoveryClientServiceInstanceListSupplier.class);
+				});
+	}
+
 	@Configuration
 	protected static class TestConfig {
 
@@ -181,4 +193,14 @@ WebClient.Builder webClientBuilder() {
 
 	}
 
+	@Configuration
+	protected static class RestTemplateTestConfig {
+
+		@Bean
+		RestTemplate restTemplate() {
+			return new RestTemplate();
+		}
+
+	}
+
 }

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/core/HealthCheckServiceInstanceListSupplierTests.java

@@ -125,7 +125,6 @@ void shouldCheckInstanceWithProvidedHealthCheckPathWithRestTemplate() {
 		assertThat(alive).isTrue();
 	}
 
-
 	@SuppressWarnings("ConstantConditions")
 	@Test
 	void shouldCheckInstanceWithDefaultHealthCheckPath() {

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/core/ServiceInstanceListSuppliersTestUtils.java

@@ -41,23 +41,18 @@ private ServiceInstanceListSuppliersTestUtils() {
 
 	static BiFunction<ServiceInstance, String, Mono<Boolean>> healthCheckFunction(WebClient webClient) {
 		return (serviceInstance, healthCheckPath) -> webClient.get()
-				.uri(UriComponentsBuilder.fromUri(serviceInstance.getUri())
-						.path(healthCheckPath).build().toUri())
+				.uri(UriComponentsBuilder.fromUri(serviceInstance.getUri()).path(healthCheckPath).build().toUri())
 				.exchange().flatMap(clientResponse -> clientResponse.releaseBody()
-						.thenReturn(HttpStatus.OK.value() == clientResponse
-								.rawStatusCode()));
+						.thenReturn(HttpStatus.OK.value() == clientResponse.rawStatusCode()));
 	}
 
 	static BiFunction<ServiceInstance, String, Mono<Boolean>> healthCheckFunction(RestTemplate restTemplate) {
 		return (serviceInstance, healthCheckPath) -> Mono.defer(() -> {
-			URI uri = UriComponentsBuilder.fromUri(serviceInstance.getUri())
-					.path(healthCheckPath).build()
-					.toUri();
+			URI uri = UriComponentsBuilder.fromUri(serviceInstance.getUri()).path(healthCheckPath).build().toUri();
 			try {
-				return Mono.just(HttpStatus.OK
-						.equals(restTemplate.getForEntity(uri, Void.class)
-								.getStatusCode()));
-			} catch (Exception ignored){
+				return Mono.just(HttpStatus.OK.equals(restTemplate.getForEntity(uri, Void.class).getStatusCode()));
+			}
+			catch (Exception ignored) {
 				return Mono.just(false);
 			}
 		});