Call `get(Request request)` on delegates.

docs/src/main/asciidoc/spring-cloud-commons.adoc

@@ -964,8 +964,8 @@ public class CustomLoadBalancerConfiguration {
 			ConfigurableApplicationContext context) {
 		return ServiceInstanceListSupplier.builder()
 					.withDiscoveryClient()
+                    .withCaching()
 					.withZonePreference()
-					.withCaching()
 					.build(context);
 	}
 }
@@ -1110,8 +1110,8 @@ public class CustomLoadBalancerConfiguration {
 			ConfigurableApplicationContext context) {
 		return ServiceInstanceListSupplier.builder()
 					.withDiscoveryClient()
+                    .withCaching()
 					.withHints()
-					.withCaching()
 					.build(context);
 	}
 }

spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/LoadBalancerProperties.java

@@ -73,6 +73,21 @@ public class LoadBalancerProperties {
 	 */
 	private boolean useRawStatusCodeInResponseData;
 
+	/**
+	 * If this flag is set to {@code true},
+	 * {@code ServiceInstanceListSupplier#get(Request request)} method will be implemented
+	 * to call {@code delegate.get(request)} in classes assignable from
+	 * {@code DelegatingServiceInstanceListSupplier} that don't already implement that
+	 * method, with the exclusion of {@code CachingServiceInstanceListSupplier} and
+	 * {@code HealthCheckServiceInstanceListSupplier}, which should be placed in the
+	 * instance supplier hierarchy directly after the supplier performing instance
+	 * retrieval over the network, before any request-based filtering is done.
+	 * @deprecated This flag will be removed in 4.1, where this behaviour will become the
+	 * default
+	 */
+	@Deprecated
+	private boolean callGetWithRequestOnDelegates;
+
 	public HealthCheck getHealthCheck() {
 		return healthCheck;
 	}
@@ -134,6 +149,40 @@ public class LoadBalancerProperties {
 		this.useRawStatusCodeInResponseData = useRawStatusCodeInResponseData;
 	}
 
+	/**
+	 * If this flag is set to {@code true},
+	 * {@code ServiceInstanceListSupplier#get(Request request)} method will be implemented
+	 * to call {@code delegate.get(request)} in classes assignable from
+	 * {@code DelegatingServiceInstanceListSupplier} that don't already implement that
+	 * method, with the exclusion of {@code CachingServiceInstanceListSupplier} and
+	 * {@code HealthCheckServiceInstanceListSupplier}, which should be placed in the
+	 * instance supplier hierarchy directly after the supplier performing instance
+	 * retrieval over the network, before any request-based filtering is done.
+	 * @deprecated This flag will be removed in 4.1, where this behaviour will become the
+	 * default
+	 */
+	@Deprecated
+	public boolean isCallGetWithRequestOnDelegates() {
+		return callGetWithRequestOnDelegates;
+	}
+
+	/**
+	 * If this flag is set to {@code true},
+	 * {@code ServiceInstanceListSupplier#get(Request request)} method will be implemented
+	 * to call {@code delegate.get(request)} in classes assignable from
+	 * {@code DelegatingServiceInstanceListSupplier} that don't already implement that
+	 * method, with the exclusion of {@code CachingServiceInstanceListSupplier} and
+	 * {@code HealthCheckServiceInstanceListSupplier}, which should be placed in the
+	 * instance supplier hierarchy directly after the supplier performing instance
+	 * retrieval over the network, before any request-based filtering is done.
+	 * @deprecated This flag will be removed in 4.1, where this behaviour will become the
+	 * default
+	 */
+	@Deprecated
+	public void setCallGetWithRequestOnDelegates(boolean callGetWithRequestOnDelegates) {
+		this.callGetWithRequestOnDelegates = callGetWithRequestOnDelegates;
+	}
+
 	public static class StickySession {
 
 		/**

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

@@ -93,7 +93,7 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(ZonePreferenceConfigurationCondition.class)
 		public ServiceInstanceListSupplier zonePreferenceDiscoveryClientServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withZonePreference().withCaching()
+			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withCaching().withZonePreference()
 					.build(context);
 		}
 
@@ -119,8 +119,8 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(RequestBasedStickySessionConfigurationCondition.class)
 		public ServiceInstanceListSupplier requestBasedStickySessionDiscoveryClientServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withRequestBasedStickySession()
-					.withCaching().build(context);
+			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withCaching()
+					.withRequestBasedStickySession().build(context);
 		}
 
 		@Bean
@@ -129,8 +129,8 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(SameInstancePreferenceConfigurationCondition.class)
 		public ServiceInstanceListSupplier sameInstancePreferenceServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withSameInstancePreference()
-					.withCaching().build(context);
+			return ServiceInstanceListSupplier.builder().withDiscoveryClient().withCaching()
+					.withSameInstancePreference().build(context);
 		}
 
 	}
@@ -155,8 +155,8 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(ZonePreferenceConfigurationCondition.class)
 		public ServiceInstanceListSupplier zonePreferenceDiscoveryClientServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withZonePreference()
-					.withCaching().build(context);
+			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withCaching()
+					.withZonePreference().build(context);
 		}
 
 		@Bean
@@ -175,8 +175,8 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(RequestBasedStickySessionConfigurationCondition.class)
 		public ServiceInstanceListSupplier requestBasedStickySessionDiscoveryClientServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withRequestBasedStickySession()
-					.withCaching().build(context);
+			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withCaching()
+					.withRequestBasedStickySession().build(context);
 		}
 
 		@Bean
@@ -185,8 +185,8 @@ public class LoadBalancerClientConfiguration {
 		@Conditional(SameInstancePreferenceConfigurationCondition.class)
 		public ServiceInstanceListSupplier sameInstancePreferenceServiceInstanceListSupplier(
 				ConfigurableApplicationContext context) {
-			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withSameInstancePreference()
-					.withCaching().build(context);
+			return ServiceInstanceListSupplier.builder().withBlockingDiscoveryClient().withCaching()
+					.withSameInstancePreference().build(context);
 		}
 
 	}

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

@@ -38,12 +38,12 @@ public abstract class DelegatingServiceInstanceListSupplier
 	}
 
 	public ServiceInstanceListSupplier getDelegate() {
-		return this.delegate;
+		return delegate;
 	}
 
 	@Override
 	public String getServiceId() {
-		return this.delegate.getServiceId();
+		return delegate.getServiceId();
 	}
 
 	@Override

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

@@ -24,6 +24,8 @@ import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Flux;
 
 import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.Request;
+import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
 
 /**
  * An implementation of {@link ServiceInstanceListSupplier} that selects the previously
@@ -39,10 +41,24 @@ public class SameInstancePreferenceServiceInstanceListSupplier extends Delegatin
 
 	private ServiceInstance previouslyReturnedInstance;
 
+	private boolean callGetWithRequestOnDelegates;
+
 	public SameInstancePreferenceServiceInstanceListSupplier(ServiceInstanceListSupplier delegate) {
 		super(delegate);
 	}
 
+	/**
+	 * @deprecated for removal in 4.1, where calling {@code get(Request request)} on
+	 * delegate will be the default behaviour.
+	 */
+	@Deprecated
+	public SameInstancePreferenceServiceInstanceListSupplier(ServiceInstanceListSupplier delegate,
+			ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerClientFactory) {
+		super(delegate);
+		callGetWithRequestOnDelegates = loadBalancerClientFactory.getProperties(getServiceId())
+				.isCallGetWithRequestOnDelegates();
+	}
+
 	@Override
 	public String getServiceId() {
 		return delegate.getServiceId();
@@ -53,6 +69,14 @@ public class SameInstancePreferenceServiceInstanceListSupplier extends Delegatin
 		return delegate.get().map(this::filteredBySameInstancePreference);
 	}
 
+	@Override
+	public Flux<List<ServiceInstance>> get(Request request) {
+		if (callGetWithRequestOnDelegates) {
+			return delegate.get(request).map(this::filteredBySameInstancePreference);
+		}
+		return get();
+	}
+
 	private List<ServiceInstance> filteredBySameInstancePreference(List<ServiceInstance> serviceInstances) {
 		if (previouslyReturnedInstance != null && serviceInstances.contains(previouslyReturnedInstance)) {
 			if (LOG.isDebugEnabled()) {

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

@@ -57,8 +57,6 @@ public final class ServiceInstanceListSupplierBuilder {
 
 	private Creator baseCreator;
 
-	private DelegateCreator cachingCreator;
-
 	private final List<DelegateCreator> creators = new ArrayList<>();
 
 	ServiceInstanceListSupplierBuilder() {
@@ -148,8 +146,10 @@ public final class ServiceInstanceListSupplierBuilder {
 	 * @return the {@link ServiceInstanceListSupplierBuilder} object
 	 */
 	public ServiceInstanceListSupplierBuilder withSameInstancePreference() {
-		DelegateCreator creator = (context,
-				delegate) -> new SameInstancePreferenceServiceInstanceListSupplier(delegate);
+		DelegateCreator creator = (context, delegate) -> {
+			LoadBalancerClientFactory loadBalancerClientFactory = context.getBean(LoadBalancerClientFactory.class);
+			return new SameInstancePreferenceServiceInstanceListSupplier(delegate, loadBalancerClientFactory);
+		};
 		this.creators.add(creator);
 		return this;
 	}
@@ -191,8 +191,9 @@ public final class ServiceInstanceListSupplierBuilder {
 	 */
 	public ServiceInstanceListSupplierBuilder withZonePreference() {
 		DelegateCreator creator = (context, delegate) -> {
+			LoadBalancerClientFactory loadBalancerClientFactory = context.getBean(LoadBalancerClientFactory.class);
 			LoadBalancerZoneConfig zoneConfig = context.getBean(LoadBalancerZoneConfig.class);
-			return new ZonePreferenceServiceInstanceListSupplier(delegate, zoneConfig);
+			return new ZonePreferenceServiceInstanceListSupplier(delegate, zoneConfig, loadBalancerClientFactory);
 		};
 		this.creators.add(creator);
 		return this;
@@ -206,8 +207,9 @@ public final class ServiceInstanceListSupplierBuilder {
 	 */
 	public ServiceInstanceListSupplierBuilder withZonePreference(String zoneName) {
 		DelegateCreator creator = (context, delegate) -> {
+			LoadBalancerClientFactory loadBalancerClientFactory = context.getBean(LoadBalancerClientFactory.class);
 			LoadBalancerZoneConfig zoneConfig = new LoadBalancerZoneConfig(zoneName);
-			return new ZonePreferenceServiceInstanceListSupplier(delegate, zoneConfig);
+			return new ZonePreferenceServiceInstanceListSupplier(delegate, zoneConfig, loadBalancerClientFactory);
 		};
 		this.creators.add(creator);
 		return this;
@@ -228,19 +230,15 @@ public final class ServiceInstanceListSupplierBuilder {
 	}
 
 	/**
-	 * If {@link LoadBalancerCacheManager} is available in the context, wraps created
-	 * {@link ServiceInstanceListSupplier} hierarchy with a
-	 * {@link CachingServiceInstanceListSupplier} instance to provide a caching mechanism
-	 * for service instances. Uses {@link ObjectProvider} to lazily resolve
+	 * If {@link LoadBalancerCacheManager} is available in the context, adds a
+	 * {@link CachingServiceInstanceListSupplier} instance to the
+	 * {@link ServiceInstanceListSupplier} hierarchy to provide a caching mechanism for
+	 * service instances. Uses {@link ObjectProvider} to lazily resolve
 	 * {@link LoadBalancerCacheManager}.
 	 * @return the {@link ServiceInstanceListSupplierBuilder} object
 	 */
 	public ServiceInstanceListSupplierBuilder withCaching() {
-		if (cachingCreator != null && LOG.isWarnEnabled()) {
-			LOG.warn(
-					"Overriding a previously set cachingCreator with a CachingServiceInstanceListSupplier-based cachingCreator.");
-		}
-		this.cachingCreator = (context, delegate) -> {
+		DelegateCreator creator = (context, delegate) -> {
 			ObjectProvider<LoadBalancerCacheManager> cacheManagerProvider = context
 					.getBeanProvider(LoadBalancerCacheManager.class);
 			if (cacheManagerProvider.getIfAvailable() != null) {
@@ -251,6 +249,7 @@ public final class ServiceInstanceListSupplierBuilder {
 			}
 			return delegate;
 		};
+		creators.add(creator);
 		return this;
 	}
 
@@ -297,9 +296,6 @@ public final class ServiceInstanceListSupplierBuilder {
 			supplier = creator.apply(context, supplier);
 		}
 
-		if (this.cachingCreator != null) {
-			supplier = this.cachingCreator.apply(context, supplier);
-		}
 		return supplier;
 	}
 

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

@@ -23,6 +23,8 @@ import java.util.Map;
 import reactor.core.publisher.Flux;
 
 import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.Request;
+import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
 import org.springframework.cloud.loadbalancer.config.LoadBalancerZoneConfig;
 
 /**
@@ -43,17 +45,41 @@ public class ZonePreferenceServiceInstanceListSupplier extends DelegatingService
 
 	private String zone;
 
+	private boolean callGetWithRequestOnDelegates;
+
 	public ZonePreferenceServiceInstanceListSupplier(ServiceInstanceListSupplier delegate,
 			LoadBalancerZoneConfig zoneConfig) {
 		super(delegate);
 		this.zoneConfig = zoneConfig;
 	}
 
+	/**
+	 * @deprecated for removal in 4.1, where calling {@code get(Request request)} on
+	 * delegate will be the default behaviour.
+	 */
+	@Deprecated
+	public ZonePreferenceServiceInstanceListSupplier(ServiceInstanceListSupplier delegate,
+			LoadBalancerZoneConfig zoneConfig,
+			ReactiveLoadBalancer.Factory<ServiceInstance> loadBalancerClientFactory) {
+		super(delegate);
+		this.zoneConfig = zoneConfig;
+		callGetWithRequestOnDelegates = loadBalancerClientFactory.getProperties(getServiceId())
+				.isCallGetWithRequestOnDelegates();
+	}
+
 	@Override
 	public Flux<List<ServiceInstance>> get() {
 		return getDelegate().get().map(this::filteredByZone);
 	}
 
+	@Override
+	public Flux<List<ServiceInstance>> get(Request request) {
+		if (callGetWithRequestOnDelegates) {
+			return getDelegate().get(request).map(this::filteredByZone);
+		}
+		return get();
+	}
+
 	private List<ServiceInstance> filteredByZone(List<ServiceInstance> serviceInstances) {
 		if (zone == null) {
 			zone = zoneConfig.getZone();

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

@@ -91,10 +91,10 @@ class LoadBalancerClientConfigurationTests {
 		reactiveDiscoveryClientRunner.withPropertyValues("spring.cloud.loadbalancer.configurations=zone-preference")
 				.run(context -> {
 					ServiceInstanceListSupplier supplier = context.getBean(ServiceInstanceListSupplier.class);
-					then(supplier).isInstanceOf(CachingServiceInstanceListSupplier.class);
+					then(supplier).isInstanceOf(ZonePreferenceServiceInstanceListSupplier.class);
 					ServiceInstanceListSupplier delegate = ((DelegatingServiceInstanceListSupplier) supplier)
 							.getDelegate();
-					then(delegate).isInstanceOf(ZonePreferenceServiceInstanceListSupplier.class);
+					then(delegate).isInstanceOf(CachingServiceInstanceListSupplier.class);
 					ServiceInstanceListSupplier secondDelegate = ((DelegatingServiceInstanceListSupplier) delegate)
 							.getDelegate();
 					then(secondDelegate).isInstanceOf(DiscoveryClientServiceInstanceListSupplier.class);
@@ -119,10 +119,10 @@ class LoadBalancerClientConfigurationTests {
 				.withPropertyValues("spring.cloud.loadbalancer.configurations=request-based-sticky-session")
 				.run(context -> {
 					ServiceInstanceListSupplier supplier = context.getBean(ServiceInstanceListSupplier.class);
-					then(supplier).isInstanceOf(CachingServiceInstanceListSupplier.class);
+					then(supplier).isInstanceOf(RequestBasedStickySessionServiceInstanceListSupplier.class);
 					ServiceInstanceListSupplier delegate = ((DelegatingServiceInstanceListSupplier) supplier)
 							.getDelegate();
-					then(delegate).isInstanceOf(RequestBasedStickySessionServiceInstanceListSupplier.class);
+					then(delegate).isInstanceOf(CachingServiceInstanceListSupplier.class);
 					ServiceInstanceListSupplier secondDelegate = ((DelegatingServiceInstanceListSupplier) delegate)
 							.getDelegate();
 					then(secondDelegate).isInstanceOf(DiscoveryClientServiceInstanceListSupplier.class);

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

@@ -37,11 +37,9 @@ public class ServiceInstanceListSupplierBuilderTests {
 	public void testBuilder() {
 		new ApplicationContextRunner().withUserConfiguration(CacheTestConfig.class).run(context -> {
 			ServiceInstanceListSupplier supplier = ServiceInstanceListSupplier.builder().withDiscoveryClient()
-					.withHealthChecks().withCaching().build(context);
-			assertThat(supplier).isInstanceOf(CachingServiceInstanceListSupplier.class);
+					.withHealthChecks().build(context);
+			assertThat(supplier).isInstanceOf(HealthCheckServiceInstanceListSupplier.class);
 			DelegatingServiceInstanceListSupplier delegating = (DelegatingServiceInstanceListSupplier) supplier;
-			assertThat(delegating.getDelegate()).isInstanceOf(HealthCheckServiceInstanceListSupplier.class);
-			delegating = (DelegatingServiceInstanceListSupplier) delegating.getDelegate();
 			assertThat(delegating.getDelegate()).isInstanceOf(DiscoveryClientServiceInstanceListSupplier.class);
 		});
 	}