Merge branch '5.0.x'

docs/modules/ROOT/pages/spring-cloud-commons/loadbalancer.adoc

@@ -204,7 +204,7 @@ WARNING: If using any of the Service Discovery-backed suppliers, adding this hea
 from the Service Registry.
 
 TIP: The `HealthCheckServiceInstanceListSupplier` relies on having updated instances provided by a delegate flux. In the rare cases when you want to use a delegate that does not refresh the instances, even though the list of instances may change (such as the `DiscoveryClientServiceInstanceListSupplier` provided by us), you can set `spring.cloud.loadbalancer.health-check.refetch-instances` to `true` to have the instance list refreshed by the `HealthCheckServiceInstanceListSupplier`. You can then also adjust the refretch intervals by modifying the value of `spring.cloud.loadbalancer.health-check.refetch-instances-interval` and opt to disable the additional healthcheck repetitions by setting `spring.cloud.loadbalancer.health-check.repeat-health-check` to `false` as every instances refetch
-  will also trigger a healthcheck.
+will also trigger a healthcheck.
 
 `HealthCheckServiceInstanceListSupplier` uses properties prefixed with
 `spring.cloud.loadbalancer.health-check`. You can set the `initialDelay` and `interval`
@@ -549,8 +549,41 @@ NOTE: For the properties where maps where already used, where you can specify a
 
 NOTE: Starting with `4.1.0`, we have introduced the `callGetWithRequestOnDelegates` flag in `LoadBalancerProperties`. If this flag is set to `true`, `ServiceInstanceListSupplier#get(Request request)` method will be implemented to call `delegate.get(request)` in classes assignable from `DelegatingServiceInstanceListSupplier` that don't already implement that method, with the exclusion of `CachingServiceInstanceListSupplier` and `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. It is set to `true` by default.
 
-[[-aot-and-native-image-support]]
+[[aot-and-native-image-support]]
 ==  AOT and Native Image Support
 
 Since `4.0.0`, Spring Cloud LoadBalancer supports Spring AOT transformations and native images. However, to use this feature, you need to explicitly define your `LoadBalancerClient` service IDs. You can do so by using the `value` or `name` attributes of the `@LoadBalancerClient` annotation or as values of the `spring.cloud.loadbalancer.eager-load.clients` property.
 
+== LoadBalancer Integration for Spring Interface Clients AutoConfiguration
+
+Since `5.0.0`, Spring Cloud LoadBalancer supports https://docs.spring.io/spring-framework/reference/7.0-SNAPSHOT/integration/rest-clients.html#rest-http-interface[Spring Interface Clients] AutoConfiguration through the `LoadBalancerRestClientHttpServiceGroupConfigurer` and `LoadBalancerWebClientHttpServiceGroupConfigurer`.
+
+For each Interface Client group, if the group `baseUrl` (defined under the
+`spring.http.client.service.group.[groupName].base-url` property) is `null`, a `serviceId`-based URL for load-balancing is set up as the `baseUrl`, with `serviceId` resolved from the Interface Client `groupName`.
+
+If the group `baseUrl` is `null` or its scheme is set to `lb`, a
+`DeferringLoadBalancerInterceptor` instance is picked from the application context for blocking scenarios, and a `DeferringLoadBalancerExchangeFilterFunction` instance for reactive scenarios, and is added to the group's `RestClient.Builder` or `WebClient.Builder` if available, allowing for the requests to be load-balanced.
+
+For example, in an app with the following Interface Clients configuration:
+
+[source,java,indent=0]
+----
+@SpringBootApplication
+@ImportHttpServices(group = "verificationClient", types = {VerificationService.class,
+		PersonService.class})
+public class HttpVerificationClientApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(HttpVerificationClientApplication.class, args);
+	}
+}
+----
+
+If the `spring.http.client.service.group.verificationClient.base-url` property is not set, it will be automatically set to `http://verificationClient`.
+The default scheme (`http`) is used initially; however, if a secure `ServiceInstance` is selected through load-balancing, it will be changed to `https`.
+
+If the `spring.http.client.service.group.verificationClient.base-url` property is set to a URL that has the `lb` scheme, (for example, `lb://verificationClient/path`), it will be used with `http` being initially set as the default scheme.
+If a secure `ServiceInstance` is selected through load-balancing, the scheme will be changed to `https`.
+In both of these cases, either a `DeferringLoadBalancerInterceptor` or `DeferringLoadBalancerExchangeFilterFunction` will be added to the group's client builder, enabling the requests to be load-balanced.
+
+If the `spring.http.client.service.group.verificationClient.base-url` property is set to a URL that does not have the scheme set to `lb`, (for example, `lb://verificationClient/path`), no load-balancer integration will be applied.

docs/modules/ROOT/partials/_configprops.adoc

@@ -1,7 +1,7 @@
 |===
 |Name | Default | Description
 
-|spring.cloud.compatibility-verifier.compatible-boot-versions | `+++3.5.x+++` | Default accepted versions for the Spring Boot dependency. You can set {@code x} for the patch version if you don't want to specify a concrete value. Example: {@code 3.5.x}
+|spring.cloud.compatibility-verifier.compatible-boot-versions | `+++4.0.x+++` | Default accepted versions for the Spring Boot dependency. You can set {@code x} for the patch version if you don't want to specify a concrete value. Example: {@code 3.5.x}
 |spring.cloud.compatibility-verifier.enabled | `+++false+++` | Enables creation of Spring Cloud compatibility verification.
 |spring.cloud.config.allow-override | `+++true+++` | Flag to indicate that {@link #isOverrideSystemProperties() systemPropertiesOverride} can be used. Set to false to prevent users from changing the default accidentally. Default true.
 |spring.cloud.config.initialize-on-context-refresh | `+++false+++` | Flag to initialize bootstrap configuration on context refresh event. Default false.

docs/pom.xml

@@ -8,7 +8,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 	</parent>
 	<packaging>jar</packaging>
 	<name>Spring Cloud Commons Docs</name>

pom.xml

@@ -5,7 +5,7 @@
 	<modelVersion>4.0.0</modelVersion>
 	<groupId>org.springframework.cloud</groupId>
 	<artifactId>spring-cloud-commons-parent</artifactId>
-	<version>4.3.1-SNAPSHOT</version>
+	<version>5.0.0-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<name>Spring Cloud Commons Parent</name>
 	<description>Spring Cloud Commons Parent</description>
@@ -13,7 +13,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-build</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>
 	<scm>

spring-cloud-commons-dependencies/pom.xml

@@ -6,11 +6,11 @@
 	<parent>
 		<artifactId>spring-cloud-dependencies-parent</artifactId>
 		<groupId>org.springframework.cloud</groupId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath/>
 	</parent>
 	<artifactId>spring-cloud-commons-dependencies</artifactId>
-	<version>4.3.1-SNAPSHOT</version>
+	<version>5.0.0-SNAPSHOT</version>
 	<packaging>pom</packaging>
 	<name>spring-cloud-commons-dependencies</name>
 	<description>Spring Cloud Commons Dependencies</description>

spring-cloud-commons/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-commons</artifactId>

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -30,6 +30,7 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
@@ -110,6 +111,15 @@ public class LoadBalancerAutoConfiguration {
 			return new LoadBalancerRestTemplateBuilderBeanPostProcessor<>(loadBalancerInterceptorProvider, context);
 		}
 
+		@Bean
+		@ConditionalOnBean({ HttpClientServiceProperties.class, ReactiveLoadBalancer.Factory.class })
+		@ConditionalOnMissingBean(LoadBalancerRestClientHttpServiceGroupConfigurer.class)
+		LoadBalancerRestClientHttpServiceGroupConfigurer loadBalancerRestClientHttpServiceGroupConfigurer(
+				ObjectProvider<DeferringLoadBalancerInterceptor> loadBalancerInterceptorProvider,
+				HttpClientServiceProperties properties) {
+			return new LoadBalancerRestClientHttpServiceGroupConfigurer(loadBalancerInterceptorProvider, properties);
+		}
+
 	}
 
 	@AutoConfiguration

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -145,8 +145,7 @@ public class LoadBalancerProperties {
 		this.hintHeaderName = hintHeaderName;
 	}
 
-	// TODO: fix spelling in a major release
-	public void setxForwarded(XForwarded xForwarded) {
+	public void setXForwarded(XForwarded xForwarded) {
 		this.xForwarded = xForwarded;
 	}
 

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

@@ -0,0 +1,99 @@
+/*
+ * Copyright 2012-2025 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.client.loadbalancer;
+
+import java.net.URI;
+
+import org.jspecify.annotations.NonNull;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties;
+import org.springframework.util.function.SingletonSupplier;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.client.support.RestClientHttpServiceGroupConfigurer;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import static org.springframework.cloud.client.loadbalancer.LoadBalancerUriTools.DEFAULT_SCHEME;
+import static org.springframework.cloud.client.loadbalancer.LoadBalancerUriTools.constructInterfaceClientsBaseUrl;
+
+/**
+ * Load-balancer-specific {@link RestClientHttpServiceGroupConfigurer} implementation. If
+ * the group {@code baseUrl} is {@code null}, sets up a {@code baseUrl} with LoadBalancer
+ * {@code serviceId} -resolved from Interface Client {@code groupName} set as
+ * {@code host}. If the group {@code baseUrl} is {@code null} or has {@code lb} set as its
+ * scheme, a {@link DeferringLoadBalancerInterceptor} instance picked from application
+ * context is added to the group's {@link RestClient.Builder} if available, allowing for
+ * the requests to be load-balanced.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 5.0.0
+ * @see RestClientHttpServiceGroupConfigurer
+ * @see HttpClientServiceProperties
+ */
+public class LoadBalancerRestClientHttpServiceGroupConfigurer implements RestClientHttpServiceGroupConfigurer {
+
+	// Make sure Boot's configurers run before
+	private static final int ORDER = 10;
+
+	private final SingletonSupplier<DeferringLoadBalancerInterceptor> loadBalancerInterceptorSupplier;
+
+	private final HttpClientServiceProperties clientServiceProperties;
+
+	public LoadBalancerRestClientHttpServiceGroupConfigurer(
+			ObjectProvider<DeferringLoadBalancerInterceptor> loadBalancerInterceptorProvider,
+			HttpClientServiceProperties clientServiceProperties) {
+		this.loadBalancerInterceptorSupplier = SingletonSupplier
+			.ofNullable(loadBalancerInterceptorProvider::getIfAvailable);
+		this.clientServiceProperties = clientServiceProperties;
+	}
+
+	@Override
+	public void configureGroups(@NonNull Groups<RestClient.Builder> groups) {
+		DeferringLoadBalancerInterceptor loadBalancerInterceptor = loadBalancerInterceptorSupplier.get();
+		if (loadBalancerInterceptor == null) {
+			throw new IllegalStateException(
+					DeferringLoadBalancerInterceptor.class.getSimpleName() + " bean not available.");
+		}
+
+		groups.forEachGroup((group, clientBuilder, factoryBuilder) -> {
+			String groupName = group.name();
+			HttpClientServiceProperties.Group groupProperties = clientServiceProperties.getGroup().get(groupName);
+			String baseUrlString = groupProperties == null ? null : groupProperties.getBaseUrl();
+			URI existingBaseUrl = baseUrlString == null ? null : URI.create(baseUrlString);
+			if (existingBaseUrl == null) {
+				URI baseUrl = constructBaseUrl(groupName);
+				clientBuilder.baseUrl(baseUrl);
+				clientBuilder.requestInterceptor(loadBalancerInterceptor);
+			}
+			else if ("lb".equalsIgnoreCase(existingBaseUrl.getScheme())) {
+				URI baseUrl = UriComponentsBuilder.fromUri(existingBaseUrl).scheme(DEFAULT_SCHEME).build().toUri();
+				clientBuilder.baseUrl(baseUrl);
+				clientBuilder.requestInterceptor(loadBalancerInterceptor);
+			}
+		});
+	}
+
+	@Override
+	public int getOrder() {
+		return ORDER;
+	}
+
+	private URI constructBaseUrl(String groupName) {
+		return constructInterfaceClientsBaseUrl(groupName);
+	}
+
+}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -37,12 +37,15 @@ public final class LoadBalancerUriTools {
 
 	private static final String PERCENTAGE_SIGN = "%";
 
-	private static final String DEFAULT_SCHEME = "http";
-
 	private static final String DEFAULT_SECURE_SCHEME = "https";
 
 	private static final Map<String, String> INSECURE_SCHEME_MAPPINGS;
 
+	/**
+	 * Default scheme.
+	 */
+	public static final String DEFAULT_SCHEME = "http";
+
 	static {
 		INSECURE_SCHEME_MAPPINGS = new HashMap<>();
 		INSECURE_SCHEME_MAPPINGS.put(DEFAULT_SCHEME, DEFAULT_SECURE_SCHEME);
@@ -115,4 +118,8 @@ public final class LoadBalancerUriTools {
 		return originalOrDefault;
 	}
 
+	public static URI constructInterfaceClientsBaseUrl(String groupName) {
+		return UriComponentsBuilder.newInstance().scheme(DEFAULT_SCHEME).host(groupName).encode().build().toUri();
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -29,6 +29,7 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpRequest;
 import org.springframework.http.server.reactive.ServerHttpRequest;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.client.ClientRequest;
 
@@ -80,7 +81,7 @@ public class RequestData {
 	}
 
 	private static MultiValueMap<String, String> buildCookies(MultiValueMap<String, HttpCookie> cookies) {
-		HttpHeaders newCookies = new HttpHeaders();
+		MultiValueMap<String, String> newCookies = new LinkedMultiValueMap<>();
 		if (cookies != null) {
 			cookies.forEach((key, value) -> value
 				.forEach(cookie -> newCookies.put(cookie.getName(), Collections.singletonList(cookie.getValue()))));
@@ -89,7 +90,7 @@ public class RequestData {
 	}
 
 	private static MultiValueMap<String, String> buildCookiesFromHeaders(HttpHeaders headers) {
-		HttpHeaders newCookies = new HttpHeaders();
+		MultiValueMap<String, String> newCookies = new LinkedMultiValueMap<>();
 		if (headers == null) {
 			return newCookies;
 		}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -21,6 +21,8 @@ import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.boot.autoconfigure.condition.AnyNestedCondition;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.http.client.reactive.service.ReactiveHttpClientServiceProperties;
 import org.springframework.cloud.client.loadbalancer.LoadBalanced;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
 import org.springframework.context.ApplicationContext;
@@ -66,6 +68,15 @@ public class LoadBalancerBeanPostProcessorAutoConfiguration {
 			return new DeferringLoadBalancerExchangeFilterFunction<>(exchangeFilterFunctionProvider);
 		}
 
+		@Bean
+		@ConditionalOnBean({ ReactiveHttpClientServiceProperties.class, ReactiveLoadBalancer.Factory.class })
+		@ConditionalOnMissingBean(LoadBalancerWebClientHttpServiceGroupConfigurer.class)
+		LoadBalancerWebClientHttpServiceGroupConfigurer loadBalancerWebClientHttpServiceGroupConfigurer(
+				ObjectProvider<DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction>> deferringExchangeFilterFunction,
+				ReactiveHttpClientServiceProperties properties) {
+			return new LoadBalancerWebClientHttpServiceGroupConfigurer(deferringExchangeFilterFunction, properties);
+		}
+
 	}
 
 	static final class OnAnyLoadBalancerImplementationPresentCondition extends AnyNestedCondition {

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

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2012-2025 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.client.loadbalancer.reactive;
+
+import java.net.URI;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.http.client.reactive.service.ReactiveHttpClientServiceProperties;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties;
+import org.springframework.util.function.SingletonSupplier;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.support.WebClientHttpServiceGroupConfigurer;
+import org.springframework.web.util.UriComponentsBuilder;
+
+import static org.springframework.cloud.client.loadbalancer.LoadBalancerUriTools.DEFAULT_SCHEME;
+import static org.springframework.cloud.client.loadbalancer.LoadBalancerUriTools.constructInterfaceClientsBaseUrl;
+
+/**
+ * Load-balancer-specific {@link WebClientHttpServiceGroupConfigurer} implementation. If
+ * the group {@code baseUrl} is {@code null}, sets up a {@code baseUrl} with LoadBalancer
+ * {@code serviceId} -resolved from Interface Client {@code groupName} set as
+ * {@code host}. If the group {@code baseUrl} is {@code null} or has {@code lb} set as its
+ * scheme, a {@link DeferringLoadBalancerExchangeFilterFunction} instance picked from
+ * application context is added to the group's {@link WebClient.Builder} if available,
+ * allowing for the requests to be load-balanced.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 5.0.0
+ * @see WebClient.Builder
+ * @see HttpClientServiceProperties
+ */
+public class LoadBalancerWebClientHttpServiceGroupConfigurer implements WebClientHttpServiceGroupConfigurer {
+
+	// Make sure Boot's configurers run before
+	private static final int ORDER = 10;
+
+	private final SingletonSupplier<DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction>> loadBalancerFilterFunctionSupplier;
+
+	private final ReactiveHttpClientServiceProperties clientServiceProperties;
+
+	public LoadBalancerWebClientHttpServiceGroupConfigurer(
+			ObjectProvider<DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction>> exchangeFilterFunctionProvider,
+			ReactiveHttpClientServiceProperties clientServiceProperties) {
+		this.loadBalancerFilterFunctionSupplier = SingletonSupplier
+			.ofNullable(exchangeFilterFunctionProvider::getIfAvailable);
+		this.clientServiceProperties = clientServiceProperties;
+	}
+
+	@Override
+	public void configureGroups(Groups<WebClient.Builder> groups) {
+		DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction> loadBalancerFilterFunction = loadBalancerFilterFunctionSupplier
+			.get();
+		if (loadBalancerFilterFunction == null) {
+			throw new IllegalStateException(
+					DeferringLoadBalancerExchangeFilterFunction.class.getSimpleName() + " bean not available.");
+		}
+		groups.forEachGroup((group, clientBuilder, factoryBuilder) -> {
+			String groupName = group.name();
+			ReactiveHttpClientServiceProperties.Group groupProperties = clientServiceProperties.getGroup()
+				.get(groupName);
+			String baseUrlString = groupProperties == null ? null : groupProperties.getBaseUrl();
+			URI existingBaseUrl = baseUrlString == null ? null : URI.create(baseUrlString);
+			if (existingBaseUrl == null) {
+				URI baseUrl = constructBaseUrl(groupName);
+				clientBuilder.baseUrl(String.valueOf(baseUrl));
+				clientBuilder.filter(loadBalancerFilterFunction);
+			}
+			else if ("lb".equalsIgnoreCase(existingBaseUrl.getScheme())) {
+				String baseUrl = UriComponentsBuilder.fromUri(existingBaseUrl)
+					.scheme(DEFAULT_SCHEME)
+					.build()
+					.toUriString();
+				clientBuilder.baseUrl(baseUrl);
+				clientBuilder.filter(loadBalancerFilterFunction);
+			}
+		});
+	}
+
+	@Override
+	public int getOrder() {
+		return ORDER;
+	}
+
+	private URI constructBaseUrl(String groupName) {
+		return constructInterfaceClientsBaseUrl(groupName);
+	}
+
+}

spring-cloud-commons/src/main/java/org/springframework/cloud/configuration/CompatibilityVerifierProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -22,6 +22,7 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 
 /**
  * @author Marcin Grzejszczak
+ * @author Olga Maciaszek-Sharma
  */
 @ConfigurationProperties("spring.cloud.compatibility-verifier")
 public class CompatibilityVerifierProperties {
@@ -36,7 +37,7 @@ public class CompatibilityVerifierProperties {
 	 * the patch version if you don't want to specify a concrete value. Example:
 	 * {@code 3.5.x}
 	 */
-	private List<String> compatibleBootVersions = List.of("3.5.x");
+	private List<String> compatibleBootVersions = List.of("4.0.x");
 
 	public boolean isEnabled() {
 		return this.enabled;

spring-cloud-commons/src/main/java/org/springframework/cloud/configuration/SpringBootVersionVerifier.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -27,7 +27,7 @@ import org.springframework.boot.SpringBootVersion;
 import org.springframework.util.StringUtils;
 
 /**
- * Verifies if Spring Boot has proper version.
+ * Verifies if Spring Boot has the proper version.
  */
 class SpringBootVersionVerifier implements CompatibilityVerifier {
 
@@ -35,7 +35,7 @@ class SpringBootVersionVerifier implements CompatibilityVerifier {
 
 	final Map<String, CompatibilityPredicate> ACCEPTED_VERSIONS = new HashMap<>() {
 		{
-			this.put("3.5", is3_5());
+			this.put("4.0", is4_0());
 		}
 	};
 
@@ -70,12 +70,12 @@ class SpringBootVersionVerifier implements CompatibilityVerifier {
 		return SpringBootVersion.getVersion();
 	}
 
-	CompatibilityPredicate is3_5() {
+	CompatibilityPredicate is4_0() {
 		return new CompatibilityPredicate() {
 
 			@Override
 			public String toString() {
-				return "Predicate for Boot 3.5";
+				return "Predicate for Boot 4.0";
 			}
 
 			@Override

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/AbstractLoadBalancerAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -25,9 +25,11 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.cloud.client.DefaultServiceInstance;
 import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerWebClientHttpServiceGroupConfigurer;
 import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -154,6 +156,14 @@ public abstract class AbstractLoadBalancerAutoConfigurationTests {
 			});
 	}
 
+	@Test
+	void loadBalancerRestClientHttpServiceGroupConfigurerPresent() {
+		applicationContextRunner.withUserConfiguration(OneRestClientBuilder.class).run(context -> {
+			assertThat(context.getBeansOfType(LoadBalancerRestClientHttpServiceGroupConfigurer.class)).hasSize(1);
+			assertThat(context.getBeansOfType(LoadBalancerWebClientHttpServiceGroupConfigurer.class)).hasSize(0);
+		});
+	}
+
 	protected abstract void assertLoadBalanced(RestClient.Builder restClientBuilder);
 
 	protected abstract void assertLoadBalanced(RestTemplate restTemplate);
@@ -180,6 +190,11 @@ public abstract class AbstractLoadBalancerAutoConfigurationTests {
 			return RestClient.builder();
 		}
 
+		@Bean
+		HttpClientServiceProperties httpClientServiceProperties() {
+			return new HttpClientServiceProperties();
+		}
+
 	}
 
 	@Configuration(proxyBeanMethods = false)

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/LoadBalancerRestClientHttpServiceGroupConfigurerTests.java

@@ -0,0 +1,141 @@
+/*
+ * Copyright 2012-2025 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.client.loadbalancer;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties;
+import org.springframework.boot.autoconfigure.http.client.service.HttpClientServiceProperties.Group;
+import org.springframework.web.client.RestClient;
+import org.springframework.web.service.invoker.HttpServiceProxyFactory;
+import org.springframework.web.service.registry.HttpServiceGroup;
+import org.springframework.web.service.registry.HttpServiceGroupConfigurer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link LoadBalancerRestClientHttpServiceGroupConfigurer}
+ *
+ * @author Olga Maciaszek-Sharma
+ */
+@SuppressWarnings({ "removal" })
+class LoadBalancerRestClientHttpServiceGroupConfigurerTests {
+
+	private static final String GROUP_NAME = "testService";
+
+	private HttpClientServiceProperties clientServiceProperties;
+
+	private ObjectProvider<DeferringLoadBalancerInterceptor> interceptorProvider;
+
+	@BeforeEach
+	void setup() {
+		DeferringLoadBalancerInterceptor interceptor = mock(DeferringLoadBalancerInterceptor.class);
+		interceptorProvider = new SimpleObjectProvider<>(interceptor);
+		clientServiceProperties = new HttpClientServiceProperties();
+	}
+
+	@Test
+	void shouldAddInterceptorWhenBaseUrlIsNotSet() {
+		LoadBalancerRestClientHttpServiceGroupConfigurer configurer = new LoadBalancerRestClientHttpServiceGroupConfigurer(
+				interceptorProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.requestInterceptors(interceptors -> {
+			assertThat(interceptors).hasSize(1);
+			assertThat(interceptors.get(0).getClass()).isEqualTo(DeferringLoadBalancerInterceptor.class);
+		});
+	}
+
+	@Test
+	void shouldAddInterceptorWhenBaseUrlHasLbScheme() {
+		Group group = new Group();
+		group.setBaseUrl("lb://" + GROUP_NAME + "/path");
+		clientServiceProperties.getGroup().put(GROUP_NAME, group);
+		LoadBalancerRestClientHttpServiceGroupConfigurer configurer = new LoadBalancerRestClientHttpServiceGroupConfigurer(
+				interceptorProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.requestInterceptors(interceptors -> {
+			assertThat(interceptors).hasSize(1);
+			assertThat(interceptors.get(0).getClass()).isEqualTo(DeferringLoadBalancerInterceptor.class);
+		});
+	}
+
+	@Test
+	void shouldNotAddInterceptorWhenBaseDoesNotHaveLbScheme() {
+		Group group = new Group();
+		group.setBaseUrl("http://" + GROUP_NAME + "/path");
+		clientServiceProperties.getGroup().put(GROUP_NAME, group);
+		LoadBalancerRestClientHttpServiceGroupConfigurer configurer = new LoadBalancerRestClientHttpServiceGroupConfigurer(
+				interceptorProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.requestInterceptors(interceptors -> assertThat(interceptors).hasSize(0));
+	}
+
+	private static class TestGroups implements HttpServiceGroupConfigurer.Groups<RestClient.Builder> {
+
+		RestClient.Builder builder = RestClient.builder();
+
+		@Override
+		public HttpServiceGroupConfigurer.Groups<RestClient.Builder> filterByName(String... groupNames) {
+			throw new UnsupportedOperationException("Please, implement me.");
+		}
+
+		@Override
+		public HttpServiceGroupConfigurer.Groups<RestClient.Builder> filter(Predicate<HttpServiceGroup> predicate) {
+			throw new UnsupportedOperationException("Please, implement me.");
+		}
+
+		@Override
+		public void forEachClient(HttpServiceGroupConfigurer.ClientCallback<RestClient.Builder> configurer) {
+
+		}
+
+		@Override
+		public void forEachProxyFactory(HttpServiceGroupConfigurer.ProxyFactoryCallback configurer) {
+
+		}
+
+		@Override
+		public void forEachGroup(HttpServiceGroupConfigurer.GroupCallback<RestClient.Builder> groupConfigurer) {
+			groupConfigurer.withGroup(
+					new TestGroup(GROUP_NAME, HttpServiceGroup.ClientType.REST_CLIENT, new HashSet<>()), builder,
+					HttpServiceProxyFactory.builder());
+		}
+
+	}
+
+	private record TestGroup(String name, ClientType clientType,
+			Set<Class<?>> httpServiceTypes) implements HttpServiceGroup {
+
+	}
+
+}

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/LoadBalancerUriToolsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/reactive/LoadBalancerWebClientHttpServiceGroupConfigurerTests.java

@@ -0,0 +1,143 @@
+/*
+ * Copyright 2012-2025 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.client.loadbalancer.reactive;
+
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Predicate;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.ObjectProvider;
+import org.springframework.boot.autoconfigure.http.client.reactive.service.ReactiveHttpClientServiceProperties;
+import org.springframework.cloud.client.loadbalancer.SimpleObjectProvider;
+import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.service.invoker.HttpServiceProxyFactory;
+import org.springframework.web.service.registry.HttpServiceGroup;
+import org.springframework.web.service.registry.HttpServiceGroupConfigurer;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.Mockito.mock;
+
+/**
+ * Tests for {@link LoadBalancerWebClientHttpServiceGroupConfigurer}
+ *
+ * @author Olga Maciaszek-Sharma
+ */
+@SuppressWarnings({ "unchecked", "removal" })
+class LoadBalancerWebClientHttpServiceGroupConfigurerTests {
+
+	private static final String GROUP_NAME = "testService";
+
+	private ReactiveHttpClientServiceProperties clientServiceProperties;
+
+	private ObjectProvider<DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction>> exchangeFilterFunctionProvider;
+
+	@BeforeEach
+	void setup() {
+		DeferringLoadBalancerExchangeFilterFunction<LoadBalancedExchangeFilterFunction> exchangeFilterFunction = mock(
+				DeferringLoadBalancerExchangeFilterFunction.class);
+		exchangeFilterFunctionProvider = new SimpleObjectProvider<>(exchangeFilterFunction);
+		clientServiceProperties = new ReactiveHttpClientServiceProperties();
+	}
+
+	@Test
+	void shouldAddInterceptorWhenBaseUrlIsNotSet() {
+		LoadBalancerWebClientHttpServiceGroupConfigurer configurer = new LoadBalancerWebClientHttpServiceGroupConfigurer(
+				exchangeFilterFunctionProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.filters(filterFunctions -> {
+			assertThat(filterFunctions).hasSize(1);
+			assertThat(filterFunctions.get(0).getClass()).isEqualTo(DeferringLoadBalancerExchangeFilterFunction.class);
+		});
+	}
+
+	@Test
+	void shouldAddInterceptorWhenBaseUrlHasLbScheme() {
+		ReactiveHttpClientServiceProperties.Group group = new ReactiveHttpClientServiceProperties.Group();
+		group.setBaseUrl("lb://" + GROUP_NAME + "/path");
+		clientServiceProperties.getGroup().put(GROUP_NAME, group);
+		LoadBalancerWebClientHttpServiceGroupConfigurer configurer = new LoadBalancerWebClientHttpServiceGroupConfigurer(
+				exchangeFilterFunctionProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.filters(filterFunctions -> {
+			assertThat(filterFunctions).hasSize(1);
+			assertThat(filterFunctions.get(0).getClass()).isEqualTo(DeferringLoadBalancerExchangeFilterFunction.class);
+		});
+	}
+
+	@Test
+	void shouldNotAddInterceptorWhenBaseDoesNotHaveLbScheme() {
+		ReactiveHttpClientServiceProperties.Group group = new ReactiveHttpClientServiceProperties.Group();
+		group.setBaseUrl("https://" + GROUP_NAME + "/path");
+		clientServiceProperties.getGroup().put(GROUP_NAME, group);
+		LoadBalancerWebClientHttpServiceGroupConfigurer configurer = new LoadBalancerWebClientHttpServiceGroupConfigurer(
+				exchangeFilterFunctionProvider, clientServiceProperties);
+		TestGroups groups = new TestGroups();
+
+		configurer.configureGroups(groups);
+
+		groups.builder.filters(filterFunctions -> assertThat(filterFunctions).hasSize(0));
+	}
+
+	private static class TestGroups implements HttpServiceGroupConfigurer.Groups<WebClient.Builder> {
+
+		WebClient.Builder builder = WebClient.builder();
+
+		//
+		@Override
+		public HttpServiceGroupConfigurer.Groups<WebClient.Builder> filterByName(String... groupNames) {
+			throw new UnsupportedOperationException("Please, implement me.");
+		}
+
+		@Override
+		public HttpServiceGroupConfigurer.Groups<WebClient.Builder> filter(Predicate<HttpServiceGroup> predicate) {
+			throw new UnsupportedOperationException("Please, implement me.");
+		}
+
+		@Override
+		public void forEachClient(HttpServiceGroupConfigurer.ClientCallback<WebClient.Builder> configurer) {
+
+		}
+
+		@Override
+		public void forEachProxyFactory(HttpServiceGroupConfigurer.ProxyFactoryCallback configurer) {
+
+		}
+
+		@Override
+		public void forEachGroup(HttpServiceGroupConfigurer.GroupCallback<WebClient.Builder> groupConfigurer) {
+			groupConfigurer.withGroup(
+					new TestGroup(GROUP_NAME, HttpServiceGroup.ClientType.WEB_CLIENT, new HashSet<>()), builder,
+					HttpServiceProxyFactory.builder());
+		}
+
+	}
+
+	private record TestGroup(String name, ClientType clientType,
+			Set<Class<?>> httpServiceTypes) implements HttpServiceGroup {
+
+	}
+
+}

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/reactive/ReactorLoadBalancerClientAutoConfigurationTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -23,19 +23,24 @@ import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.autoconfigure.http.client.reactive.service.ReactiveHttpClientServiceProperties;
 import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.cloud.client.ServiceInstance;
 import org.springframework.cloud.client.loadbalancer.LoadBalanced;
 import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryFactory;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerClientsProperties;
 import org.springframework.cloud.client.loadbalancer.LoadBalancerProperties;
+import org.springframework.cloud.client.loadbalancer.LoadBalancerRestClientHttpServiceGroupConfigurer;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.web.reactive.function.client.WebClient;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.BDDAssertions.then;
 import static org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerTestUtils.assertLoadBalanced;
 import static org.springframework.cloud.client.loadbalancer.reactive.LoadBalancerTestUtils.getFilters;
@@ -150,6 +155,18 @@ public class ReactorLoadBalancerClientAutoConfigurationTests {
 		then(clientProperties.getHealthCheck().getInterval()).isEqualTo(Duration.ofSeconds(30));
 	}
 
+	@Test
+	void loadBalancerRestClientHttpServiceGroupConfigurerPresent() {
+		new ApplicationContextRunner()
+			.withConfiguration(AutoConfigurations.of(ReactorLoadBalancerClientAutoConfiguration.class,
+					LoadBalancerBeanPostProcessorAutoConfiguration.class))
+			.withUserConfiguration(OneWebClientBuilder.class)
+			.run(context -> {
+				assertThat(context.getBeansOfType(LoadBalancerWebClientHttpServiceGroupConfigurer.class)).hasSize(1);
+				assertThat(context.getBeansOfType(LoadBalancerRestClientHttpServiceGroupConfigurer.class)).hasSize(0);
+			});
+	}
+
 	private ConfigurableApplicationContext init(Class<?> config) {
 		return LoadBalancerTestUtils.init(config, ReactorLoadBalancerClientAutoConfiguration.class,
 				LoadBalancerBeanPostProcessorAutoConfiguration.class);
@@ -211,6 +228,11 @@ public class ReactorLoadBalancerClientAutoConfigurationTests {
 			return new TestService(loadBalancedWebClientBuilder());
 		}
 
+		@Bean
+		ReactiveHttpClientServiceProperties reactiveHttpClientServiceProperties() {
+			return new ReactiveHttpClientServiceProperties();
+		}
+
 		private static final class TestService {
 
 			public final WebClient webClient;

spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/reactive/RetryableLoadBalancerExchangeFilterFunctionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -31,6 +31,7 @@ import org.springframework.cloud.client.loadbalancer.LoadBalancerProperties;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.web.reactive.function.client.ClientRequest;
 import org.springframework.web.reactive.function.client.ClientResponse;
 import org.springframework.web.reactive.function.client.ExchangeFunction;
@@ -75,7 +76,7 @@ class RetryableLoadBalancerExchangeFilterFunctionTests {
 		when(factory.getInstance("test")).thenReturn(new TestReactiveLoadBalancer());
 		when(factory.getProperties(any())).thenReturn(properties);
 		when(clientRequest.headers()).thenReturn(new HttpHeaders());
-		when(clientRequest.cookies()).thenReturn(new HttpHeaders());
+		when(clientRequest.cookies()).thenReturn(new LinkedMultiValueMap<>());
 
 	}
 

spring-cloud-commons/src/test/java/org/springframework/cloud/configuration/SpringBootDependencyTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -27,6 +27,7 @@ import static org.assertj.core.api.BDDAssertions.then;
 
 /**
  * @author Marcin Grzejszczak
+ * @author Olga Maciaszek-Sharma
  */
 public class SpringBootDependencyTests {
 
@@ -176,8 +177,8 @@ public class SpringBootDependencyTests {
 	@Test
 	public void should_match_against_current_manifest() {
 		try {
-			verifyCurrentVersionFromManifest("3.5");
-			verifyCurrentVersionFromManifest("3.5.x");
+			verifyCurrentVersionFromManifest("4.0");
+			verifyCurrentVersionFromManifest("4.0.x");
 		}
 		catch (AssertionError e) {
 			// if (e.getMessage() != null && e.getMessage().contains("3.3.")) {
@@ -204,7 +205,7 @@ public class SpringBootDependencyTests {
 
 	@Test
 	public void should_match_against_current_predicate() {
-		List<String> acceptedVersions = Collections.singletonList("3.0");
+		List<String> acceptedVersions = Collections.singletonList("4.0");
 		SpringBootVersionVerifier versionVerifier = new SpringBootVersionVerifier(acceptedVersions) {
 			@Override
 			String getVersionFromManifest() {
@@ -212,7 +213,7 @@ public class SpringBootDependencyTests {
 			}
 		};
 		versionVerifier.ACCEPTED_VERSIONS.clear();
-		versionVerifier.ACCEPTED_VERSIONS.put("3.0", versionVerifier.is3_5());
+		versionVerifier.ACCEPTED_VERSIONS.put("4.0", versionVerifier.is4_0());
 
 		VerificationResult verificationResult = versionVerifier.verify();
 
@@ -222,7 +223,7 @@ public class SpringBootDependencyTests {
 
 	@Test
 	public void should_match_against_current_predicate_with_version_ending_with_x() {
-		List<String> acceptedVersions = Collections.singletonList("3.0.x");
+		List<String> acceptedVersions = Collections.singletonList("4.0.x");
 		SpringBootVersionVerifier versionVerifier = new SpringBootVersionVerifier(acceptedVersions) {
 			@Override
 			String getVersionFromManifest() {
@@ -230,7 +231,7 @@ public class SpringBootDependencyTests {
 			}
 		};
 		versionVerifier.ACCEPTED_VERSIONS.clear();
-		versionVerifier.ACCEPTED_VERSIONS.put("3.0", versionVerifier.is3_5());
+		versionVerifier.ACCEPTED_VERSIONS.put("4.0", versionVerifier.is4_0());
 
 		VerificationResult verificationResult = versionVerifier.verify();
 

spring-cloud-context-integration-tests/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-context-integration-tests</artifactId>

spring-cloud-context-webflux-integration-tests/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-context-webflux-integration-tests</artifactId>

spring-cloud-context/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-context</artifactId>

spring-cloud-loadbalancer/pom.xml

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-loadbalancer</artifactId>

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2023 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -380,9 +380,10 @@ public final class ServiceInstanceListSupplierBuilder {
 		return new HealthCheckServiceInstanceListSupplier(delegate, loadBalancerClientFactory,
 				(serviceInstance, healthCheckPath) -> webClient.get()
 					.uri(UriComponentsBuilder.fromUriString(getUri(serviceInstance, healthCheckPath)).build().toUri())
-					.exchange()
-					.flatMap(clientResponse -> clientResponse.releaseBody()
-						.thenReturn(HttpStatus.OK.equals(clientResponse.statusCode()))));
+					.retrieve()
+					.toBodilessEntity()
+					.map(response -> HttpStatus.OK.equals(response.getStatusCode()))
+					.onErrorReturn(false));
 	}
 
 	private ServiceInstanceListSupplier blockingHealthCheckServiceInstanceListSupplier(RestTemplate restTemplate,

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/blocking/XForwardedHeadersTransformerTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -65,9 +65,9 @@ class XForwardedHeadersTransformerTests {
 
 		HttpRequest newRequest = transformer.transformRequest(request, serviceInstance);
 
-		assertThat(newRequest.getHeaders()).containsKey("X-Forwarded-Host");
+		assertThat(newRequest.getHeaders().containsHeader("X-Forwarded-Host")).isTrue();
 		assertThat(newRequest.getHeaders().getFirst("X-Forwarded-Host")).isEqualTo("google.com");
-		assertThat(newRequest.getHeaders()).containsKey("X-Forwarded-Proto");
+		assertThat(newRequest.getHeaders().containsHeader("X-Forwarded-Proto")).isTrue();
 		assertThat(newRequest.getHeaders().getFirst("X-Forwarded-Proto")).isEqualTo("https");
 	}
 
@@ -78,8 +78,8 @@ class XForwardedHeadersTransformerTests {
 		XForwardedHeadersTransformer transformer = new XForwardedHeadersTransformer(loadBalancerClientFactory);
 
 		HttpRequest newRequest = transformer.transformRequest(request, serviceInstance);
-		assertThat(newRequest.getHeaders()).doesNotContainKey("X-Forwarded-Host");
-		assertThat(newRequest.getHeaders()).doesNotContainKey("X-Forwarded-Proto");
+		assertThat(newRequest.getHeaders().containsHeader("X-Forwarded-Host")).isFalse();
+		assertThat(newRequest.getHeaders().containsHeader("X-Forwarded-Proto")).isFalse();
 	}
 
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2023 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -703,7 +703,7 @@ class HealthCheckServiceInstanceListSupplierTests {
 	}
 
 	@Test
-	void shouldCheckUseProvidedPortForHealthCheckRequest() {
+	void shouldCheckUserProvidedPortForHealthCheckRequest() {
 		Throwable exception = catchThrowable(() -> {
 			String serviceId = "ignored-service";
 			properties.getHealthCheck().setPort(8888);
@@ -718,7 +718,7 @@ class HealthCheckServiceInstanceListSupplierTests {
 			listSupplier.isAlive(serviceInstance).block();
 		});
 
-		assertThat(exception).hasMessageContaining("Connection refused: /127.0.0.1:888");
+		assertThat(exception).hasMessageContaining("Connection refused: /127.0.0.1:8888");
 	}
 
 	private static Stream<Arguments> healthCheckFunctions() {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -74,7 +74,7 @@ class LoadBalancerServiceInstanceCookieTransformerTests {
 	void shouldReturnPassedRequestWhenNoServiceInstance() {
 		HttpRequest newRequest = transformer.transformRequest(request, null);
 
-		assertThat(newRequest.getHeaders()).doesNotContainKey(HttpHeaders.COOKIE);
+		assertThat(newRequest.getHeaders().containsHeader(HttpHeaders.COOKIE)).isFalse();
 	}
 
 	@Test
@@ -82,7 +82,7 @@ class LoadBalancerServiceInstanceCookieTransformerTests {
 		properties.getStickySession().setInstanceIdCookieName(null);
 		HttpRequest newRequest = transformer.transformRequest(request, serviceInstance);
 
-		assertThat(newRequest.getHeaders()).doesNotContainKey(HttpHeaders.COOKIE);
+		assertThat(newRequest.getHeaders().containsHeader(HttpHeaders.COOKIE)).isFalse();
 	}
 
 	@Test
@@ -90,7 +90,7 @@ class LoadBalancerServiceInstanceCookieTransformerTests {
 		properties.getStickySession().setInstanceIdCookieName("");
 		HttpRequest newRequest = transformer.transformRequest(request, serviceInstance);
 
-		assertThat(newRequest.getHeaders()).doesNotContainKey(HttpHeaders.COOKIE);
+		assertThat(newRequest.getHeaders().containsHeader(HttpHeaders.COOKIE)).isFalse();
 
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -17,6 +17,7 @@
 package org.springframework.cloud.loadbalancer.core;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import org.junit.jupiter.api.BeforeEach;
@@ -31,7 +32,8 @@ import org.springframework.cloud.client.loadbalancer.LoadBalancerProperties;
 import org.springframework.cloud.client.loadbalancer.Request;
 import org.springframework.cloud.client.loadbalancer.RequestData;
 import org.springframework.cloud.client.loadbalancer.RequestDataContext;
-import org.springframework.http.HttpHeaders;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
 import org.springframework.web.reactive.function.client.ClientRequest;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -72,8 +74,8 @@ class RequestBasedStickySessionServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldReturnInstanceBasedOnCookieFromClientRequest() {
-		HttpHeaders headers = new HttpHeaders();
-		headers.add(properties.getStickySession().getInstanceIdCookieName(), "test-1");
+		MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
+		headers.put(properties.getStickySession().getInstanceIdCookieName(), Collections.singletonList("test-1"));
 		when(clientRequest.cookies()).thenReturn(headers);
 		Request<RequestDataContext> request = new DefaultRequest<>(
 				new RequestDataContext(new RequestData(clientRequest)));
@@ -86,8 +88,8 @@ class RequestBasedStickySessionServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldReturnAllDelegateInstancesIfInstanceBasedOnCookieFromClientRequestNotFound() {
-		HttpHeaders headers = new HttpHeaders();
-		headers.add(properties.getStickySession().getInstanceIdCookieName(), "test-4");
+		MultiValueMap<String, String> headers = new LinkedMultiValueMap<>();
+		headers.put(properties.getStickySession().getInstanceIdCookieName(), Collections.singletonList("test-4"));
 		when(clientRequest.cookies()).thenReturn(headers);
 		Request<RequestDataContext> request = new DefaultRequest<>(
 				new RequestDataContext(new RequestData(clientRequest)));
@@ -99,7 +101,7 @@ class RequestBasedStickySessionServiceInstanceListSupplierTests {
 
 	@Test
 	void shouldReturnAllInstancesFromDelegateIfClientRequestHasNoCookie() {
-		when(clientRequest.cookies()).thenReturn(new HttpHeaders());
+		when(clientRequest.cookies()).thenReturn(new LinkedMultiValueMap<>());
 		Request<RequestDataContext> request = new DefaultRequest<>(
 				new RequestDataContext(new RequestData(clientRequest)));
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2023 the original author or authors.
+ * Copyright 2013-2025 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.
@@ -26,6 +26,7 @@ import org.springframework.http.HttpStatus;
 import org.springframework.web.client.RestClient;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.reactive.function.client.WebClient;
+import org.springframework.web.reactive.function.client.WebClientRequestException;
 import org.springframework.web.util.UriComponentsBuilder;
 
 import static org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplierBuilder.getUri;
@@ -46,9 +47,10 @@ final class ServiceInstanceListSuppliersTestUtils {
 	static BiFunction<ServiceInstance, String, Mono<Boolean>> healthCheckFunction(WebClient webClient) {
 		return (serviceInstance, healthCheckPath) -> webClient.get()
 			.uri(UriComponentsBuilder.fromUriString(getUri(serviceInstance, healthCheckPath)).build().toUri())
-			.exchange()
-			.flatMap(clientResponse -> clientResponse.releaseBody()
-				.thenReturn(HttpStatus.OK.equals(clientResponse.statusCode())));
+			.retrieve()
+			.toBodilessEntity()
+			.map(response -> HttpStatus.OK.equals(response.getStatusCode()))
+			.onErrorReturn(throwable -> !(throwable instanceof WebClientRequestException), false);
 	}
 
 	static BiFunction<ServiceInstance, String, Mono<Boolean>> healthCheckFunction(RestTemplate restTemplate) {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2021 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -66,9 +66,9 @@ class XForwardedHeadersTransformerTests {
 
 		ClientRequest newRequest = transformer.transformRequest(request, serviceInstance);
 
-		assertThat(newRequest.headers()).containsKey("X-Forwarded-Host");
+		assertThat(newRequest.headers().containsHeader("X-Forwarded-Host")).isTrue();
 		assertThat(newRequest.headers().getFirst("X-Forwarded-Host")).isEqualTo("spring.io");
-		assertThat(newRequest.headers()).containsKey("X-Forwarded-Proto");
+		assertThat(newRequest.headers().containsHeader("X-Forwarded-Proto")).isTrue();
 		assertThat(newRequest.headers().getFirst("X-Forwarded-Proto")).isEqualTo("https");
 	}
 
@@ -79,8 +79,8 @@ class XForwardedHeadersTransformerTests {
 
 		ClientRequest newRequest = transformer.transformRequest(request, serviceInstance);
 
-		assertThat(newRequest.headers()).doesNotContainKey("X-Forwarded-Host");
-		assertThat(newRequest.headers()).doesNotContainKey("X-Forwarded-Proto");
+		assertThat(newRequest.headers().containsHeader("X-Forwarded-Host")).isFalse();
+		assertThat(newRequest.headers().containsHeader("X-Forwarded-Proto")).isFalse();
 	}
 
 }

spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/stats/MicrometerStatsLoadBalancerLifecycleTests.java

@@ -44,6 +44,7 @@ import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalanc
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
+import org.springframework.util.LinkedMultiValueMap;
 import org.springframework.util.MultiValueMapAdapter;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -71,7 +72,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 	@Test
 	void shouldRecordSuccessfulTimedRequest() {
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test"), new HttpHeaders(),
-				new HttpHeaders(), new HashMap<>());
+				new LinkedMultiValueMap<>(), new HashMap<>());
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		Response<ServiceInstance> lbResponse = new DefaultResponse(
 				new DefaultServiceInstance("test-1", "test", "test.org", 8080, false, new HashMap<>()));
@@ -93,6 +94,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 				Tag.of("serviceInstance.port", "8080"), Tag.of("status", "200"), Tag.of("uri", "/test"));
 	}
 
+	@SuppressWarnings("unchecked")
 	@Test
 	void shouldNotAddPathValueWhenDisabled() {
 		ReactiveLoadBalancer.Factory<ServiceInstance> factory = mock(ReactiveLoadBalancer.Factory.class);
@@ -102,7 +104,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 		MicrometerStatsLoadBalancerLifecycle statsLifecycle = new MicrometerStatsLoadBalancerLifecycle(meterRegistry,
 				factory);
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test"), new HttpHeaders(),
-				new HttpHeaders(), new HashMap<>());
+				new LinkedMultiValueMap<>(), new HashMap<>());
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		Response<ServiceInstance> lbResponse = new DefaultResponse(
 				new DefaultServiceInstance("test-1", "test", "test.org", 8080, false, new HashMap<>()));
@@ -126,7 +128,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 		String uriTemplate = "/test/{pathParam}/test";
 		attributes.put(attributeName, uriTemplate);
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test/123/test"),
-				new HttpHeaders(), new HttpHeaders(), attributes);
+				new HttpHeaders(), new LinkedMultiValueMap<>(), attributes);
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		Response<ServiceInstance> lbResponse = new DefaultResponse(
 				new DefaultServiceInstance("test-1", "test", "test.org", 8080, false, new HashMap<>()));
@@ -152,7 +154,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 	@Test
 	void shouldRecordFailedTimedRequest() {
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test"), new HttpHeaders(),
-				new HttpHeaders(), new HashMap<>());
+				new LinkedMultiValueMap<>(), new HashMap<>());
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		Response<ServiceInstance> lbResponse = new DefaultResponse(
 				new DefaultServiceInstance("test-1", "test", "test.org", 8080, false, new HashMap<>()));
@@ -175,7 +177,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 	@Test
 	void shouldNotRecordDiscardedRequest() {
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test"), new HttpHeaders(),
-				new HttpHeaders(), new HashMap<>());
+				new LinkedMultiValueMap<>(), new HashMap<>());
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		Response<ServiceInstance> lbResponse = new EmptyResponse();
 		statsLifecycle.onStartRequest(lbRequest, lbResponse);
@@ -247,7 +249,7 @@ class MicrometerStatsLoadBalancerLifecycleTests {
 	@Test
 	void shouldHandleNullLoadBalancerResponse() {
 		RequestData requestData = new RequestData(HttpMethod.GET, URI.create("http://test.org/test"), new HttpHeaders(),
-				new HttpHeaders(), new HashMap<>());
+				new LinkedMultiValueMap<>(), new HashMap<>());
 		Request<Object> lbRequest = new DefaultRequest<>(new RequestDataContext(requestData));
 		assertThatCode(() -> {
 			statsLifecycle.onStartRequest(lbRequest, null);

spring-cloud-starter-bootstrap/pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<packaging>jar</packaging>

spring-cloud-starter-loadbalancer/pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<modelVersion>4.0.0</modelVersion>

spring-cloud-starter/pom.xml

@@ -6,7 +6,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 	</parent>
 	<artifactId>spring-cloud-starter</artifactId>
 	<name>spring-cloud-starter</name>

spring-cloud-test-support/pom.xml

@@ -7,7 +7,7 @@
 	<parent>
 		<groupId>org.springframework.cloud</groupId>
 		<artifactId>spring-cloud-commons-parent</artifactId>
-		<version>4.3.1-SNAPSHOT</version>
+		<version>5.0.0-SNAPSHOT</version>
 		<relativePath>..</relativePath>
 	</parent>
 	<artifactId>spring-cloud-test-support</artifactId>