Revert making RestClient the default Eureka client. Fixes gh-4380.

docs/modules/ROOT/pages/spring-cloud-netflix.adoc

@@ -277,9 +277,13 @@ It is initialized in a `SmartLifecycle` (with `phase=0`), so the earliest you ca
 
 `EurekaClient` uses either `RestClient`, `RestTemplate`, `WebClient` or `JerseyClient` under the hood. In order to use the `EurekaClient`, you need to have one of the supported HTTP clients on your classpath.
 
-To use `RestTemplate` or `RestClient`, add `spring-boot-starter-web` to your dependencies. To use `WebClient`, add `spring-boot-starter-webflux` to your dependencies. If both `spring-boot-starter-web` and `spring-boot-starter-webflux` are included in the dependencies and the `eureka.client.webclient.enabled` flag is set to `true`, then `WebClient` will be used. If that's not the case and `eureka.client.restclient.enabled` is set to false, the `RestTemplate` will be used. Otherwise, the `RestClient` will be used.
+To use `RestTemplate` or `RestClient`, add `spring-boot-starter-web` to your dependencies. To use `WebClient`, add `spring-boot-starter-webflux` to your dependencies. If both `spring-boot-starter-web`
+and `spring-boot-starter-webflux` are included in the dependencies and the `eureka.client.webclient.enabled` flag is set to `true`,
+then `WebClient` will be used. If that's not the case and `eureka.client.restclient.enabled` is set to `true`, `RestClient` will be used. Otherwise, `RestTemplate` will be used.
 
-NOTE: Starting from 4.2.0, the default client has changed to `RestClient`.
+NOTE: For any of those client implementations, if there's a builder bean available, it will be used to create the underlying client.
+
+NOTE: We're planning on changing the default client to `RestClient` with the next major release.
 
 If you wish to use Jersey instead, you need to add the Jersey dependencies to your classpath.
 The following example shows the dependencies you need to add:

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/config/DiscoveryClientOptionalArgsConfiguration.java

@@ -282,7 +282,8 @@ static class OnWebClientDisabled {
 
 		}
 
-		@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "false")
+		@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "false",
+				matchIfMissing = true)
 		static class OnRestClientDisabled {
 
 		}
@@ -311,8 +312,7 @@ static class OnWebClientDisabled {
 
 		}
 
-		@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", matchIfMissing = true,
-				havingValue = "true")
+		@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "true")
 		static class OnRestClientEnabled {
 
 		}

spring-cloud-netflix-eureka-client/src/main/java/org/springframework/cloud/netflix/eureka/config/EurekaConfigServerBootstrapConfiguration.java

@@ -129,7 +129,8 @@ static class OnWebClientDisabled {
 
 			}
 
-			@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "false")
+			@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "false",
+					matchIfMissing = true)
 			static class OnRestClientDisabled {
 
 			}
@@ -194,8 +195,7 @@ static class OnWebClientDisabled {
 
 			}
 
-			@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", matchIfMissing = true,
-					havingValue = "true")
+			@ConditionalOnProperty(prefix = "eureka.client", name = "restclient.enabled", havingValue = "true")
 			static class OnRestClientEnabled {
 
 			}

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/config/EurekaConfigServerBootstrapConfigurationTests.java

@@ -39,7 +39,7 @@
 import org.springframework.cloud.config.client.ConfigServerInstanceProvider;
 import org.springframework.cloud.netflix.eureka.CloudEurekaClient;
 import org.springframework.cloud.netflix.eureka.EurekaClientConfigBean;
-import org.springframework.cloud.netflix.eureka.http.RestClientEurekaHttpClient;
+import org.springframework.cloud.netflix.eureka.http.RestTemplateEurekaHttpClient;
 import org.springframework.cloud.test.ClassPathExclusions;
 import org.springframework.cloud.test.ModifiedClassPathRunner;
 import org.springframework.context.annotation.Bean;
@@ -53,6 +53,7 @@
  * @author Spencer Gibb
  * @author Tang Xiong
  */
+@SuppressWarnings("removal")
 @RunWith(ModifiedClassPathRunner.class)
 @ClassPathExclusions("spring-webflux-*")
 public class EurekaConfigServerBootstrapConfigurationTests {
@@ -205,7 +206,7 @@ public void eurekaConfigServerInstanceProviderCalledWithVipAddress() {
 
 	private void assertEurekaBeansPresent(AssertableApplicationContext context) {
 		assertThat(context).hasSingleBean(EurekaClientConfigBean.class);
-		assertThat(context).hasSingleBean(RestClientEurekaHttpClient.class);
+		assertThat(context).hasSingleBean(RestTemplateEurekaHttpClient.class);
 		assertThat(context).hasSingleBean(ConfigServerInstanceProvider.Function.class);
 	}
 

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/config/EurekaConfigServerBootstrapConfigurationWebClientTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2013-2022 the original author or authors.
+ * Copyright 2013-2024 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.
@@ -22,14 +22,15 @@
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.cloud.config.client.ConfigServerInstanceProvider;
 import org.springframework.cloud.netflix.eureka.EurekaClientConfigBean;
-import org.springframework.cloud.netflix.eureka.http.RestClientEurekaHttpClient;
+import org.springframework.cloud.netflix.eureka.http.RestTemplateEurekaHttpClient;
 import org.springframework.cloud.netflix.eureka.http.WebClientEurekaHttpClient;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author Spencer Gibb
  */
+@SuppressWarnings("removal")
 class EurekaConfigServerBootstrapConfigurationWebClientTests {
 
 	@Test
@@ -53,7 +54,7 @@ void properBeansCreatedWhenEnabledWebClientDisabled() {
 			.run(context -> {
 				assertThat(context).hasSingleBean(EurekaClientConfigBean.class);
 				assertThat(context).doesNotHaveBean(WebClientEurekaHttpClient.class);
-				assertThat(context).hasSingleBean(RestClientEurekaHttpClient.class);
+				assertThat(context).hasSingleBean(RestTemplateEurekaHttpClient.class);
 				assertThat(context).hasSingleBean(ConfigServerInstanceProvider.Function.class);
 			});
 	}

spring-cloud-netflix-eureka-client/src/test/java/org/springframework/cloud/netflix/eureka/config/JerseyClientOptionalArgsConfigurationTests.java

@@ -21,7 +21,7 @@
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
-import org.springframework.cloud.netflix.eureka.http.RestClientDiscoveryClientOptionalArgs;
+import org.springframework.cloud.netflix.eureka.http.RestTemplateDiscoveryClientOptionalArgs;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -30,11 +30,12 @@
  *
  * @author Olga Maciaszek-Sharma
  */
+@SuppressWarnings("deprecation")
 public class JerseyClientOptionalArgsConfigurationTests {
 
 	@SuppressWarnings("OptionalGetWithoutIsPresent")
 	@Test
-	void shouldCreateRestClientDiscoveryClientOptionalArgsWhenJerseyClientDisabled() {
+	void shouldCreateRestTemplateDiscoveryClientOptionalArgsWhenJerseyClientDisabled() {
 		new ApplicationContextRunner()
 			.withConfiguration(AutoConfigurations.of(DiscoveryClientOptionalArgsConfiguration.class))
 			.withPropertyValues("eureka.client.jersey.enabled=false")
@@ -44,8 +45,8 @@ void shouldCreateRestClientDiscoveryClientOptionalArgsWhenJerseyClientDisabled()
 					.values()
 					.stream()
 					.findFirst()
-					.get()).isInstanceOf(RestClientDiscoveryClientOptionalArgs.class);
-				assertThat(context).hasSingleBean(RestClientDiscoveryClientOptionalArgs.class);
+					.get()).isInstanceOf(RestTemplateDiscoveryClientOptionalArgs.class);
+				assertThat(context).hasSingleBean(RestTemplateDiscoveryClientOptionalArgs.class);
 			});
 	}