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OlgaMaciaszekOlgaMaciaszek
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Allow building @LoadBalanced RestClient in component constructor. (#1339)
1 parent b5abbf6 commit 5b5bf58

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-46
lines changed

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

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/*
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* Copyright 2012-2024 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.springframework.cloud.client.loadbalancer;
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import org.springframework.http.client.ClientHttpRequestInterceptor;
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/**
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* A marker interface for {@link ClientHttpRequestInterceptor} instances used for
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* load-balancing.
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*
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* @author Olga Maciaszek-Sharma
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* @since 4.1.2
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*/
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public interface BlockingLoadBalancerInterceptor extends ClientHttpRequestInterceptor {
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}

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

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/*
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* Copyright 2012-2024 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.springframework.cloud.client.loadbalancer;
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import java.io.IOException;
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import org.springframework.beans.factory.ObjectProvider;
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import org.springframework.http.HttpRequest;
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import org.springframework.http.client.ClientHttpRequestExecution;
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import org.springframework.http.client.ClientHttpRequestInterceptor;
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import org.springframework.http.client.ClientHttpResponse;
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/**
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* An {@link ClientHttpRequestInterceptor} implementation that uses {@link ObjectProvider}
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* to resolve appropriate {@link BlockingLoadBalancerInterceptor} delegate when the
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* {@link ClientHttpRequestInterceptor#intercept(HttpRequest, byte[], ClientHttpRequestExecution)}
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* method is first called.
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*
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* @author Olga Maciaszek-Sharma
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* @since 4.1.2
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*/
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public class DeferringLoadBalancerInterceptor implements ClientHttpRequestInterceptor {
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private final ObjectProvider<BlockingLoadBalancerInterceptor> loadBalancerInterceptorProvider;
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private BlockingLoadBalancerInterceptor delegate;
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public DeferringLoadBalancerInterceptor(
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ObjectProvider<BlockingLoadBalancerInterceptor> loadBalancerInterceptorProvider) {
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this.loadBalancerInterceptorProvider = loadBalancerInterceptorProvider;
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}
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@Override
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public ClientHttpResponse intercept(HttpRequest request, byte[] body, ClientHttpRequestExecution execution)
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throws IOException {
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tryResolveDelegate();
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return delegate.intercept(request, body, execution);
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}
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private void tryResolveDelegate() {
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if (delegate == null) {
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delegate = loadBalancerInterceptorProvider.getIfAvailable();
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if (delegate == null) {
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throw new IllegalStateException("LoadBalancer interceptor not available.");
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}
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}
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}
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// Visible for tests
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ObjectProvider<BlockingLoadBalancerInterceptor> getLoadBalancerInterceptorProvider() {
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return loadBalancerInterceptorProvider;
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}
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}

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

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@@ -33,12 +33,12 @@
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import org.springframework.boot.context.properties.EnableConfigurationProperties;
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import org.springframework.cloud.client.ServiceInstance;
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import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
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import org.springframework.context.ApplicationContext;
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import org.springframework.context.annotation.Bean;
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import org.springframework.context.annotation.Conditional;
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import org.springframework.context.annotation.Configuration;
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import org.springframework.http.client.ClientHttpRequestInterceptor;
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import org.springframework.retry.support.RetryTemplate;
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import org.springframework.web.client.RestClient;
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import org.springframework.web.client.RestTemplate;
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/**
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@Autowired(required = false)
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private List<RestTemplate> restTemplates = Collections.emptyList();
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@LoadBalanced
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@Autowired(required = false)
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private List<RestClient.Builder> restClientBuilders = Collections.emptyList();
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@Autowired(required = false)
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private List<LoadBalancerRequestTransformer> transformers = Collections.emptyList();
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@@ -79,26 +75,33 @@ public SmartInitializingSingleton loadBalancedRestTemplateInitializerDeprecated(
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});
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}
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@Bean
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public SmartInitializingSingleton loadBalancedRestClientBuilderInitializer(
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ObjectProvider<List<RestClientBuilderCustomizer>> restClientBuilderCustomizers) {
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return () -> restClientBuilderCustomizers.ifAvailable(customizers -> {
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for (RestClient.Builder restClientBuilder : restClientBuilders) {
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for (RestClientBuilderCustomizer customizer : customizers) {
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customizer.customize(restClientBuilder);
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}
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}
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});
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}
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@Bean
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@ConditionalOnMissingBean
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public LoadBalancerRequestFactory loadBalancerRequestFactory(LoadBalancerClient loadBalancerClient) {
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return new LoadBalancerRequestFactory(loadBalancerClient, transformers);
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}
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@Configuration(proxyBeanMethods = false)
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@AutoConfiguration
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static class DeferringLoadBalancerInterceptorConfig {
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@Bean
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@ConditionalOnMissingBean
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public DeferringLoadBalancerInterceptor deferringLoadBalancerInterceptor(
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ObjectProvider<BlockingLoadBalancerInterceptor> loadBalancerInterceptorObjectProvider) {
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return new DeferringLoadBalancerInterceptor(loadBalancerInterceptorObjectProvider);
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}
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@Bean
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@ConditionalOnBean(DeferringLoadBalancerInterceptor.class)
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@ConditionalOnMissingBean
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LoadBalancerRestClientBuilderBeanPostProcessor lbRestClientPostProcessor(
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DeferringLoadBalancerInterceptor loadBalancerInterceptor, ApplicationContext context) {
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return new LoadBalancerRestClientBuilderBeanPostProcessor(loadBalancerInterceptor, context);
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}
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}
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@AutoConfiguration
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@Conditional(RetryMissingOrDisabledCondition.class)
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static class LoadBalancerInterceptorConfig {
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@@ -118,13 +121,6 @@ public RestTemplateCustomizer restTemplateCustomizer(LoadBalancerInterceptor loa
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};
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}
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@Bean
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@ConditionalOnMissingBean
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public RestClientBuilderCustomizer restClientBuilderCustomizer(
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LoadBalancerInterceptor loadBalancerInterceptor) {
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return restClientBuilder -> restClientBuilder.requestInterceptor(loadBalancerInterceptor);
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}
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128124
}
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130126
private static class RetryMissingOrDisabledCondition extends AnyNestedCondition {
@@ -148,7 +144,7 @@ static class RetryDisabled {
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/**
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* Auto configuration for retry mechanism.
150146
*/
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@Configuration(proxyBeanMethods = false)
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@AutoConfiguration
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@ConditionalOnClass(RetryTemplate.class)
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public static class RetryAutoConfiguration {
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};
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}
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@Bean
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@ConditionalOnMissingBean
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public RestClientBuilderCustomizer restClientBuilderCustomizer(
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RetryLoadBalancerInterceptor loadBalancerInterceptor) {
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return restClientBuilder -> restClientBuilder.requestInterceptor(loadBalancerInterceptor);
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}
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}
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}

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

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import org.springframework.http.HttpRequest;
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import org.springframework.http.client.ClientHttpRequestExecution;
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import org.springframework.http.client.ClientHttpRequestInterceptor;
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import org.springframework.http.client.ClientHttpResponse;
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import org.springframework.util.Assert;
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* @author Ryan Baxter
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* @author William Tran
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*/
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public class LoadBalancerInterceptor implements ClientHttpRequestInterceptor {
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public class LoadBalancerInterceptor implements BlockingLoadBalancerInterceptor {
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private final LoadBalancerClient loadBalancer;
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‎spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/LoadBalancerRestClientBuilderBeanPostProcessor.java‎

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*
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* @author Olga Maciaszek-Sharma
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* @since 4.1.0
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* @deprecated to be removed in the next release.
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*/
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@Deprecated(forRemoval = true)
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public class LoadBalancerRestClientBuilderBeanPostProcessor implements BeanPostProcessor {
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private final ClientHttpRequestInterceptor loadBalancerInterceptor;

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

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*
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* @author Olga Maciaszek-Sharma
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* @since 4.1.1
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* @deprecated to be removed in the next major release.
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*/
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@Deprecated(forRemoval = true)
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public interface RestClientBuilderCustomizer {
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void customize(RestClient.Builder restClientBuilder);

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

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/*
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* Copyright 2012-2020 the original author or authors.
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* Copyright 2012-2024 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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import org.springframework.cloud.client.loadbalancer.reactive.ReactiveLoadBalancer;
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import org.springframework.http.HttpRequest;
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import org.springframework.http.client.ClientHttpRequestExecution;
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import org.springframework.http.client.ClientHttpRequestInterceptor;
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import org.springframework.http.client.ClientHttpResponse;
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import org.springframework.retry.RetryListener;
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import org.springframework.retry.backoff.BackOffPolicy;
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* @author Olga Maciaszek-Sharma
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*/
4746
@SuppressWarnings({ "unchecked", "rawtypes" })
48-
public class RetryLoadBalancerInterceptor implements ClientHttpRequestInterceptor {
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public class RetryLoadBalancerInterceptor implements BlockingLoadBalancerInterceptor {
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5049
private static final Log LOG = LogFactory.getLog(RetryLoadBalancerInterceptor.class);
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‎spring-cloud-commons/src/test/java/org/springframework/cloud/client/loadbalancer/LoadBalancedRestClientIntegrationTests.java‎

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/*
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* Copyright 2012-2024 the original author or authors.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
6+
* You may obtain a copy of the License at
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*
8+
* https://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.springframework.cloud.client.loadbalancer;
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import java.io.IOException;
20+
import java.net.URI;
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import org.junit.jupiter.api.Test;
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import org.springframework.beans.factory.annotation.Autowired;
25+
import org.springframework.boot.SpringBootConfiguration;
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import org.springframework.boot.test.context.SpringBootTest;
27+
import org.springframework.cloud.client.ServiceInstance;
28+
import org.springframework.context.ApplicationContext;
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import org.springframework.context.annotation.Bean;
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import org.springframework.web.client.RestClient;
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import static org.assertj.core.api.Assertions.assertThatThrownBy;
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/**
35+
* Integration tests for load-balanced {@link RestClient}.
36+
*
37+
* @author Olga Maciaszek-Sharma
38+
*/
39+
@SpringBootTest(
40+
classes = { LoadBalancedRestClientIntegrationTests.TestConfig.class, LoadBalancerAutoConfiguration.class },
41+
properties = "spring.cloud.loadbalancer.retry.enabled=false")
42+
public class LoadBalancedRestClientIntegrationTests {
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private final RestClient client;
45+
46+
@Autowired
47+
ApplicationContext context;
48+
49+
public LoadBalancedRestClientIntegrationTests(@Autowired RestClient.Builder clientBuilder) {
50+
this.client = clientBuilder.build();
51+
}
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@Test
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void shouldBuildLoadBalancedRestClientInConstructor() {
55+
// Interceptors are not visible in RestClient
56+
assertThatThrownBy(() -> client.get().uri("http://test-service").retrieve())
57+
.hasMessage("LoadBalancerInterceptor invoked.");
58+
}
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60+
@SpringBootConfiguration
61+
static class TestConfig {
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@LoadBalanced
64+
@Bean
65+
RestClient.Builder restClientBuilder() {
66+
return RestClient.builder();
67+
}
68+
69+
@Bean
70+
LoadBalancerClient testLoadBalancerClient() {
71+
return new LoadBalancerClient() {
72+
@Override
73+
public <T> T execute(String serviceId, LoadBalancerRequest<T> request) throws IOException {
74+
throw new UnsupportedOperationException("LoadBalancerInterceptor invoked.");
75+
}
76+
77+
@Override
78+
public <T> T execute(String serviceId, ServiceInstance serviceInstance, LoadBalancerRequest<T> request)
79+
throws IOException {
80+
throw new UnsupportedOperationException("LoadBalancerInterceptor invoked.");
81+
}
82+
83+
@Override
84+
public URI reconstructURI(ServiceInstance instance, URI original) {
85+
throw new UnsupportedOperationException("LoadBalancerInterceptor invoked.");
86+
}
87+
88+
@Override
89+
public ServiceInstance choose(String serviceId) {
90+
throw new UnsupportedOperationException("LoadBalancerInterceptor invoked.");
91+
}
92+
93+
@Override
94+
public <T> ServiceInstance choose(String serviceId, Request<T> request) {
95+
throw new UnsupportedOperationException("LoadBalancerInterceptor invoked.");
96+
}
97+
};
98+
}
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}
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}

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

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/*
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* Copyright 2012-2023 the original author or authors.
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* Copyright 2012-2024 the original author or authors.
33
*
44
* Licensed under the Apache License, Version 2.0 (the "License");
55
* you may not use this file except in compliance with the License.
@@ -45,7 +45,10 @@ protected void assertLoadBalanced(RestTemplate restTemplate) {
4545
protected void assertLoadBalanced(RestClient.Builder restClientBuilder) {
4646
restClientBuilder.requestInterceptors(interceptors -> {
4747
assertThat(interceptors).hasSize(1);
48-
assertThat(interceptors.get(0)).isInstanceOf(LoadBalancerInterceptor.class);
48+
assertThat(interceptors.get(0)).isInstanceOf(DeferringLoadBalancerInterceptor.class);
49+
DeferringLoadBalancerInterceptor interceptor = (DeferringLoadBalancerInterceptor) interceptors.get(0);
50+
assertThat(interceptor.getLoadBalancerInterceptorProvider().getObject())
51+
.isInstanceOf(LoadBalancerInterceptor.class);
4952
});
5053
}
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