Fix gh 177 add sc loadbalancer support (#239)

* Add FeignBlockingLoadBalancerClient, configurations for default, apache
httpclient and okhttp setup. Add autoconfiguration. Init fix for gh-177.

* Fix SC loadbalancer dependencies.

* Fix generating Feign response when instance not found.

* Fix configuration.

* Add tests for FeignBlockingLoadBalancerClient and FeignLoadBalancerAutoConfiguration.

* Fix checkstyle and formatting.

* Refactor, add docs and javadocs.

* Fix author name.

* Fix docs after code review.

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

@@ -9,7 +9,13 @@ include::intro.adoc[]
 [[spring-cloud-feign]]
 == Declarative REST Client: Feign
 
-https://github.com/Netflix/feign[Feign] is a declarative web service client.  It makes writing web service clients easier.  To use Feign create an interface and annotate it.  It has pluggable annotation support including Feign annotations and JAX-RS annotations. Feign also supports pluggable encoders and decoders.  Spring Cloud adds support for Spring MVC annotations and for using the same `HttpMessageConverters` used by default in Spring Web.  Spring Cloud integrates Ribbon and Eureka to provide a load balanced http client when using Feign.
+https://github.com/OpenFeign/feign[Feign] is a declarative web service client.
+It makes writing web service clients easier.
+To use Feign create an interface and annotate it.
+It has pluggable annotation support including Feign annotations and JAX-RS annotations.
+Feign also supports pluggable encoders and decoders.
+Spring Cloud adds support for Spring MVC annotations and for using the same `HttpMessageConverters` used by default in Spring Web.
+Spring Cloud integrates Ribbon and Eureka, as well as Spring Cloud LoadBalancer to provide a load-balanced http client when using Feign.
 
 [[netflix-feign-starter]]
 === How to Include Feign
@@ -46,22 +52,24 @@ public interface StoreClient {
 }
 ----
 
-In the `@FeignClient` annotation the String value ("stores" above) is
-an arbitrary client name, which is used to create a Ribbon load
-balancer (see <<spring-cloud-ribbon,below for details of Ribbon
-support>>). You can also specify a URL using the `url` attribute
+In the `@FeignClient` annotation the String value ("stores" above) is an arbitrary client name, which is used to create either a https://github.com/Netflix/ribbon[Ribbon] load-balancer (see <<spring-cloud-ribbon,below for details of Ribbon support>>) or https://github.com/spring-cloud/spring-cloud-commons/blob/master/spring-cloud-commons/src/main/java/org/springframework/cloud/client/loadbalancer/reactive/ReactiveLoadBalancer.java[Spring Cloud LoadBalancer].
+You can also specify a URL using the `url` attribute
 (absolute value or just a hostname). The name of the bean in the
 application context is the fully qualified name of the interface.
 To specify your own alias value you can use the `qualifier` value
 of the `@FeignClient` annotation.
 
-The Ribbon client above will want to discover the physical addresses
+The load-balancer client above will want to discover the physical addresses
 for the "stores" service. If your application is a Eureka client then
 it will resolve the service in the Eureka service registry. If you
 don't want to use Eureka, you can simply configure a list of servers
 in your external configuration (see
 <<spring-cloud-ribbon-without-eureka,above for example>>).
 
+WARNING: In order to maintain backward compatibility, is used as the default load-balancer implementation.
+However, Spring Cloud Netflix Ribbon is now in maintenance mode, so we recommend using Spring Cloud LoadBalancer instead.
+To do this, set the value of `spring.cloud.loadbalancer.ribbon.enabled` to `false`.
+
 [[spring-cloud-feign-overriding-defaults]]
 === Overriding Feign Defaults
 
@@ -109,7 +117,10 @@ Spring Cloud Netflix provides the following beans by default for feign (`BeanTyp
 * `Logger` feignLogger: `Slf4jLogger`
 * `Contract` feignContract: `SpringMvcContract`
 * `Feign.Builder` feignBuilder: `HystrixFeign.Builder`
-* `Client` feignClient: if Ribbon is enabled it is a `LoadBalancerFeignClient`, otherwise the default feign client is used.
+* `Client` feignClient: if Ribbon is in the classpath and is enabled it is a `LoadBalancerFeignClient`, otherwise if Spring Cloud LoadBalancer is in the classpath, `FeignBlockingLoadBalancerClient` is used.
+If none of them is in the classpath, the default feign client is used.
+
+NOTE: `spring-cloud-starter-openfeign` contains both `spring-cloud-starter-netflix-ribbon` and `spring-cloud-starter-loadbalancer`.
 
 The OkHttpClient and ApacheHttpClient feign clients can be used by setting `feign.okhttp.enabled` or `feign.httpclient.enabled` to `true`, respectively, and having them on the classpath.
 You can customize the HTTP client used by providing a bean of either `org.apache.http.impl.client.CloseableHttpClient` when using Apache or `okhttp3.OkHttpClient` when using OK HTTP.

spring-cloud-openfeign-core/pom.xml

@@ -231,6 +231,11 @@
 			<version>0.10.0</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-loadbalancer</artifactId>
+			<optional>true</optional>
+		</dependency>
 	</dependencies>
 	<profiles>
 		<profile>

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/clientconfig/HttpClientFeignConfiguration.java

@@ -0,0 +1,123 @@
+/*
+ * Copyright 2013-2019 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.openfeign.clientconfig;
+
+import java.util.Timer;
+import java.util.TimerTask;
+
+import javax.annotation.PreDestroy;
+
+import org.apache.http.client.config.RequestConfig;
+import org.apache.http.config.RegistryBuilder;
+import org.apache.http.conn.HttpClientConnectionManager;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.apache.http.impl.client.HttpClientBuilder;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.cloud.commons.httpclient.ApacheHttpClientConnectionManagerFactory;
+import org.springframework.cloud.commons.httpclient.ApacheHttpClientFactory;
+import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Default configuration for {@link CloseableHttpClient}.
+ *
+ * @author Ryan Baxter
+ * @author Marcin Grzejszczak
+ * @author Spencer Gibb
+ * @author Olga Maciaszek-Sharma
+ */
+@Configuration
+@ConditionalOnMissingBean(CloseableHttpClient.class)
+public class HttpClientFeignConfiguration {
+
+	private final Timer connectionManagerTimer = new Timer(
+			"FeignApacheHttpClientConfiguration.connectionManagerTimer", true);
+
+	private CloseableHttpClient httpClient;
+
+	@Autowired(required = false)
+	private RegistryBuilder registryBuilder;
+
+	@Bean
+	@ConditionalOnMissingBean(HttpClientConnectionManager.class)
+	public HttpClientConnectionManager connectionManager(
+			ApacheHttpClientConnectionManagerFactory connectionManagerFactory,
+			FeignHttpClientProperties httpClientProperties) {
+		final HttpClientConnectionManager connectionManager = connectionManagerFactory
+				.newConnectionManager(httpClientProperties.isDisableSslValidation(),
+						httpClientProperties.getMaxConnections(),
+						httpClientProperties.getMaxConnectionsPerRoute(),
+						httpClientProperties.getTimeToLive(),
+						httpClientProperties.getTimeToLiveUnit(), this.registryBuilder);
+		this.connectionManagerTimer.schedule(new TimerTask() {
+			@Override
+			public void run() {
+				connectionManager.closeExpiredConnections();
+			}
+		}, 30000, httpClientProperties.getConnectionTimerRepeat());
+		return connectionManager;
+	}
+
+	@Bean
+	@ConditionalOnProperty(value = "feign.compression.response.enabled",
+			havingValue = "true")
+	public CloseableHttpClient customHttpClient(
+			HttpClientConnectionManager httpClientConnectionManager,
+			FeignHttpClientProperties httpClientProperties) {
+		HttpClientBuilder builder = HttpClientBuilder.create().disableCookieManagement()
+				.useSystemProperties();
+		this.httpClient = createClient(builder, httpClientConnectionManager,
+				httpClientProperties);
+		return this.httpClient;
+	}
+
+	@Bean
+	@ConditionalOnProperty(value = "feign.compression.response.enabled",
+			havingValue = "false", matchIfMissing = true)
+	public CloseableHttpClient httpClient(ApacheHttpClientFactory httpClientFactory,
+			HttpClientConnectionManager httpClientConnectionManager,
+			FeignHttpClientProperties httpClientProperties) {
+		this.httpClient = createClient(httpClientFactory.createBuilder(),
+				httpClientConnectionManager, httpClientProperties);
+		return this.httpClient;
+	}
+
+	private CloseableHttpClient createClient(HttpClientBuilder builder,
+			HttpClientConnectionManager httpClientConnectionManager,
+			FeignHttpClientProperties httpClientProperties) {
+		RequestConfig defaultRequestConfig = RequestConfig.custom()
+				.setConnectTimeout(httpClientProperties.getConnectionTimeout())
+				.setRedirectsEnabled(httpClientProperties.isFollowRedirects()).build();
+		CloseableHttpClient httpClient = builder
+				.setDefaultRequestConfig(defaultRequestConfig)
+				.setConnectionManager(httpClientConnectionManager).build();
+		return httpClient;
+	}
+
+	@PreDestroy
+	public void destroy() throws Exception {
+		this.connectionManagerTimer.cancel();
+		if (this.httpClient != null) {
+			this.httpClient.close();
+		}
+	}
+
+}

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/clientconfig/OkHttpFeignConfiguration.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2013-2019 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.openfeign.clientconfig;
+
+import java.util.concurrent.TimeUnit;
+
+import javax.annotation.PreDestroy;
+
+import okhttp3.ConnectionPool;
+import okhttp3.OkHttpClient;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.cloud.commons.httpclient.OkHttpClientConnectionPoolFactory;
+import org.springframework.cloud.commons.httpclient.OkHttpClientFactory;
+import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Defualt configuration for {@link OkHttpClient}.
+ *
+ * @author Ryan Baxter
+ * @author Marcin Grzejszczak
+ * @author Spencer Gibb
+ * @author Olga Maciaszek-Sharma
+ */
+@Configuration
+@ConditionalOnMissingBean(okhttp3.OkHttpClient.class)
+public class OkHttpFeignConfiguration {
+
+	private okhttp3.OkHttpClient okHttpClient;
+
+	@Bean
+	@ConditionalOnMissingBean(ConnectionPool.class)
+	public ConnectionPool httpClientConnectionPool(
+			FeignHttpClientProperties httpClientProperties,
+			OkHttpClientConnectionPoolFactory connectionPoolFactory) {
+		Integer maxTotalConnections = httpClientProperties.getMaxConnections();
+		Long timeToLive = httpClientProperties.getTimeToLive();
+		TimeUnit ttlUnit = httpClientProperties.getTimeToLiveUnit();
+		return connectionPoolFactory.create(maxTotalConnections, timeToLive, ttlUnit);
+	}
+
+	@Bean
+	public okhttp3.OkHttpClient client(OkHttpClientFactory httpClientFactory,
+			ConnectionPool connectionPool,
+			FeignHttpClientProperties httpClientProperties) {
+		Boolean followRedirects = httpClientProperties.isFollowRedirects();
+		Integer connectTimeout = httpClientProperties.getConnectionTimeout();
+		this.okHttpClient = httpClientFactory
+				.createBuilder(httpClientProperties.isDisableSslValidation())
+				.connectTimeout(connectTimeout, TimeUnit.MILLISECONDS)
+				.followRedirects(followRedirects).connectionPool(connectionPool).build();
+		return this.okHttpClient;
+	}
+
+	@PreDestroy
+	public void destroy() {
+		if (this.okHttpClient != null) {
+			this.okHttpClient.dispatcher().executorService().shutdown();
+			this.okHttpClient.connectionPool().evictAll();
+		}
+	}
+
+}

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

@@ -0,0 +1,43 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import feign.Client;
+
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Configuration instantiating a {@link BlockingLoadBalancerClient}-based {@link Client}
+ * object that uses {@link Client.Default} under the hood.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+@Configuration
+class DefaultFeignLoadBalancerConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	public Client feignClient(BlockingLoadBalancerClient loadBalancerClient) {
+		return new FeignBlockingLoadBalancerClient(new Client.Default(null, null),
+				loadBalancerClient);
+	}
+
+}

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

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import java.io.IOException;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+
+import feign.Client;
+import feign.Request;
+import feign.Response;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.http.HttpStatus;
+import org.springframework.util.Assert;
+
+/**
+ * A {@link Client} implementation that uses {@link BlockingLoadBalancerClient} to select
+ * a {@link ServiceInstance} to use while resolving the request host.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+class FeignBlockingLoadBalancerClient implements Client {
+
+	private static final Log LOG = LogFactory
+			.getLog(FeignBlockingLoadBalancerClient.class);
+
+	private final Client delegate;
+
+	private final BlockingLoadBalancerClient loadBalancerClient;
+
+	FeignBlockingLoadBalancerClient(Client delegate,
+			BlockingLoadBalancerClient loadBalancerClient) {
+		this.delegate = delegate;
+		this.loadBalancerClient = loadBalancerClient;
+	}
+
+	@Override
+	public Response execute(Request request, Request.Options options) throws IOException {
+		final URI originalUri = URI.create(request.url());
+		String serviceId = originalUri.getHost();
+		Assert.state(serviceId != null,
+				"Request URI does not contain a valid hostname: " + originalUri);
+		ServiceInstance instance = loadBalancerClient.choose(serviceId);
+		if (instance == null) {
+			String message = "Load balancer does not contain an instance for the service "
+					+ serviceId;
+			if (LOG.isWarnEnabled()) {
+				LOG.warn(message);
+			}
+			return Response.builder().request(request)
+					.status(HttpStatus.SERVICE_UNAVAILABLE.value())
+					.body(message, StandardCharsets.UTF_8).build();
+		}
+		String reconstructedUrl = loadBalancerClient.reconstructURI(instance, originalUri)
+				.toString();
+		Request newRequest = Request.create(request.httpMethod(), reconstructedUrl,
+				request.headers(), request.requestBody());
+
+		return delegate.execute(newRequest, options);
+	}
+
+	// Visible for tests
+	Client getDelegate() {
+		return delegate;
+	}
+
+}

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

@@ -0,0 +1,57 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import feign.Client;
+import feign.Feign;
+
+import org.springframework.boot.autoconfigure.AutoConfigureAfter;
+import org.springframework.boot.autoconfigure.AutoConfigureBefore;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.cloud.openfeign.FeignAutoConfiguration;
+import org.springframework.cloud.openfeign.ribbon.FeignRibbonClientAutoConfiguration;
+import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+/**
+ * An autoconfiguration that instantiates {@link BlockingLoadBalancerClient}-based
+ * implementations of {@link Client}. In order to use this load-balancing mechanism, the
+ * Ribbon-based implementation has to be disabled by setting
+ * <code>spring.cloud.loadbalancer.ribbon.enabled</code> to <code>true</code>.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+@ConditionalOnClass(Feign.class)
+@ConditionalOnBean(BlockingLoadBalancerClient.class)
+@AutoConfigureBefore(FeignAutoConfiguration.class)
+@AutoConfigureAfter(FeignRibbonClientAutoConfiguration.class)
+@EnableConfigurationProperties(FeignHttpClientProperties.class)
+@Configuration
+// Order is important here, last should be the default, first should be optional
+// see
+// https://github.com/spring-cloud/spring-cloud-netflix/issues/2086#issuecomment-316281653
+@Import({ HttpClientFeignLoadBalancerConfiguration.class,
+		OkHttpFeignLoadBalancerConfiguration.class,
+		DefaultFeignLoadBalancerConfiguration.class })
+class FeignLoadBalancerAutoConfiguration {
+
+}

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

@@ -0,0 +1,55 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import feign.Client;
+import feign.httpclient.ApacheHttpClient;
+import org.apache.http.client.HttpClient;
+
+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.condition.ConditionalOnProperty;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.cloud.openfeign.clientconfig.HttpClientFeignConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+/**
+ * Configuration instantiating a {@link BlockingLoadBalancerClient}-based {@link Client}
+ * object that uses {@link ApacheHttpClient} under the hood.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+@Configuration
+@ConditionalOnClass(ApacheHttpClient.class)
+@ConditionalOnBean(BlockingLoadBalancerClient.class)
+@ConditionalOnProperty(value = "feign.httpclient.enabled", matchIfMissing = true)
+@Import(HttpClientFeignConfiguration.class)
+class HttpClientFeignLoadBalancerConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	public Client feignClient(BlockingLoadBalancerClient loadBalancerClient,
+			HttpClient httpClient) {
+		ApacheHttpClient delegate = new ApacheHttpClient(httpClient);
+		return new FeignBlockingLoadBalancerClient(delegate, loadBalancerClient);
+	}
+
+}

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

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import feign.Client;
+import feign.okhttp.OkHttpClient;
+
+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.condition.ConditionalOnProperty;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.cloud.openfeign.clientconfig.OkHttpFeignConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+
+/**
+ * Configuration instantiating a {@link BlockingLoadBalancerClient}-based {@link Client}
+ * object that uses {@link OkHttpClient} under the hood.
+ *
+ * @author Olga Maciaszek-Sharma
+ * @since 2.2.0
+ */
+@Configuration
+@ConditionalOnClass(OkHttpClient.class)
+@ConditionalOnProperty("feign.okhttp.enabled")
+@ConditionalOnBean(BlockingLoadBalancerClient.class)
+@Import(OkHttpFeignConfiguration.class)
+class OkHttpFeignLoadBalancerConfiguration {
+
+	@Bean
+	@ConditionalOnMissingBean
+	public Client feignClient(okhttp3.OkHttpClient okHttpClient,
+			BlockingLoadBalancerClient loadBalancerClient) {
+		OkHttpClient delegate = new OkHttpClient(okHttpClient);
+		return new FeignBlockingLoadBalancerClient(delegate, loadBalancerClient);
+	}
+
+}

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/ribbon/FeignRibbonClientAutoConfiguration.java

@@ -24,6 +24,7 @@ import org.springframework.boot.autoconfigure.AutoConfigureBefore;
 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.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryFactory;
 import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
@@ -39,8 +40,11 @@ import org.springframework.context.annotation.Primary;
  * load balancer.
  *
  * @author Dave Syer
+ * @author Olga Maciaszek-Sharma
  */
 @ConditionalOnClass({ ILoadBalancer.class, Feign.class })
+@ConditionalOnProperty(value = "spring.cloud.loadbalancer.ribbon.enabled",
+		matchIfMissing = true)
 @Configuration
 @AutoConfigureBefore(FeignAutoConfiguration.class)
 @EnableConfigurationProperties({ FeignHttpClientProperties.class })

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/ribbon/HttpClientFeignLoadBalancedConfiguration.java

@@ -16,37 +16,27 @@
 
 package org.springframework.cloud.openfeign.ribbon;
 
-import java.util.Timer;
-import java.util.TimerTask;
-
-import javax.annotation.PreDestroy;
-
 import feign.Client;
 import feign.httpclient.ApacheHttpClient;
 import org.apache.http.client.HttpClient;
-import org.apache.http.client.config.RequestConfig;
-import org.apache.http.config.RegistryBuilder;
-import org.apache.http.conn.HttpClientConnectionManager;
-import org.apache.http.impl.client.CloseableHttpClient;
-import org.apache.http.impl.client.HttpClientBuilder;
 
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.cloud.commons.httpclient.ApacheHttpClientConnectionManagerFactory;
-import org.springframework.cloud.commons.httpclient.ApacheHttpClientFactory;
 import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
-import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
+import org.springframework.cloud.openfeign.clientconfig.HttpClientFeignConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 
 /**
  * @author Spencer Gibb
+ * @author Olga Maciaszek-Sharma
  */
 @Configuration
 @ConditionalOnClass(ApacheHttpClient.class)
 @ConditionalOnProperty(value = "feign.httpclient.enabled", matchIfMissing = true)
+@Import(HttpClientFeignConfiguration.class)
 class HttpClientFeignLoadBalancedConfiguration {
 
 	@Bean
@@ -57,84 +47,4 @@ class HttpClientFeignLoadBalancedConfiguration {
 		return new LoadBalancerFeignClient(delegate, cachingFactory, clientFactory);
 	}
 
-	@Configuration
-	@ConditionalOnMissingBean(CloseableHttpClient.class)
-	protected static class HttpClientFeignConfiguration {
-
-		private final Timer connectionManagerTimer = new Timer(
-				"FeignApacheHttpClientConfiguration.connectionManagerTimer", true);
-
-		private CloseableHttpClient httpClient;
-
-		@Autowired(required = false)
-		private RegistryBuilder registryBuilder;
-
-		@Bean
-		@ConditionalOnMissingBean(HttpClientConnectionManager.class)
-		public HttpClientConnectionManager connectionManager(
-				ApacheHttpClientConnectionManagerFactory connectionManagerFactory,
-				FeignHttpClientProperties httpClientProperties) {
-			final HttpClientConnectionManager connectionManager = connectionManagerFactory
-					.newConnectionManager(httpClientProperties.isDisableSslValidation(),
-							httpClientProperties.getMaxConnections(),
-							httpClientProperties.getMaxConnectionsPerRoute(),
-							httpClientProperties.getTimeToLive(),
-							httpClientProperties.getTimeToLiveUnit(),
-							this.registryBuilder);
-			this.connectionManagerTimer.schedule(new TimerTask() {
-				@Override
-				public void run() {
-					connectionManager.closeExpiredConnections();
-				}
-			}, 30000, httpClientProperties.getConnectionTimerRepeat());
-			return connectionManager;
-		}
-
-		@Bean
-		@ConditionalOnProperty(value = "feign.compression.response.enabled",
-				havingValue = "true")
-		public CloseableHttpClient customHttpClient(
-				HttpClientConnectionManager httpClientConnectionManager,
-				FeignHttpClientProperties httpClientProperties) {
-			HttpClientBuilder builder = HttpClientBuilder.create()
-					.disableCookieManagement().useSystemProperties();
-			this.httpClient = createClient(builder, httpClientConnectionManager,
-					httpClientProperties);
-			return this.httpClient;
-		}
-
-		@Bean
-		@ConditionalOnProperty(value = "feign.compression.response.enabled",
-				havingValue = "false", matchIfMissing = true)
-		public CloseableHttpClient httpClient(ApacheHttpClientFactory httpClientFactory,
-				HttpClientConnectionManager httpClientConnectionManager,
-				FeignHttpClientProperties httpClientProperties) {
-			this.httpClient = createClient(httpClientFactory.createBuilder(),
-					httpClientConnectionManager, httpClientProperties);
-			return this.httpClient;
-		}
-
-		private CloseableHttpClient createClient(HttpClientBuilder builder,
-				HttpClientConnectionManager httpClientConnectionManager,
-				FeignHttpClientProperties httpClientProperties) {
-			RequestConfig defaultRequestConfig = RequestConfig.custom()
-					.setConnectTimeout(httpClientProperties.getConnectionTimeout())
-					.setRedirectsEnabled(httpClientProperties.isFollowRedirects())
-					.build();
-			CloseableHttpClient httpClient = builder
-					.setDefaultRequestConfig(defaultRequestConfig)
-					.setConnectionManager(httpClientConnectionManager).build();
-			return httpClient;
-		}
-
-		@PreDestroy
-		public void destroy() throws Exception {
-			this.connectionManagerTimer.cancel();
-			if (this.httpClient != null) {
-				this.httpClient.close();
-			}
-		}
-
-	}
-
 }

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/ribbon/OkHttpFeignLoadBalancedConfiguration.java

@@ -16,30 +16,26 @@
 
 package org.springframework.cloud.openfeign.ribbon;
 
-import java.util.concurrent.TimeUnit;
-
-import javax.annotation.PreDestroy;
-
 import feign.Client;
 import feign.okhttp.OkHttpClient;
-import okhttp3.ConnectionPool;
 
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.cloud.commons.httpclient.OkHttpClientConnectionPoolFactory;
-import org.springframework.cloud.commons.httpclient.OkHttpClientFactory;
 import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
-import org.springframework.cloud.openfeign.support.FeignHttpClientProperties;
+import org.springframework.cloud.openfeign.clientconfig.OkHttpFeignConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
 
 /**
  * @author Spencer Gibb
+ * @author Olga Maciaszek-Sharma
  */
 @Configuration
 @ConditionalOnClass(OkHttpClient.class)
 @ConditionalOnProperty("feign.okhttp.enabled")
+@Import(OkHttpFeignConfiguration.class)
 class OkHttpFeignLoadBalancedConfiguration {
 
 	@Bean
@@ -50,45 +46,4 @@ class OkHttpFeignLoadBalancedConfiguration {
 		return new LoadBalancerFeignClient(delegate, cachingFactory, clientFactory);
 	}
 
-	@Configuration
-	@ConditionalOnMissingBean(okhttp3.OkHttpClient.class)
-	protected static class OkHttpFeignConfiguration {
-
-		private okhttp3.OkHttpClient okHttpClient;
-
-		@Bean
-		@ConditionalOnMissingBean(ConnectionPool.class)
-		public ConnectionPool httpClientConnectionPool(
-				FeignHttpClientProperties httpClientProperties,
-				OkHttpClientConnectionPoolFactory connectionPoolFactory) {
-			Integer maxTotalConnections = httpClientProperties.getMaxConnections();
-			Long timeToLive = httpClientProperties.getTimeToLive();
-			TimeUnit ttlUnit = httpClientProperties.getTimeToLiveUnit();
-			return connectionPoolFactory.create(maxTotalConnections, timeToLive, ttlUnit);
-		}
-
-		@Bean
-		public okhttp3.OkHttpClient client(OkHttpClientFactory httpClientFactory,
-				ConnectionPool connectionPool,
-				FeignHttpClientProperties httpClientProperties) {
-			Boolean followRedirects = httpClientProperties.isFollowRedirects();
-			Integer connectTimeout = httpClientProperties.getConnectionTimeout();
-			this.okHttpClient = httpClientFactory
-					.createBuilder(httpClientProperties.isDisableSslValidation())
-					.connectTimeout(connectTimeout, TimeUnit.MILLISECONDS)
-					.followRedirects(followRedirects).connectionPool(connectionPool)
-					.build();
-			return this.okHttpClient;
-		}
-
-		@PreDestroy
-		public void destroy() {
-			if (this.okHttpClient != null) {
-				this.okHttpClient.dispatcher().executorService().shutdown();
-				this.okHttpClient.connectionPool().evictAll();
-			}
-		}
-
-	}
-
 }

spring-cloud-openfeign-core/src/main/resources/META-INF/spring.factories

@@ -3,4 +3,5 @@ org.springframework.cloud.openfeign.ribbon.FeignRibbonClientAutoConfiguration,\
 org.springframework.cloud.openfeign.hateoas.FeignHalAutoConfiguration,\
 org.springframework.cloud.openfeign.FeignAutoConfiguration,\
 org.springframework.cloud.openfeign.encoding.FeignAcceptGzipEncodingAutoConfiguration,\
-org.springframework.cloud.openfeign.encoding.FeignContentGzipEncodingAutoConfiguration
+org.springframework.cloud.openfeign.encoding.FeignContentGzipEncodingAutoConfiguration,\
+org.springframework.cloud.openfeign.loadbalancer.FeignLoadBalancerAutoConfiguration

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

@@ -0,0 +1,145 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import java.io.IOException;
+import java.net.URI;
+import java.nio.charset.StandardCharsets;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import feign.Client;
+import feign.Request;
+import feign.Response;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+import org.mockito.ArgumentCaptor;
+import org.mockito.junit.jupiter.MockitoExtension;
+
+import org.springframework.cloud.client.DefaultServiceInstance;
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
+import static org.mockito.ArgumentMatchers.eq;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+/**
+ * Tests for {@link FeignBlockingLoadBalancerClient}. Note: the underlying
+ * {@link BlockingLoadBalancerClient} is already extensively tested in the Spring Cloud
+ * Commons project, so here we are only testing the interactions between
+ * {@link FeignBlockingLoadBalancerClient} and its delegates.
+ *
+ * @see <a href=
+ * "https://github.com/spring-cloud/spring-cloud-commons/blob/master/spring-cloud-loadbalancer/src/test/java/org/springframework/cloud/loadbalancer/blocking/client/BlockingLoadBalancerClientTests.java">BlockingLoadBalancerClientTests</a>
+ * @author Olga Maciaszek-Sharma
+ */
+@ExtendWith(MockitoExtension.class)
+class FeignBlockingLoadBalancerClientTests {
+
+	private Client delegate = mock(Client.class);
+
+	private BlockingLoadBalancerClient loadBalancerClient = mock(
+			BlockingLoadBalancerClient.class);
+
+	private FeignBlockingLoadBalancerClient feignBlockingLoadBalancerClient = new FeignBlockingLoadBalancerClient(
+			delegate, loadBalancerClient);
+
+	@Test
+	void shouldExtractServiceIdFromRequestUrl() throws IOException {
+		Request request = testRequest();
+
+		feignBlockingLoadBalancerClient.execute(request, new Request.Options());
+
+		verify(loadBalancerClient).choose("test");
+	}
+
+	@Test
+	void shouldThrowExceptionIfNoServiceId() {
+		Request request = testRequest("");
+
+		assertThatIllegalStateException()
+				.isThrownBy(() -> feignBlockingLoadBalancerClient.execute(request,
+						new Request.Options()))
+				.withMessage(
+						"Request URI does not contain a valid hostname: http:///path");
+	}
+
+	@Test
+	void shouldRespondWithServiceUnavailableIfInstanceNotFound() throws IOException {
+		Request request = testRequest();
+
+		Response response = feignBlockingLoadBalancerClient.execute(request,
+				new Request.Options());
+
+		assertThat(response.status()).isEqualTo(HttpStatus.SERVICE_UNAVAILABLE.value());
+		assertThat(response.body().toString()).isEqualTo(
+				"Load balancer does not contain an instance for the service test");
+	}
+
+	@Test
+	void shouldPassCorrectRequestToDelegate() throws IOException {
+		Request request = testRequest();
+		Request.Options options = new Request.Options();
+		String url = "http://127.0.0.1/path";
+		ServiceInstance serviceInstance = new DefaultServiceInstance("test-1", "test",
+				"test-host", 8888, false);
+		when(loadBalancerClient.choose("test")).thenReturn(serviceInstance);
+		when(loadBalancerClient.reconstructURI(serviceInstance,
+				URI.create("http://test/path"))).thenReturn(URI.create(url));
+
+		feignBlockingLoadBalancerClient.execute(request, options);
+
+		ArgumentCaptor<Request> captor = ArgumentCaptor.forClass(Request.class);
+		verify(delegate, times(1)).execute(captor.capture(), eq(options));
+		Request actualRequest = captor.getValue();
+		assertThat(actualRequest.httpMethod()).isEqualTo(Request.HttpMethod.GET);
+		assertThat(actualRequest.url()).isEqualTo(url);
+		assertThat(actualRequest.headers()).hasSize(1);
+		assertThat(actualRequest.headers()).containsEntry(HttpHeaders.CONTENT_TYPE,
+				Collections.singletonList(MediaType.APPLICATION_JSON_VALUE));
+		assertThat(actualRequest.requestBody().asString()).isEqualTo("hello");
+	}
+
+	private Request testRequest() {
+		return testRequest("test");
+	}
+
+	private Request testRequest(String host) {
+		return Request.create(Request.HttpMethod.GET, "http://" + host + "/path",
+				testHeaders(),
+				Request.Body.encoded("hello".getBytes(), StandardCharsets.UTF_8));
+	}
+
+	private Map<String, Collection<String>> testHeaders() {
+		Map<String, Collection<String>> feignHeaders = new HashMap<>();
+		feignHeaders.put(HttpHeaders.CONTENT_TYPE,
+				Collections.singletonList(MediaType.APPLICATION_JSON_VALUE));
+		return feignHeaders;
+
+	}
+
+}

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

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2013-2019 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.openfeign.loadbalancer;
+
+import java.util.Map;
+
+import feign.Client;
+import feign.httpclient.ApacheHttpClient;
+import feign.okhttp.OkHttpClient;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.boot.WebApplicationType;
+import org.springframework.boot.builder.SpringApplicationBuilder;
+import org.springframework.cloud.commons.httpclient.HttpClientConfiguration;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.cloud.loadbalancer.config.BlockingLoadBalancerClientAutoConfiguration;
+import org.springframework.cloud.loadbalancer.config.LoadBalancerAutoConfiguration;
+import org.springframework.cloud.netflix.ribbon.RibbonAutoConfiguration;
+import org.springframework.cloud.openfeign.ribbon.FeignRibbonClientAutoConfiguration;
+import org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient;
+import org.springframework.context.ConfigurableApplicationContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Olga Maciaszek-Sharma
+ */
+class FeignLoadBalancerAutoConfigurationTests {
+
+	@Test
+	void shouldInstantiateDefaultFeignBlockingLoadBalancerClientWhenHttpClientDisabled() {
+		ConfigurableApplicationContext context = initContext(
+				"spring.cloud.loadbalancer.ribbon.enabled=false",
+				"feign.httpclient.enabled=false");
+		assertThatOneBeanPresent(context, BlockingLoadBalancerClient.class);
+		assertLoadBalanced(context, Client.Default.class);
+		assertThatBeanNotPresent(context, LoadBalancerFeignClient.class);
+	}
+
+	@Test
+	void shouldInstantiateHttpFeignClientWhenEnabled() {
+		ConfigurableApplicationContext context = initContext(
+				"spring.cloud.loadbalancer.ribbon.enabled=false");
+		assertThatOneBeanPresent(context, BlockingLoadBalancerClient.class);
+		assertLoadBalanced(context, ApacheHttpClient.class);
+		assertThatBeanNotPresent(context, LoadBalancerFeignClient.class);
+	}
+
+	@Test
+	void shouldInstantiateOkHttpFeignClientWhenEnabled() {
+		ConfigurableApplicationContext context = initContext(
+				"spring.cloud.loadbalancer.ribbon.enabled=false",
+				"feign.httpclient.enabled=false", "feign.okhttp.enabled=true");
+		assertThatOneBeanPresent(context, BlockingLoadBalancerClient.class);
+		assertLoadBalanced(context, OkHttpClient.class);
+		assertThatBeanNotPresent(context, LoadBalancerFeignClient.class);
+	}
+
+	@Test
+	void shouldNotProcessLoadBalancerConfigurationWhenRibbonEnabled() {
+		ConfigurableApplicationContext context = initContext(
+				"spring.cloud.loadbalancer.ribbon.enabled=true");
+		assertThatOneBeanPresent(context, LoadBalancerFeignClient.class);
+		assertThatBeanNotPresent(context, BlockingLoadBalancerClient.class);
+		assertThatBeanNotPresent(context, FeignBlockingLoadBalancerClient.class);
+	}
+
+	private ConfigurableApplicationContext initContext(String... properties) {
+		return new SpringApplicationBuilder().web(WebApplicationType.NONE)
+				.properties(properties)
+				.sources(HttpClientConfiguration.class, RibbonAutoConfiguration.class,
+						LoadBalancerAutoConfiguration.class,
+						BlockingLoadBalancerClientAutoConfiguration.class,
+						FeignRibbonClientAutoConfiguration.class,
+						FeignLoadBalancerAutoConfiguration.class)
+				.run();
+	}
+
+	private void assertThatOneBeanPresent(ConfigurableApplicationContext context,
+			Class<?> beanClass) {
+		Map<String, ?> beans = context.getBeansOfType(beanClass);
+		assertThat(beans).hasSize(1);
+	}
+
+	private void assertLoadBalanced(ConfigurableApplicationContext context,
+			Class delegateClass) {
+		Map<String, FeignBlockingLoadBalancerClient> beans = context
+				.getBeansOfType(FeignBlockingLoadBalancerClient.class);
+		assertThat(beans).hasSize(1);
+		assertThat(beans.get("feignClient").getDelegate()).isInstanceOf(delegateClass);
+	}
+
+	private void assertThatBeanNotPresent(ConfigurableApplicationContext context,
+			Class<?> beanClass) {
+		Map<String, ?> beans = context.getBeansOfType(beanClass);
+		assertThat(beans).isEmpty();
+	}
+
+}

spring-cloud-starter-openfeign/pom.xml

@@ -62,5 +62,10 @@
 			<artifactId>spring-cloud-starter-netflix-archaius</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.cloud</groupId>
+			<artifactId>spring-cloud-starter-loadbalancer</artifactId>
+			<optional>true</optional>
+		</dependency>
 	</dependencies>
 </project>