Added support for Feign + OkHttpClient + Sleuth

without this change we get exceptions related to not being able to extend a final class
with this change we're not wrapping any final types and we have a custom bean post processor for okhttp

fixes #513

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

@@ -596,11 +596,6 @@ include::../../../../spring-cloud-sleuth-core/src/test/java/org/springframework/
 Spring Cloud Sleuth integrates with http://projects.spring.io/spring-integration/[Spring Integration]. It creates spans for publish and
 subscribe events. To disable Spring Integration instrumentation, set `spring.sleuth.integration.enabled` to false.
 
-Spring Cloud Sleuth up till version 1.0.4 is sending invalid tracing headers when using messaging. Those headers are actually
-the same as the ones sent in HTTP (they contain a `-`) in its name. For the sake of
-backwards compatibility in 1.0.4 we've started sending both valid and invalid headers. Please upgrade to 1.0.4 because
-in Spring Cloud Sleuth 1.1 we will remove the support for the deprecated headers.
-
 You can provide the `spring.sleuth.integration.patterns` pattern to explicitly
 provide the names of channels that you want to include for tracing. By default all channels
 are included.

spring-cloud-sleuth-core/pom.xml

@@ -95,6 +95,11 @@
 			<artifactId>httpclient</artifactId>
 			<optional>true</optional>
 		</dependency>
+		<dependency>
+			<groupId>io.github.openfeign</groupId>
+			<artifactId>feign-okhttp</artifactId>
+			<optional>true</optional>
+		</dependency>
 		<dependency>
 			<groupId>org.aspectj</groupId>
 			<artifactId>aspectjrt</artifactId>

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/TraceWebAspect.java

@@ -34,12 +34,12 @@ import org.springframework.web.context.request.async.WebAsyncTask;
  * Aspect that adds tracing to
  * <p/>
  * <ul>
- * <li>{@link org.springframework.web.bind.annotation.RestController} annotated classes
+ * <li>{@code RestController} annotated classes
  * with public {@link Callable} methods</li>
  * <li>{@link org.springframework.stereotype.Controller} annotated classes with public
  * {@link Callable} methods</li>
  * <li>{@link org.springframework.stereotype.Controller} or
- * {@link org.springframework.web.bind.annotation.RestController} annotated classes with
+ * {@code RestController} annotated classes with
  * public {@link WebAsyncTask} methods</li>
  * </ul>
  * <p/>
@@ -57,7 +57,6 @@ import org.springframework.web.context.request.async.WebAsyncTask;
  * @author Spencer Gibb
  * @since 1.0.0
  *
- * @see org.springframework.web.bind.annotation.RestController
  * @see org.springframework.stereotype.Controller
  * @see org.springframework.web.client.RestOperations
  * @see org.springframework.cloud.sleuth.TraceCallable

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/client/feign/OkHttpFeignClientBeanPostProcessor.java

@@ -0,0 +1,62 @@
+/*
+ * Copyright 2013-2016 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
+ *
+ *      http://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.sleuth.instrument.web.client.feign;
+
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.BeanFactory;
+import org.springframework.beans.factory.config.BeanPostProcessor;
+
+import feign.okhttp.OkHttpClient;
+
+/**
+ * Post processor that wraps takes care of the OkHttp Feign Client instrumentation
+ *
+ * @author Marcin Grzejszczak
+ *
+ * @since 1.1.3
+ */
+final class OkHttpFeignClientBeanPostProcessor implements BeanPostProcessor {
+
+	private final BeanFactory beanFactory;
+	private TraceFeignObjectWrapper traceFeignObjectWrapper;
+
+	OkHttpFeignClientBeanPostProcessor(BeanFactory beanFactory) {
+		this.beanFactory = beanFactory;
+	}
+
+	@Override
+	public Object postProcessBeforeInitialization(Object bean, String beanName)
+			throws BeansException {
+		if (bean instanceof OkHttpClient) {
+			return getTraceFeignObjectWrapper().wrap(bean);
+		}
+		return bean;
+	}
+
+	@Override
+	public Object postProcessAfterInitialization(Object bean, String beanName)
+			throws BeansException {
+		return bean;
+	}
+
+	private TraceFeignObjectWrapper getTraceFeignObjectWrapper() {
+		if (this.traceFeignObjectWrapper == null) {
+			this.traceFeignObjectWrapper = this.beanFactory.getBean(TraceFeignObjectWrapper.class);
+		}
+		return this.traceFeignObjectWrapper;
+	}
+}

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/client/feign/TraceFeignAspect.java

@@ -39,7 +39,7 @@ class TraceFeignAspect {
 		this.beanFactory = beanFactory;
 	}
 
-	@Around("execution (* feign.Client.*(..))")
+	@Around("execution (* feign.Client.*(..)) && !within(is(FinalType))")
 	public Object feignClientWasCalled(final ProceedingJoinPoint pjp) throws Throwable {
 		Object[] args = pjp.getArgs();
 		Request request = (Request) args[0];

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/client/feign/TraceFeignClientAutoConfiguration.java

@@ -33,6 +33,7 @@ import org.springframework.context.annotation.Scope;
 
 import feign.Client;
 import feign.Feign;
+import feign.okhttp.OkHttpClient;
 
 /**
  * {@link org.springframework.boot.autoconfigure.EnableAutoConfiguration
@@ -75,6 +76,16 @@ public class TraceFeignClientAutoConfiguration {
 		}
 	}
 
+	@Configuration
+	@ConditionalOnClass(OkHttpClient.class)
+	protected static class OkHttpClientFeignBeanPostProcessorConfiguration {
+
+		@Bean
+		OkHttpFeignClientBeanPostProcessor okHttpFeignClientBeanPostProcessor(BeanFactory beanFactory) {
+			return new OkHttpFeignClientBeanPostProcessor(beanFactory);
+		}
+	}
+
 	@Bean
 	TraceFeignObjectWrapper traceFeignObjectWrapper(BeanFactory beanFactory) {
 		return new TraceFeignObjectWrapper(beanFactory);

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/web/client/feign/issues/issue393/Issue393Tests.java

@@ -41,6 +41,8 @@ import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestTemplate;
 
+import feign.okhttp.OkHttpClient;
+
 import static org.assertj.core.api.BDDAssertions.then;
 
 /**
@@ -89,6 +91,12 @@ class Application {
 		return new DemoController(myNameRemote);
 	}
 
+	// issue #513
+	@Bean
+	public OkHttpClient myOkHttpClient() {
+		return new OkHttpClient();
+	}
+
 	@Bean
 	public feign.Logger.Level feignLoggerLevel() {
 		return feign.Logger.Level.BASIC;