Use delegate if absolute url provided. (#264)

Fixes gh-259
Fixes gh-257

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

@@ -37,6 +37,7 @@ import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.FactoryBean;
 import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
+import org.springframework.cloud.openfeign.loadbalancer.FeignBlockingLoadBalancerClient;
 import org.springframework.cloud.openfeign.ribbon.LoadBalancerFeignClient;
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
@@ -282,6 +283,11 @@ class FeignClientFactoryBean
 				// but ribbon is on the classpath, so unwrap
 				client = ((LoadBalancerFeignClient) client).getDelegate();
 			}
+			if (client instanceof FeignBlockingLoadBalancerClient) {
+				// not load balancing because we have a url,
+				// but Spring Cloud LoadBalancer is on the classpath, so unwrap
+				client = ((FeignBlockingLoadBalancerClient) client).getDelegate();
+			}
 			builder.client(client);
 		}
 		Targeter targeter = get(context, Targeter.class);

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

@@ -38,7 +38,7 @@ import org.springframework.util.Assert;
  * @author Olga Maciaszek-Sharma
  * @since 2.2.0
  */
-class FeignBlockingLoadBalancerClient implements Client {
+public class FeignBlockingLoadBalancerClient implements Client {
 
 	private static final Log LOG = LogFactory
 			.getLog(FeignBlockingLoadBalancerClient.class);
@@ -78,8 +78,7 @@ class FeignBlockingLoadBalancerClient implements Client {
 		return delegate.execute(newRequest, options);
 	}
 
-	// Visible for tests
-	Client getDelegate() {
+	public Client getDelegate() {
 		return delegate;
 	}
 

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

@@ -52,6 +52,6 @@ import org.springframework.context.annotation.Import;
 @Import({ HttpClientFeignLoadBalancerConfiguration.class,
 		OkHttpFeignLoadBalancerConfiguration.class,
 		DefaultFeignLoadBalancerConfiguration.class })
-class FeignLoadBalancerAutoConfiguration {
+public class FeignLoadBalancerAutoConfiguration {
 
 }

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

@@ -16,14 +16,30 @@
 
 package org.springframework.cloud.openfeign;
 
+import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.Map;
 
+import feign.Client;
+import feign.InvocationHandlerFactory;
 import org.junit.Test;
 
+import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.springframework.cloud.loadbalancer.blocking.client.BlockingLoadBalancerClient;
+import org.springframework.cloud.loadbalancer.config.LoadBalancerAutoConfiguration;
+import org.springframework.cloud.loadbalancer.support.LoadBalancerClientFactory;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.test.util.ReflectionTestUtils;
+import org.springframework.web.bind.annotation.RequestMapping;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.springframework.web.bind.annotation.RequestMethod.GET;
 
 /**
  * @author Spencer Gibb
@@ -49,10 +65,74 @@ public class FeignClientFactoryTests {
 		assertThat(foobar).as("bar was not null").isNull();
 	}
 
+	@Test
+	public void shouldRedirectToDelegateWhenUrlSet() {
+		new ApplicationContextRunner().withUserConfiguration(TestConfig.class)
+				.run(this::defaultClientUsed);
+	}
+
+	@SuppressWarnings({ "unchecked", "ConstantConditions" })
+	private void defaultClientUsed(AssertableApplicationContext context) {
+		Proxy target = context.getBean(FeignClientFactoryBean.class).getTarget();
+		Object invocationHandler = ReflectionTestUtils.getField(target, "h");
+		Map<Method, InvocationHandlerFactory.MethodHandler> dispatch = (Map<Method, InvocationHandlerFactory.MethodHandler>) ReflectionTestUtils
+				.getField(invocationHandler, "dispatch");
+		Method key = new ArrayList<>(dispatch.keySet()).get(0);
+		Object client = ReflectionTestUtils.getField(dispatch.get(key), "client");
+		assertThat(client).isInstanceOf(Client.Default.class);
+	}
+
 	private FeignClientSpecification getSpec(String name, Class<?> configClass) {
 		return new FeignClientSpecification(name, new Class[] { configClass });
 	}
 
+	interface TestType {
+
+		@RequestMapping(value = "/", method = GET)
+		String hello();
+
+	}
+
+	@Configuration
+	static class TestConfig {
+
+		@Bean
+		BlockingLoadBalancerClient loadBalancerClient() {
+			return new BlockingLoadBalancerClient(new LoadBalancerClientFactory());
+		}
+
+		@Bean
+		FeignContext feignContext() {
+			FeignContext feignContext = new FeignContext();
+			feignContext.setConfigurations(
+					Collections.singletonList(new FeignClientSpecification("test",
+							new Class[] { LoadBalancerAutoConfiguration.class })));
+			return feignContext;
+		}
+
+		@Bean
+		FeignClientProperties feignClientProperties() {
+			return new FeignClientProperties();
+		}
+
+		@Bean
+		Targeter targeter() {
+			return new DefaultTargeter();
+		}
+
+		@Bean
+		FeignClientFactoryBean feignClientFactoryBean() {
+			FeignClientFactoryBean feignClientFactoryBean = new FeignClientFactoryBean();
+			feignClientFactoryBean.setContextId("test");
+			feignClientFactoryBean.setName("test");
+			feignClientFactoryBean.setType(TestType.class);
+			feignClientFactoryBean.setPath("");
+			feignClientFactoryBean.setUrl("http://some.absolute.url");
+			return feignClientFactoryBean;
+		}
+
+	}
+
 	static class FooConfig {
 
 		@Bean