Refactor @FeignClient to use name= or url= but not both

Replaces the boolean flag (loadbalance) for switching between service
resolution (by name) or straight URL bashing.

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

@@ -425,65 +425,6 @@ On the server side Just create a Spring Boot application and annotate it with `@
 
 Spring Cloud provides a `spring-cloud-starter-turbine-amqp` that has all the dependencies you need to get a Turbine AMQP server running. You need Java 8 to run the app because it is Netty-based.
 
-[[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.
-
-Example spring boot app
-
-[source,java,indent=0]
-----
-@Configuration
-@ComponentScan
-@EnableAutoConfiguration
-@EnableEurekaClient
-@FeignClientScan
-public class Application {
-
-    public static void main(String[] args) {
-        SpringApplication.run(Application.class, args);
-    }
-
-}
-----
-
-.StoreClient.java
-[source,java,indent=0]
-----
-@FeignClient("stores")
-public interface StoreClient {
-    @RequestMapping(method = RequestMethod.GET, value = "/stores")
-    List<Store> getStores();
-
-    @RequestMapping(method = RequestMethod.POST, value = "/stores/{storeId}", consumes = "application/json")
-    Store update(@PathParameter("storeId") Long storeId, Store store);
-}
-----
-
-In the `@FeignClient` annotation the String value ("stores" above) is
-the arbitrary name of the client, used to create a configuration
-prefix (see <<spring-cloud-ribbon,below for details of Ribbon
-support>>).
-
-[[spring-cloud-feign-without-eureka]]
-=== Example: How to Use Feign Without Eureka
-
-Eureka is a convenient way to abstract the discovery of remote servers
-so you don't have to hard code their URLs in clients, but if you
-prefer not to use it, Ribbon and Feign are still quite
-amenable. Suppose you have declared a Feign client as above for
-"stores", and Eureka is not in use (and not even on the
-classpath). You should find that the Ribbon client defaults to a
-configured server list, and you can supply the configuration like this
-
-.application.yml
-----
-stores:
-  ribbon:
-    listOfServers: example.com,google.com
-----
-
 [[spring-cloud-ribbon]]
 == Client Side Load Balancer: Ribbon
 
@@ -505,8 +446,7 @@ annotation). Spring Cloud creates a new ensemble as an
 You can configure some bits of a Ribbon client using external
 properties in `<client>.ribbon.*`, which is no different than using
 the Netflix APIs natively, except that you can use Spring Boot
-configuration files (example
-<<spring-cloud-feign-without-eureka,above>>). The native options can
+configuration files. The native options can
 be inspected as static fields in `CommonClientConfigKey` (part of
 ribbon-core).
 
@@ -561,6 +501,24 @@ populates the list of servers from Eureka.  It also replaces the `IPing`
 interface with `NIWSDiscoveryPing` which delegates to Eureka to determine if
 a server is up.
 
+[[spring-cloud-ribbon-without-eureka]]
+=== Example: How to Use Ribbon Without Eureka
+
+Eureka is a convenient way to abstract the discovery of remote servers
+so you don't have to hard code their URLs in clients, but if you
+prefer not to use it, Ribbon and Feign are still quite
+amenable. Suppose you have declared a `@RibbonClient` for "stores",
+and Eureka is not in use (and not even on the classpath). The Ribbon
+client defaults to a configured server list, and you can supply the
+configuration like this
+
+.application.yml
+----
+stores:
+  ribbon:
+    listOfServers: example.com,google.com
+----
+
 === Using the Ribbon API Directly
 
 You can also use the `LoadBalancerClient` directly. Example:
@@ -603,6 +561,55 @@ physical address. See
 {github-code}/spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/ribbon/RibbonAutoConfiguration.java[RibbonAutoConfiguration]
 for details of how the `RestTemplate` is set up.
 
+[[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.
+
+Example spring boot app
+
+[source,java,indent=0]
+----
+@Configuration
+@ComponentScan
+@EnableAutoConfiguration
+@EnableEurekaClient
+@EnableFeignClients
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+}
+----
+
+.StoreClient.java
+[source,java,indent=0]
+----
+@FeignClient("stores")
+public interface StoreClient {
+    @RequestMapping(method = RequestMethod.GET, value = "/stores")
+    List<Store> getStores();
+
+    @RequestMapping(method = RequestMethod.POST, value = "/stores/{storeId}", consumes = "application/json")
+    Store update(@PathParameter("storeId") Long storeId, Store store);
+}
+----
+
+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
+(absolute value or just a hostname).
+
+The Ribbon 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>>).
+
 == External Configuration: Archaius
 
 https://github.com/Netflix/archaius[Archaius] is the Netflix client side configuration library.  It is the library used by all of the Netflix OSS components for configuration.  Archaius is an extension of the http://commons.apache.org/proper/commons-configuration[Apache Commons Configuration] project.  It allows updates to configuration by either polling a source for changes or for a source to push changes to the client.  Archaius uses Dynamic<Type>Property classes as handles to properties.

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignAutoConfiguration.java

@@ -19,14 +19,8 @@ package org.springframework.cloud.netflix.feign;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration;
-import org.springframework.cloud.netflix.feign.ribbon.FeignRibbonClient;
-import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
-import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 
-import com.netflix.loadbalancer.ILoadBalancer;
-
-import feign.Client;
 import feign.Feign;
 
 /**
@@ -39,13 +33,4 @@ import feign.Feign;
 @EnableFeignClients
 public class FeignAutoConfiguration {
 
-	@ConditionalOnClass(ILoadBalancer.class)
-	@Configuration
-	protected static class RibbonClientConfiguration {
-		@Bean
-		public Client feignRibbonClient(SpringClientFactory factory) {
-			return new FeignRibbonClient(factory);
-		}
-	}
-
 }

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignClient.java

@@ -36,16 +36,20 @@ import java.lang.annotation.Target;
 public @interface FeignClient {
 
 	/**
-	 * The serviceId if loadbalance is true, or an absolute URL otherwise There is no need
-	 * to prefix serviceId with http://.
+	 * The serviceId with optional protocol prefix. Synonym for {@link #serviceId()
+	 * serviceId}. Either serviceId or url must be specified but not both.
 	 */
-	String value();
+	String value() default "";
 
 	/**
-	 * Set to true if calls should be load balanced (assuming a load balancer is
-	 * available). If no load balancer is available this flag is ignored (and hence the
-	 * {@link #value() value} should be an absolute URL).
+	 * The serviceId with optional protocol prefix. Synonym for {@link #value() value}.
+	 * Either serviceId or url must be specified but not both.
 	 */
-	boolean loadbalance() default true;
+	String serviceId() default "";
+
+	/**
+	 * An absolute URL or resolvable hostname (the protocol is optional).
+	 */
+	String url() default "";
 
 }

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

@@ -22,7 +22,10 @@ import lombok.Data;
 import lombok.EqualsAndHashCode;
 
 import org.springframework.beans.factory.FactoryBean;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 import feign.Client;
 import feign.Contract;
@@ -42,13 +45,13 @@ import feign.slf4j.Slf4jLogger;
  */
 @Data
 @EqualsAndHashCode(callSuper = false)
-class FeignClientFactoryBean implements FactoryBean<Object> {
-
-	private boolean loadbalance;
+class FeignClientFactoryBean implements FactoryBean<Object>, InitializingBean {
 
 	private Class<?> type;
 
-	private String schemeName;
+	private String name;
+
+	private String url;
 
 	@Autowired
 	private Decoder decoder;
@@ -80,6 +83,14 @@ class FeignClientFactoryBean implements FactoryBean<Object> {
 	@Autowired(required = false)
 	private List<RequestInterceptor> requestInterceptors;
 
+	@Override
+	public void afterPropertiesSet() throws Exception {
+		if (StringUtils.hasText(this.name)) {
+			Assert.state(!StringUtils.hasText(this.url),
+					"Either value or url can be specified, but not both");
+		}
+	}
+
 	protected Feign.Builder feign() {
 		Feign.Builder builder = Feign.builder()
 				// required values
@@ -118,13 +129,13 @@ class FeignClientFactoryBean implements FactoryBean<Object> {
 
 	@Override
 	public Object getObject() throws Exception {
-		if (!this.schemeName.startsWith("http")) {
-			this.schemeName = "http://" + this.schemeName;
+		if (StringUtils.hasText(this.name) && !this.name.startsWith("http")) {
+			this.name = "http://" + this.name;
 		}
-		if (this.loadbalance) {
-			return loadBalance(feign(), this.type, this.schemeName);
+		if (StringUtils.hasText(this.name)) {
+			return loadBalance(feign(), this.type, this.name);
 		}
-		return feign().target(this.type, this.schemeName);
+		return feign().target(this.type, this.url);
 	}
 
 	@Override

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignClientsConfiguration.java

@@ -16,6 +16,9 @@
 
 package org.springframework.cloud.netflix.feign;
 
+import org.springframework.cloud.netflix.feign.support.SpringDecoder;
+import org.springframework.cloud.netflix.feign.support.SpringEncoder;
+import org.springframework.cloud.netflix.feign.support.SpringMvcContract;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/FeignClientsRegistrar.java

@@ -99,15 +99,34 @@ public class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar,
 		String className = annotationMetadata.getClassName();
 		BeanDefinitionBuilder definition = BeanDefinitionBuilder
 				.genericBeanDefinition(FeignClientFactoryBean.class);
-		definition.addPropertyValue("loadbalance", attributes.get("loadbalance"));
+		validate(attributes);
+		definition.addPropertyValue("url", getUrl(attributes));
+		definition.addPropertyValue("name", getServiceId(attributes));
 		definition.addPropertyValue("type", className);
-		definition.addPropertyValue("schemeName", attributes.get("value"));
 
 		String beanName = StringUtils.uncapitalize(className.substring(className
 				.lastIndexOf(".") + 1));
 		return new BeanDefinitionHolder(definition.getBeanDefinition(), beanName);
 	}
 
+	private void validate(Map<String, Object> attributes) {
+		if (StringUtils.hasText((String) attributes.get("value"))) {
+			Assert.isTrue(!StringUtils.hasText((String) attributes.get("name")),
+					"Either name or value can be specified, but not both");
+		}
+	}
+
+	private String getServiceId(Map<String, Object> attributes) {
+		if (StringUtils.hasText((String) attributes.get("name"))) {
+			return (String) attributes.get("name");
+		}
+		return (String) attributes.get("value");
+	}
+
+	private String getUrl(Map<String, Object> attributes) {
+		return (String) attributes.get("url");
+	}
+
 	protected ClassPathScanningCandidateComponentProvider getScanner() {
 		return new ClassPathScanningCandidateComponentProvider(false) {
 

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

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2013-2015 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.netflix.feign.ribbon;
+
+import org.springframework.boot.autoconfigure.AutoConfigureBefore;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.cloud.netflix.feign.FeignAutoConfiguration;
+import org.springframework.cloud.netflix.ribbon.SpringClientFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.netflix.loadbalancer.ILoadBalancer;
+
+import feign.Client;
+import feign.Feign;
+
+/**
+ * Autoconfiguration to be activated if Feign is in use and needs to be use Ribbon as a
+ * load balancer.
+ *
+ * @author Dave Syer
+ */
+@ConditionalOnClass({ ILoadBalancer.class, Feign.class })
+@Configuration
+@AutoConfigureBefore(FeignAutoConfiguration.class)
+public class FeignRibbonClientAutoConfiguration {
+	@Bean
+	public Client feignRibbonClient(SpringClientFactory factory) {
+		return new FeignRibbonClient(factory);
+	}
+}

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/support/FeignUtils.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.netflix.feign;
+package org.springframework.cloud.netflix.feign.support;
 
 import java.util.ArrayList;
 import java.util.Collection;

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/support/SpringDecoder.java

@@ -14,9 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.netflix.feign;
-
-import static org.springframework.cloud.netflix.feign.FeignUtils.getHttpHeaders;
+package org.springframework.cloud.netflix.feign.support;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -32,6 +30,8 @@ import org.springframework.http.HttpStatus;
 import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.web.client.HttpMessageConverterExtractor;
 
+import static org.springframework.cloud.netflix.feign.support.FeignUtils.getHttpHeaders;
+
 import feign.FeignException;
 import feign.Response;
 import feign.codec.DecodeException;

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/support/SpringEncoder.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.netflix.feign;
+package org.springframework.cloud.netflix.feign.support;
 
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
@@ -24,6 +24,7 @@ import java.util.Collection;
 import javax.inject.Provider;
 
 import lombok.extern.apachecommons.CommonsLog;
+
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
 import org.springframework.http.HttpHeaders;
@@ -33,12 +34,12 @@ import org.springframework.http.converter.HttpMessageConverter;
 
 import com.google.common.base.Charsets;
 
+import static org.springframework.cloud.netflix.feign.support.FeignUtils.getHttpHeaders;
+
 import feign.RequestTemplate;
 import feign.codec.EncodeException;
 import feign.codec.Encoder;
 
-import static org.springframework.cloud.netflix.feign.FeignUtils.getHttpHeaders;
-
 /**
  * @author Spencer Gibb
  */

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/feign/support/SpringMvcContract.java

@@ -14,7 +14,7 @@
  * limitations under the License.
  */
 
-package org.springframework.cloud.netflix.feign;
+package org.springframework.cloud.netflix.feign.support;
 
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;

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

@@ -1,6 +1,7 @@
 org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
 org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration,\
 org.springframework.cloud.netflix.config.EurekaClientConfigServerAutoConfiguration,\
+org.springframework.cloud.netflix.feign.ribbon.FeignRibbonClientAutoConfiguration,\
 org.springframework.cloud.netflix.feign.FeignAutoConfiguration,\
 org.springframework.cloud.netflix.hystrix.HystrixAutoConfiguration,\
 org.springframework.cloud.netflix.eureka.EurekaClientAutoConfiguration,\