More robust instantiation in SpringClientFactory

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

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.netflix.ribbon;
 
+import java.lang.reflect.Constructor;
+
 import org.springframework.beans.BeanUtils;
 import org.springframework.cloud.context.named.NamedContextFactory;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
@@ -80,33 +82,30 @@ public class SpringClientFactory extends NamedContextFactory<RibbonClientSpecifi
 	static <C> C instantiateWithConfig(AnnotationConfigApplicationContext context,
 										Class<C> clazz, IClientConfig config) {
 		C result = null;
-		if (IClientConfigAware.class.isAssignableFrom(clazz)) {
-			IClientConfigAware obj = (IClientConfigAware) BeanUtils.instantiate(clazz);
-			obj.initWithNiwsConfig(config);
-			@SuppressWarnings("unchecked")
-			C value = (C) obj;
-			result = value;
+		
+		try {
+			Constructor<C> constructor = clazz.getConstructor(IClientConfig.class);
+			result = constructor.newInstance(config);
+		} catch (Throwable e) {
+			// Ignored
 		}
-		else {
-			try {
-				if (clazz.getConstructor(IClientConfig.class) != null) {
-					result = clazz.getConstructor(IClientConfig.class)
-							.newInstance(config);
-				}
-				else {
-					result = BeanUtils.instantiate(clazz);
-				}
+		
+		if (result == null) {
+			result = BeanUtils.instantiate(clazz);
+			
+			if (result instanceof IClientConfigAware) {
+				((IClientConfigAware) result).initWithNiwsConfig(config);
 			}
-			catch (Throwable ex) {
-				// NOPMD
+			
+			if (context != null) {
+				context.getAutowireCapableBeanFactory().autowireBean(result);
 			}
 		}
-		if (context != null) {
-			context.getAutowireCapableBeanFactory().autowireBean(result);
-		}
+		
 		return result;
 	}
 
+	@Override
 	public <C> C getInstance(String name, Class<C> type) {
 		C instance = super.getInstance(name, type);
 		if (instance != null) {

spring-cloud-netflix-core/src/test/java/org/springframework/cloud/netflix/ribbon/SpringClientFactoryTests.java

@@ -23,9 +23,13 @@ import org.springframework.cloud.netflix.archaius.ArchaiusAutoConfiguration;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
 import com.netflix.client.DefaultLoadBalancerRetryHandler;
+import com.netflix.client.IClientConfigAware;
+import com.netflix.client.config.DefaultClientConfigImpl;
+import com.netflix.client.config.IClientConfig;
 import com.netflix.niws.client.http.RestClient;
 import com.sun.jersey.client.apache4.ApacheHttpClient4;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.Assert.assertEquals;
 import static org.springframework.boot.test.util.EnvironmentTestUtils.addEnvironment;
 
@@ -35,6 +39,31 @@ import static org.springframework.boot.test.util.EnvironmentTestUtils.addEnviron
  */
 public class SpringClientFactoryTests {
 
+	public static class ClientConfigInjectedByConstructor {
+		
+		private IClientConfig clientConfig;
+
+		public ClientConfigInjectedByConstructor(IClientConfig clientConfig) {
+			this.clientConfig = clientConfig;
+		}
+	}
+	
+	public static class ClientConfigInjectedByInitMethod implements IClientConfigAware {
+		
+		private IClientConfig clientConfig;
+
+		@Override
+		public void initWithNiwsConfig(IClientConfig clientConfig) {
+			this.clientConfig = clientConfig;
+		}
+	}
+	
+	public static class NoClientConfigAware {
+		
+		public NoClientConfigAware() {
+			// no client config
+		}
+	}
 
 	@Test
 	public void testConfigureRetry() {
@@ -65,4 +94,25 @@ public class SpringClientFactoryTests {
 				.getHttpClient().getParams().getParameter(ClientPNames.COOKIE_POLICY));
 		factory.destroy();
 	}
+	
+	@Test
+	public void testInstantiateWithConfigInjectByConstructor() {
+		IClientConfig clientConfig = new DefaultClientConfigImpl();
+		ClientConfigInjectedByConstructor instance = SpringClientFactory.instantiateWithConfig(ClientConfigInjectedByConstructor.class, clientConfig);
+		assertThat(instance.clientConfig).isSameAs(clientConfig);
+	}
+	
+	@Test
+	public void testInstantiateWithConfigInjectedByInitMethod() {
+		IClientConfig clientConfig = new DefaultClientConfigImpl();
+		ClientConfigInjectedByInitMethod instance = SpringClientFactory.instantiateWithConfig(ClientConfigInjectedByInitMethod.class, clientConfig);
+		assertThat(instance.clientConfig).isSameAs(clientConfig);
+	}
+	
+	@Test
+	public void testInstantiateWithoutConfig() {
+		IClientConfig clientConfig = new DefaultClientConfigImpl();
+		NoClientConfigAware instance = SpringClientFactory.instantiateWithConfig(NoClientConfigAware.class, clientConfig);
+		assertThat(instance).isNotNull();
+	}
 }