wrap SpringLBClientFactory in a CachingLBClientFactory so LBClients are reused.

fixes gh-240

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

@@ -0,0 +1,47 @@
+/*
+ * 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 feign.ribbon.LBClient;
+import feign.ribbon.LBClientFactory;
+import org.springframework.util.ConcurrentReferenceHashMap;
+
+import java.util.Map;
+
+/**
+ * LBClientFactory that caches entries created.
+ * @author Spencer Gibb
+ */
+public class CachingLBClientFactory implements LBClientFactory {
+
+	private volatile Map<String, LBClient> cache = new ConcurrentReferenceHashMap<>();
+	private final LBClientFactory delegate;
+
+	public CachingLBClientFactory(LBClientFactory delegate) {
+		this.delegate = delegate;
+	}
+
+	@Override
+	public LBClient create(String clientName) {
+		if (cache.containsKey(clientName)) {
+			return cache.get(clientName);
+		}
+		LBClient client = delegate.create(clientName);
+		cache.put(clientName, client);
+		return client;
+	}
+}

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

@@ -16,7 +16,6 @@
 
 package org.springframework.cloud.netflix.feign.ribbon;
 
-import feign.ribbon.LBClientFactory;
 import feign.ribbon.RibbonClient;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureBefore;
@@ -47,13 +46,18 @@ public class FeignRibbonClientAutoConfiguration {
 	private SpringClientFactory factory;
 
 	@Bean
-	public LBClientFactory lbClientFactory() {
+	public SpringLBClientFactory springLBClientFactory() {
 		return new SpringLBClientFactory(factory);
 	}
 
+	@Bean
+	public CachingLBClientFactory cachingLBClientFactory() {
+		return new CachingLBClientFactory(springLBClientFactory());
+	}
+
 	@Bean
 	@ConditionalOnMissingBean
 	public Client feignRibbonClient() {
-		return RibbonClient.builder().lbClientFactory(lbClientFactory()).build();
+		return RibbonClient.builder().lbClientFactory(cachingLBClientFactory()).build();
 	}
 }

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

@@ -0,0 +1,78 @@
+/*
+ * 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 static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
+
+import com.netflix.client.config.CommonClientConfigKey;
+import com.netflix.client.config.DefaultClientConfigImpl;
+import com.netflix.client.config.IClientConfig;
+import feign.ribbon.LBClient;
+import feign.ribbon.LBClientFactory;
+import org.junit.Before;
+import org.junit.Test;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+/**
+ * @author Spencer Gibb
+ */
+public class CachingLBClientFactoryTests {
+
+	@Mock
+	private LBClientFactory delegate;
+
+	private CachingLBClientFactory factory;
+
+	@Before
+	public void init() {
+		MockitoAnnotations.initMocks(this);
+
+		IClientConfig config = new DefaultClientConfigImpl();
+		config.set(CommonClientConfigKey.ConnectTimeout, 1000);
+		config.set(CommonClientConfigKey.ReadTimeout, 500);
+
+		LBClient client1 = LBClient.create(null, config);
+		LBClient client2 = LBClient.create(null, config);
+
+		when(delegate.create("client1")).thenReturn(client1);
+		when(delegate.create("client2")).thenReturn(client2);
+
+		factory = new CachingLBClientFactory(delegate);
+	}
+
+	@Test
+	public void delegateCreatesWhenMissing() {
+		LBClient client = factory.create("client1");
+		assertNotNull("client was null", client);
+
+		verify(delegate, times(1)).create("client1");
+	}
+
+	@Test
+	public void cacheWorks() {
+		LBClient client = factory.create("client2");
+		assertNotNull("client was null", client);
+
+		client = factory.create("client2");
+		assertNotNull("client was null", client);
+
+		verify(delegate, times(1)).create("client2");
+	}
+
+}