Adding missing commit from #1457

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

+/*
+ *
+ *  * 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.netflix.feign.ribbon;
+
+import java.net.URI;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.springframework.cloud.client.ServiceInstance;
+import org.springframework.cloud.client.loadbalancer.InterceptorRetryPolicy;
+import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryContext;
+import org.springframework.cloud.client.loadbalancer.LoadBalancedRetryPolicy;
+import org.springframework.cloud.client.loadbalancer.ServiceInstanceChooser;
+import org.springframework.http.HttpRequest;
+import org.springframework.retry.RetryContext;
+
+/**
+ * @author Ryan Baxter
+ */
+public class FeignRetryPolicy extends InterceptorRetryPolicy {
+	private HttpRequest request;
+	private String serviceId;
+	public FeignRetryPolicy(HttpRequest request, LoadBalancedRetryPolicy policy, ServiceInstanceChooser serviceInstanceChooser, String serviceName) {
+		super(request, policy, serviceInstanceChooser, serviceName);
+		this.request = request;
+		this.serviceId = serviceName;
+	}
+
+	@Override
+	public boolean canRetry(RetryContext context) {
+		/*
+		 * In InterceptorRetryPolicy.canRetry we ask the LoadBalancer to choose a server if one is not
+		 * set in the retry context and then return true.  RetryTemplat calls the canRetry method of
+		 * the policy even on its first execution.  So the fact that we didnt have a service instance set
+		 * in the RetryContext signaled that it was the first execution and we should return true.
+		 *
+		 * In the Feign scenario, Feign as actually already queried the load balancer for a service instance
+		 * and we set that service instance in the context when we call the open method of the policy.  So in
+		 * the Feign case we just return true if the retry count is 0 indicating we haven't yet made a failed
+		 * request.
+		 */
+		if(context.getRetryCount() == 0) {
+			return true;
+		}
+		return super.canRetry(context);
+	}
+
+	@Override
+	public RetryContext open(RetryContext parent) {
+		/*
+		 * With Feign (unlike Ribbon) the request already has the URI for the service instance
+		 * we are going to make the request to, so extract that information and set the service
+		 * instance in the context.  In the Ribbon scenario the URI in the request object still has
+		 * the service id so we choose and set the service instance later on.
+		 */
+		LoadBalancedRetryContext context = new LoadBalancedRetryContext(parent, this.request);
+		context.setServiceInstance(new FeignRetryPolicyServiceInstance(serviceId, request));
+		return context;
+	}
+
+	class FeignRetryPolicyServiceInstance implements ServiceInstance {
+
+		private String serviceId;
+		private HttpRequest request;
+		private Map<String, String> metadata;
+
+		FeignRetryPolicyServiceInstance(String serviceId, HttpRequest request) {
+			this.serviceId = serviceId;
+			this.request = request;
+			this.metadata = new HashMap<String, String>();
+		}
+
+		@Override
+		public String getServiceId() {
+			return serviceId;
+		}
+
+		@Override
+		public String getHost() {
+			return request.getURI().getHost();
+		}
+
+		@Override
+		public int getPort() {
+			return request.getURI().getPort();
+		}
+
+		@Override
+		public boolean isSecure() {
+			return "https".equals(request.getURI().getScheme());
+		}
+
+		@Override
+		public URI getUri() {
+			return request.getURI();
+		}
+
+		@Override
+		public Map<String, String> getMetadata() {
+			return metadata;
+		}
+	}
+}
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