Make metrics aspect conditional on Spring AOP

Also changes pointcut to use the interface so you don't need
proxyTargetClass=true.

Fixes gh-636

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/metrics/MetricsInterceptorConfiguration.java

@@ -13,10 +13,12 @@
 
 package org.springframework.cloud.netflix.metrics;
 
+import org.aspectj.lang.JoinPoint;
 import org.springframework.beans.factory.config.BeanPostProcessor;
 import org.springframework.boot.actuate.metrics.reader.MetricReader;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
@@ -47,13 +49,22 @@ public class MetricsInterceptorConfiguration {
 	}
 
 	@Configuration
+	@ConditionalOnClass(JoinPoint.class)
+	@ConditionalOnProperty(value = "spring.aop.enabled", havingValue = "true", matchIfMissing = true)
 	@ConditionalOnBean({ RestTemplate.class })
-	static class MetricsRestTemplateConfiguration {
+	static class MetricsRestTemplateAspectConfiguration {
+
 		@Bean
 		RestTemplateUrlTemplateCapturingAspect restTemplateUrlTemplateCapturingAspect() {
 			return new RestTemplateUrlTemplateCapturingAspect();
 		}
 
+	}
+
+	@Configuration
+	@ConditionalOnBean({ RestTemplate.class })
+	static class MetricsRestTemplateConfiguration {
+
 		@Bean
 		MetricsClientHttpRequestInterceptor spectatorLoggingClientHttpRequestInterceptor() {
 			return new MetricsClientHttpRequestInterceptor();
@@ -64,14 +75,17 @@ public class MetricsInterceptorConfiguration {
 				final MetricsClientHttpRequestInterceptor interceptor) {
 			return new BeanPostProcessor() {
 				@Override
-				public Object postProcessBeforeInitialization(Object bean, String beanName) {
+				public Object postProcessBeforeInitialization(Object bean,
+						String beanName) {
 					return bean;
 				}
 
 				@Override
-				public Object postProcessAfterInitialization(Object bean, String beanName) {
-					if (bean instanceof RestTemplate)
+				public Object postProcessAfterInitialization(Object bean,
+						String beanName) {
+					if (bean instanceof RestTemplate) {
 						((RestTemplate) bean).getInterceptors().add(interceptor);
+					}
 					return bean;
 				}
 			};

spring-cloud-netflix-core/src/main/java/org/springframework/cloud/netflix/metrics/RestTemplateUrlTemplateCapturingAspect.java

@@ -1,11 +1,11 @@
 /*
  * 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.
@@ -25,7 +25,7 @@ import org.aspectj.lang.annotation.Aspect;
  */
 @Aspect
 public class RestTemplateUrlTemplateCapturingAspect {
-	@Around("execution(* org.springframework.web.client.RestTemplate.*(String, ..))")
+	@Around("execution(* org.springframework.web.client.RestOperations+.*(String, ..))")
 	void captureUrlTemplate(ProceedingJoinPoint joinPoint) throws Throwable {
 		try {
 			String urlTemplate = (String) joinPoint.getArgs()[0];