Detect Order on target class as well

Previously, the `@Order` annotation was managed in an inconsistent way
when placed at the implementation level. For simple beans, it was
discovered properly but wasn't for beans requiring a proxy.

OrderComparator.SourceProvider now explicitly allows to return several
order sources; the default implementation returns not only the factory
method (if  any) but also the target class if it happens to be different
from the class of the bean.

Issue: SPR-12636

spring-context/src/test/java/org/springframework/context/annotation/Spr12636Tests.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2002-2015 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.context.annotation;
+
+import java.util.List;
+
+import org.junit.After;
+import org.junit.Test;
+
+import org.springframework.aop.support.AopUtils;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.core.annotation.Order;
+import org.springframework.scheduling.annotation.Async;
+import org.springframework.scheduling.annotation.EnableAsync;
+import org.springframework.stereotype.Component;
+
+import static org.junit.Assert.*;
+
+/**
+ * @author Stephane Nicoll
+ */
+public class Spr12636Tests {
+
+	private ConfigurableApplicationContext context;
+
+	@After
+	public void closeContext() {
+		if (this.context != null) {
+			this.context.close();
+		}
+	}
+
+	@Test
+	public void orderOnImplementation() {
+		this.context = new AnnotationConfigApplicationContext(
+				UserServiceTwo.class, UserServiceOne.class, UserServiceCollector.class);
+		UserServiceCollector bean = this.context.getBean(UserServiceCollector.class);
+		assertSame(context.getBean("serviceOne", UserService.class), bean.userServices.get(0));
+		assertSame(context.getBean("serviceTwo", UserService.class), bean.userServices.get(1));
+
+	}
+
+	@Test
+	public void orderOnImplementationWithProxy() {
+		this.context = new AnnotationConfigApplicationContext(
+				UserServiceTwo.class, UserServiceOne.class, UserServiceCollector.class, AsyncConfig.class);
+
+		// Validate those beans are indeed wrapped by a proxy
+		UserService serviceOne = this.context.getBean("serviceOne", UserService.class);
+		UserService serviceTwo = this.context.getBean("serviceTwo", UserService.class);
+		assertTrue(AopUtils.isAopProxy(serviceOne));
+		assertTrue(AopUtils.isAopProxy(serviceTwo));
+
+		UserServiceCollector bean = this.context.getBean(UserServiceCollector.class);
+		assertSame(serviceOne, bean.userServices.get(0));
+		assertSame(serviceTwo, bean.userServices.get(1));
+	}
+
+	@Configuration
+	@EnableAsync
+	static class AsyncConfig {
+	}
+
+
+	@Component
+	static class UserServiceCollector {
+
+		public final List<UserService> userServices;
+
+		@Autowired
+		UserServiceCollector(List<UserService> userServices) {
+			this.userServices = userServices;
+		}
+	}
+
+	interface UserService {
+
+		void doIt();
+	}
+
+	@Component("serviceOne")
+	@Order(1)
+	static class UserServiceOne implements UserService {
+
+		@Async
+		@Override
+		public void doIt() {
+
+		}
+	}
+
+	@Component("serviceTwo")
+	@Order(2)
+	static class UserServiceTwo implements UserService {
+
+		@Async
+		@Override
+		public void doIt() {
+
+		}
+	}
+}