Support for @Order at the bean declaration level

This commit introduces OrderProvider and OrderProviderComparator, two
interfaces designed to externalize how a collection of element is sorted
according to their order value.

FactoryAwareOrderProvider is an OrderProvider implementation that knows
about the objects to order and the corresponding BeanFactory instance.
This allows to retrieve additional metadata about the actual instances
to sort, such as its factory method.

A @Bean method can now holds an additional @Order to define the order
value that this bean should have when injected as part of a collection
or array.

Issue: SPR-11310

spring-context/src/test/java/org/springframework/context/annotation/spr11310/Spr11310Tests.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright 2002-2014 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.spr11310;
+
+import static org.junit.Assert.*;
+
+import java.util.List;
+
+import org.junit.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.ApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.annotation.Order;
+
+/**
+ *
+ * @author Stephane Nicoll
+ */
+public class Spr11310Tests {
+
+	@Test
+	public void orderedList() {
+		ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);
+		StringHolder holder = context.getBean(StringHolder.class);
+		assertEquals("second", holder.itemsList.get(0));
+		assertEquals("first", holder.itemsList.get(1));
+		assertEquals("unknownOrder", holder.itemsList.get(2));
+	}
+
+	@Test
+	public void orderedArray() {
+		ApplicationContext context = new AnnotationConfigApplicationContext(Config.class);
+		StringHolder holder = context.getBean(StringHolder.class);
+		assertEquals("second", holder.itemsArray[0]);
+		assertEquals("first", holder.itemsArray[1]);
+		assertEquals("unknownOrder", holder.itemsArray[2]);
+	}
+
+
+	@Configuration
+	static class Config {
+
+		@Bean
+		@Order(50)
+		public String first() {
+			return "first";
+		}
+
+		@Bean
+		public String unknownOrder() {
+			return "unknownOrder";
+		}
+
+		@Bean
+		@Order(5)
+		public String second() {
+			return "second";
+		}
+
+		@Bean
+		public StringHolder stringHolder() {
+			return new StringHolder();
+		}
+
+	}
+
+
+	private static class StringHolder {
+		@Autowired
+		private List<String> itemsList;
+
+		@Autowired
+		private String[] itemsArray;
+
+	}
+}