GH-1352: Spring Integration 5.5 Compatibility

Refactoring to allow Spring Integration 5.5 to be used with both
2.3.x and 2.4.x.

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/listener/MessageListenerContainer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2014-2020 the original author or authors.
+ * Copyright 2014-2021 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.
@@ -17,7 +17,9 @@
 package org.springframework.amqp.rabbit.listener;
 
 import org.springframework.amqp.core.MessageListener;
+import org.springframework.beans.factory.InitializingBean;
 import org.springframework.context.SmartLifecycle;
+import org.springframework.lang.Nullable;
 
 /**
  * Internal abstraction used by the framework representing a message
@@ -27,7 +29,7 @@
  * @author Gary Russell
  * @since 1.4
  */
-public interface MessageListenerContainer extends SmartLifecycle {
+public interface MessageListenerContainer extends SmartLifecycle, InitializingBean {
 
 	/**
 	 * Setup the message listener to use. Throws an {@link IllegalArgumentException}
@@ -57,4 +59,23 @@ default boolean isConsumerBatchEnabled() {
 		return false;
 	}
 
+	/**
+	 * Set auto startup.
+	 * @param autoStart true to auto start.
+	 * @since 2.3.10
+	 */
+	void setAutoStartup(boolean autoStart);
+
+	/**
+	 * Get the message listener.
+	 * @return The message listener object.
+	 * @since 2.3.10
+	 */
+	@Nullable
+	Object getMessageListener();
+
+	@Override
+	default void afterPropertiesSet() {
+	}
+
 }