spring-projectsGH-1473: Switch to CompletableFuture

Resolves spring-projects#1473

Given the stability of the project, it was simplest to copy the `AsyncRabbitTemplate`
rather than adding a lot of conditional code.

**2.4.x only; I will submit a separate PR for main**

spring-amqp/src/main/java/org/springframework/amqp/core/AsyncAmqpTemplate2.java

@@ -0,0 +1,205 @@
+/*
+ * Copyright 2020 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
+ *
+ *      https://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.amqp.core;
+
+import java.util.concurrent.CompletableFuture;
+
+import org.springframework.core.ParameterizedTypeReference;
+
+/**
+ * Classes implementing this interface can perform asynchronous send and
+ * receive operations using {@link CompletableFuture}s.
+ *
+ * @author Gary Russell
+ * @since 2.4.7
+ *
+ */
+public interface AsyncAmqpTemplate2 {
+
+	/**
+	 * Send a message to the default exchange with the default routing key. If the message
+	 * contains a correlationId property, it must be unique.
+	 * @param message the message.
+	 * @return the {@link CompletableFuture}.
+	 */
+	CompletableFuture<Message> sendAndReceive(Message message);
+
+	/**
+	 * Send a message to the default exchange with the supplied routing key. If the message
+	 * contains a correlationId property, it must be unique.
+	 * @param routingKey the routing key.
+	 * @param message the message.
+	 * @return the {@link CompletableFuture}.
+	 */
+	CompletableFuture<Message> sendAndReceive(String routingKey, Message message);
+
+	/**
+	 * Send a message to the supplied exchange and routing key. If the message
+	 * contains a correlationId property, it must be unique.
+	 * @param exchange the exchange.
+	 * @param routingKey the routing key.
+	 * @param message the message.
+	 * @return the {@link CompletableFuture}.
+	 */
+	CompletableFuture<Message> sendAndReceive(String exchange, String routingKey, Message message);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * default routing key.
+	 * @param object the object to convert.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(Object object);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * provided routing key.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(String routingKey, Object object);
+
+	/**
+	 * Convert the object to a message and send it to the provided exchange and
+	 * routing key.
+	 * @param exchange the exchange.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(String exchange, String routingKey, Object object);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * default routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(Object object, MessagePostProcessor messagePostProcessor);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * provided routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(String routingKey, Object object,
+			MessagePostProcessor messagePostProcessor);
+
+	/**
+	 * Convert the object to a message and send it to the provided exchange and
+	 * routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param exchange the exchange
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceive(String exchange, String routingKey, Object object,
+			MessagePostProcessor messagePostProcessor);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * default routing key.
+	 * @param object the object to convert.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(Object object, ParameterizedTypeReference<C> responseType);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * provided routing key.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(String routingKey, Object object,
+			ParameterizedTypeReference<C> responseType);
+
+	/**
+	 * Convert the object to a message and send it to the provided exchange and
+	 * routing key.
+	 * @param exchange the exchange.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(String exchange, String routingKey, Object object,
+			ParameterizedTypeReference<C> responseType);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * default routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(Object object, MessagePostProcessor messagePostProcessor,
+			ParameterizedTypeReference<C> responseType);
+
+	/**
+	 * Convert the object to a message and send it to the default exchange with the
+	 * provided routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(String routingKey, Object object,
+			MessagePostProcessor messagePostProcessor, ParameterizedTypeReference<C> responseType);
+
+	/**
+	 * Convert the object to a message and send it to the provided exchange and
+	 * routing key after invoking the {@link MessagePostProcessor}.
+	 * If the post processor adds a correlationId property, it must be unique.
+	 * @param exchange the exchange
+	 * @param routingKey the routing key.
+	 * @param object the object to convert.
+	 * @param messagePostProcessor the post processor.
+	 * @param responseType the response type.
+	 * @param <C> the expected result type.
+	 * @return the {@link CompletableFuture}.
+	 */
+	<C> CompletableFuture<C> convertSendAndReceiveAsType(String exchange, String routingKey, Object object,
+			MessagePostProcessor messagePostProcessor, ParameterizedTypeReference<C> responseType);
+
+}

spring-rabbit/src/main/java/org/springframework/amqp/rabbit/AsyncRabbitTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -89,7 +89,9 @@
  * @author Artem Bilan
  *
  * @since 1.6
+ * @deprecated in favor of {@link AsyncRabbitTemplate2}.
  */
+@Deprecated
 public class AsyncRabbitTemplate implements AsyncAmqpTemplate, ChannelAwareMessageListener, ReturnsCallback,
 		ConfirmCallback, BeanNameAware, SmartLifecycle {