Polish

Review bd093eb to provide a generic type on `JmsResponse`

Issue: SPR-13133

Author: snicoll

spring-jms/src/main/java/org/springframework/jms/listener/adapter/AbstractAdaptableMessageListener.java

@@ -267,7 +267,7 @@ protected void handleResult(Object result, Message request, Session session) {
 	 */
 	protected Message buildMessage(Session session, Object result) throws JMSException {
 		Object content = (result instanceof JmsResponse
-				? ((JmsResponse) result).getResponse() : result);
+				? ((JmsResponse<?>) result).getResponse() : result);
 
 		MessageConverter converter = getMessageConverter();
 		if (converter != null) {
@@ -308,7 +308,7 @@ protected void postProcessResponse(Message request, Message response) throws JMS
 	private Destination getResponseDestination(Message request, Message response, Session session, Object result)
 			throws JMSException {
 		if (result instanceof JmsResponse) {
-			JmsResponse jmsResponse = (JmsResponse) result;
+			JmsResponse<?> jmsResponse = (JmsResponse) result;
 			Destination destination = jmsResponse.resolveDestination(getDestinationResolver(), session);
 			if (destination != null) {
 				return destination;

spring-jms/src/main/java/org/springframework/jms/listener/adapter/JmsResponse.java

@@ -50,10 +50,11 @@
  * @since 4.2
  * @see org.springframework.jms.annotation.JmsListener
  * @see org.springframework.messaging.handler.annotation.SendTo
+ * @param <T> the type of the response
  */
-public class JmsResponse {
+public class JmsResponse<T> {
 
-	private final Object response;
+	private final T response;
 
 	private final Object destination;
 
@@ -62,7 +63,7 @@ public class JmsResponse {
 	 * @param response the content of the result
 	 * @param destination the destination
 	 */
-	protected JmsResponse(Object response, Object destination) {
+	protected JmsResponse(T response, Object destination) {
 		Assert.notNull(response, "Result must not be null");
 		this.response = response;
 		this.destination = destination;
@@ -71,32 +72,42 @@ protected JmsResponse(Object response, Object destination) {
 	/**
 	 * Create a {@link JmsResponse} targeting the queue with the specified name.
 	 */
-	public static JmsResponse forQueue(Object result, String queueName) {
+	public static <T> JmsResponse<T> forQueue(T result, String queueName) {
 		Assert.notNull(queueName, "Queue name must not be null");
-		return new JmsResponse(result, new DestinationNameHolder(queueName, false));
+		return new JmsResponse<T>(result, new DestinationNameHolder(queueName, false));
 	}
 
 	/**
 	 * Create a {@link JmsResponse} targeting the topic with the specified name.
 	 */
-	public static JmsResponse forTopic(Object result, String topicName) {
+	public static <T> JmsResponse<T> forTopic(T result, String topicName) {
 		Assert.notNull(topicName, "Topic name must not be null");
-		return new JmsResponse(result, new DestinationNameHolder(topicName, true));
+		return new JmsResponse<T>(result, new DestinationNameHolder(topicName, true));
 	}
 
 	/**
 	 * Create a {@link JmsResponse} targeting the specified {@link Destination}.
 	 */
-	public static JmsResponse forDestination(Object result, Destination destination) {
+	public static <T> JmsResponse<T> forDestination(T result, Destination destination) {
 		Assert.notNull(destination, "Destination must not be null");
-		return new JmsResponse(result, destination);
+		return new JmsResponse<T>(result, destination);
 	}
 
-
-	public Object getResponse() {
-		return response;
+	/**
+	 * Return the content of the response.
+	 */
+	public T getResponse() {
+		return this.response;
 	}
 
+	/**
+	 * Resolve the {@link Destination} to use for this instance. The {@link DestinationResolver}
+	 * and {@link Session} can be used to resolve a destination at runtime.
+	 * @param destinationResolver the destination resolver to use if necessary
+	 * @param session the session to use, if necessary
+	 * @return the {@link Destination} to use
+	 * @throws JMSException if the DestinationResolver failed to resolve the destination
+	 */
 	public Destination resolveDestination(DestinationResolver destinationResolver, Session session)
 			throws JMSException {
 

spring-jms/src/test/java/org/springframework/jms/listener/adapter/JmsResponseTests.java

@@ -52,7 +52,7 @@ public void resolveDestinationForQueue() throws JMSException {
 		Destination destination = mock(Destination.class);
 
 		given(destinationResolver.resolveDestinationName(session, "myQueue", false)).willReturn(destination);
-		JmsResponse jmsResponse = JmsResponse.forQueue("foo", "myQueue");
+		JmsResponse<String> jmsResponse = JmsResponse.forQueue("foo", "myQueue");
 		Destination actual = jmsResponse.resolveDestination(destinationResolver, session);
 		assertSame(destination, actual);
 	}

spring-jms/src/test/java/org/springframework/jms/listener/adapter/MessagingMessageListenerAdapterTests.java

@@ -285,21 +285,21 @@ public Message<String> echo(Message<String> input) {
 					.build();
 		}
 
-		public JmsResponse replyPayloadToQueue(Message<String> input) {
+		public JmsResponse<String> replyPayloadToQueue(Message<String> input) {
 			return JmsResponse.forQueue(input.getPayload(), "queueOut");
 		}
 
-		public JmsResponse replyPayloadToTopic(Message<String> input) {
+		public JmsResponse<String> replyPayloadToTopic(Message<String> input) {
 			return JmsResponse.forTopic(input.getPayload(), "topicOut");
 		}
 
-		public JmsResponse replyPayloadToDestination(Message<String> input) {
+		public JmsResponse<String> replyPayloadToDestination(Message<String> input) {
 			return JmsResponse.forDestination(input.getPayload(),
 					input.getHeaders().get("destination", Destination.class));
 		}
 
-		public JmsResponse replyPayloadNoDestination(Message<String> input) {
-			return new JmsResponse(input.getPayload(), null);
+		public JmsResponse<String> replyPayloadNoDestination(Message<String> input) {
+			return new JmsResponse<>(input.getPayload(), null);
 		}
 
 		public void fail(String input) {