STOMP client session supports sending ack/nack

Issue: SPR-14208

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/DefaultStompSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -310,6 +310,23 @@ public class DefaultStompSession implements ConnectionHandlingStompSession {
 		return subscription;
 	}
 
+	@Override
+	public Receiptable acknowledge(String messageId, boolean consumed) {
+		StompHeaders stompHeaders = new StompHeaders();
+		stompHeaders.setId(messageId);
+
+		String receiptId = checkOrAddReceipt(stompHeaders);
+		Receiptable receiptable = new ReceiptHandler(receiptId);
+
+		StompCommand command = (consumed ? StompCommand.ACK : StompCommand.NACK);
+		StompHeaderAccessor accessor = createHeaderAccessor(command);
+		accessor.addNativeHeaders(stompHeaders);
+		Message<byte[]> message = createMessage(accessor, null);
+		execute(message);
+
+		return receiptable;
+	}
+
 	private void unsubscribe(String id) {
 		StompHeaderAccessor accessor = createHeaderAccessor(StompCommand.UNSUBSCRIBE);
 		accessor.setSubscriptionId(id);

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompSession.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -86,6 +86,18 @@ public interface StompSession {
 	 */
 	Subscription subscribe(StompHeaders headers, StompFrameHandler handler);
 
+	/**
+	 * Send an acknowledgement whether a message was consumed or not resulting
+	 * in an ACK or NACK frame respectively.
+	 * <p><strong>Note:</strong> to use this when subscribing you must set the
+	 * {@link StompHeaders#setAck(String) ack} header to "client" or
+	 * "client-individual" in order ot use this.
+	 * @param messageId the id of the message
+	 * @param consumed whether the message was consumed or not
+	 * @return a Receiptable for tracking events
+	 */
+	Receiptable acknowledge(String messageId, boolean consumed);
+
 	/**
 	 * Disconnect the session by sending a DISCONNECT frame.
 	 */

spring-messaging/src/test/java/org/springframework/messaging/simp/stomp/DefaultStompSessionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -491,6 +491,42 @@ public class DefaultStompSessionTests {
 		assertEquals(subscription.getSubscriptionId(), stompHeaders.getId());
 	}
 
+	@Test
+	public void ack() throws Exception {
+
+		this.session.afterConnected(this.connection);
+		assertTrue(this.session.isConnected());
+
+		String messageId = "123";
+		this.session.acknowledge(messageId, true);
+
+		Message<byte[]> message = this.messageCaptor.getValue();
+		StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
+		assertEquals(StompCommand.ACK, accessor.getCommand());
+
+		StompHeaders stompHeaders = StompHeaders.readOnlyStompHeaders(accessor.getNativeHeaders());
+		assertEquals(stompHeaders.toString(), 1, stompHeaders.size());
+		assertEquals(messageId, stompHeaders.getId());
+	}
+
+	@Test
+	public void nack() throws Exception {
+
+		this.session.afterConnected(this.connection);
+		assertTrue(this.session.isConnected());
+
+		String messageId = "123";
+		this.session.acknowledge(messageId, false);
+
+		Message<byte[]> message = this.messageCaptor.getValue();
+		StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
+		assertEquals(StompCommand.NACK, accessor.getCommand());
+
+		StompHeaders stompHeaders = StompHeaders.readOnlyStompHeaders(accessor.getNativeHeaders());
+		assertEquals(stompHeaders.toString(), 1, stompHeaders.size());
+		assertEquals(messageId, stompHeaders.getId());
+	}
+
 	@Test
 	public void receiptReceived() throws Exception {