Reuse JmsTemplate's MessageConverter in JmsMessagingTemplate

This commit makes sure that any custom MessageConverter set in a
JmsTemplate used by a JmsMessagingTemplate is reused as the payload
converter of the message.

Issue: SPR-15965

Author: snicoll

spring-jms/src/main/java/org/springframework/jms/core/JmsMessagingTemplate.java

@@ -52,6 +52,8 @@ public class JmsMessagingTemplate extends AbstractMessagingTemplate<Destination>
 
 	private MessageConverter jmsMessageConverter = new MessagingMessageConverter();
 
+	private boolean converterSet;
+
 	@Nullable
 	private String defaultDestinationName;
 
@@ -131,6 +133,7 @@ public JmsTemplate getJmsTemplate() {
 	public void setJmsMessageConverter(MessageConverter jmsMessageConverter) {
 		Assert.notNull(jmsMessageConverter, "MessageConverter must not be null");
 		this.jmsMessageConverter = jmsMessageConverter;
+		this.converterSet = true;
 	}
 
 	/**
@@ -162,6 +165,10 @@ public String getDefaultDestinationName() {
 	@Override
 	public void afterPropertiesSet() {
 		Assert.notNull(this.jmsTemplate, "Property 'connectionFactory' or 'jmsTemplate' is required");
+		if (!this.converterSet && this.jmsTemplate.getMessageConverter() != null) {
+			((MessagingMessageConverter) this.jmsMessageConverter)
+					.setPayloadConverter(this.jmsTemplate.getMessageConverter());
+		}
 	}
 
 	private JmsTemplate obtainJmsTemplate() {

spring-jms/src/main/java/org/springframework/jms/support/converter/MessagingMessageConverter.java

@@ -55,6 +55,15 @@ public MessagingMessageConverter() {
 		this(new SimpleMessageConverter(), new SimpleJmsHeaderMapper());
 	}
 
+	/**
+	 * Create an instance with the specific payload converter.
+	 * @param payloadConverter the payload converter to use
+	 * @since 4.3.12
+	 */
+	public MessagingMessageConverter(MessageConverter payloadConverter) {
+		this(payloadConverter, new SimpleJmsHeaderMapper());
+	}
+
 	/**
 	 * Create an instance with the specified payload converter and
 	 * header mapper.

spring-jms/src/test/java/org/springframework/jms/core/JmsMessagingTemplateTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -36,13 +36,14 @@
 import org.mockito.Captor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
-import org.mockito.invocation.InvocationOnMock;
 import org.mockito.stubbing.Answer;
 
+import org.springframework.beans.DirectFieldAccessor;
 import org.springframework.jms.InvalidDestinationException;
 import org.springframework.jms.MessageNotReadableException;
 import org.springframework.jms.StubTextMessage;
 import org.springframework.jms.support.converter.MessageConverter;
+import org.springframework.jms.support.converter.MessagingMessageConverter;
 import org.springframework.jms.support.converter.SimpleMessageConverter;
 import org.springframework.jms.support.destination.DestinationResolutionException;
 import org.springframework.messaging.Message;
@@ -83,6 +84,47 @@ public void validateJmsTemplate() {
 		assertSame(this.jmsTemplate, this.messagingTemplate.getJmsTemplate());
 	}
 
+	@Test
+	public void payloadConverterIsConsistentConstructor() {
+		MessageConverter messageConverter = mock(MessageConverter.class);
+		given(this.jmsTemplate.getMessageConverter()).willReturn(messageConverter);
+		JmsMessagingTemplate messagingTemplate = new JmsMessagingTemplate(this.jmsTemplate);
+		messagingTemplate.afterPropertiesSet();
+		assertPayloadConverter(messagingTemplate, messageConverter);
+	}
+
+	@Test
+	public void payloadConverterIsConsistentSetter() {
+		MessageConverter messageConverter = mock(MessageConverter.class);
+		given(this.jmsTemplate.getMessageConverter()).willReturn(messageConverter);
+		JmsMessagingTemplate messagingTemplate = new JmsMessagingTemplate();
+		messagingTemplate.setJmsTemplate(this.jmsTemplate);
+		messagingTemplate.afterPropertiesSet();
+		assertPayloadConverter(messagingTemplate, messageConverter);
+	}
+
+	@Test
+	public void customConverterAlwaysTakesPrecedence() {
+		MessageConverter messageConverter = mock(MessageConverter.class);
+		given(this.jmsTemplate.getMessageConverter()).willReturn(messageConverter);
+		MessageConverter customMessageConverter = mock(MessageConverter.class);
+		JmsMessagingTemplate messagingTemplate = new JmsMessagingTemplate();
+		messagingTemplate.setJmsMessageConverter(
+				new MessagingMessageConverter(customMessageConverter));
+		messagingTemplate.setJmsTemplate(this.jmsTemplate);
+		messagingTemplate.afterPropertiesSet();
+		assertPayloadConverter(messagingTemplate, customMessageConverter);
+	}
+
+	private void assertPayloadConverter(JmsMessagingTemplate messagingTemplate,
+			MessageConverter messageConverter) {
+		MessageConverter jmsMessageConverter = messagingTemplate.getJmsMessageConverter();
+		assertNotNull(jmsMessageConverter);
+		assertEquals(MessagingMessageConverter.class, jmsMessageConverter.getClass());
+		assertSame(messageConverter, new DirectFieldAccessor(jmsMessageConverter)
+				.getPropertyValue("payloadConverter"));
+	}
+
 	@Test
 	public void send() {
 		Destination destination = new Destination() {};