INT-3535: Fix JmsHM to not override properties

JIRA: https://jira.spring.io/browse/INT-3535

Previously when `DefaultJmsHeaderMapper` overrided values, which had been able to be populated by the `MessageConverter`.

Since `MessageConverter` result has a precedence which is closer to JMS, skip those custom `MessageHeaders` which already has been populated by `MessageConverter`

spring-integration-jms/src/main/java/org/springframework/integration/jms/DefaultJmsHeaderMapper.java

@@ -51,6 +51,7 @@ import org.springframework.util.StringUtils;
  *
  * @author Mark Fisher
  * @author Gary Russell
+ * @author Artem Bilan
  */
 public class DefaultJmsHeaderMapper implements JmsHeaderMapper {
 
@@ -140,7 +141,8 @@ public class DefaultJmsHeaderMapper implements JmsHeaderMapper {
 			}
 			Set<String> headerNames = headers.keySet();
 			for (String headerName : headerNames) {
-				if (StringUtils.hasText(headerName) && !headerName.startsWith(JmsHeaders.PREFIX)) {
+				if (StringUtils.hasText(headerName) && !headerName.startsWith(JmsHeaders.PREFIX)
+						&& jmsMessage.getObjectProperty(headerName) == null) {
 					Object value = headers.get(headerName);
 					if (value != null && SUPPORTED_PROPERTY_TYPES.contains(value.getClass())) {
 						try {

spring-integration-jms/src/test/java/org/springframework/integration/jms/DefaultJmsHeaderMapperTests.java

@@ -16,24 +16,35 @@
 
 package org.springframework.integration.jms;
 
+import static org.hamcrest.Matchers.instanceOf;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertSame;
+import static org.junit.Assert.assertThat;
 
 import java.util.Date;
 import java.util.Map;
 
 import javax.jms.Destination;
 import javax.jms.JMSException;
+import javax.jms.Session;
+import javax.jms.TextMessage;
 
 import org.junit.Test;
+import org.mockito.Mockito;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
 
 import org.springframework.integration.IntegrationMessageHeaderAccessor;
 import org.springframework.integration.support.MessageBuilder;
+import org.springframework.jms.support.converter.MappingJackson2MessageConverter;
+import org.springframework.jms.support.converter.MessageType;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageHeaders;
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
+
 /**
  * @author Mark Fisher
  * @author Gary Russell
@@ -497,4 +508,41 @@ public class DefaultJmsHeaderMapperTests {
 		assertEquals("bar", headers.get("foo"));
 	}
 
+
+	@Test
+	public void testJsonHeaderMapping() throws JMSException {
+
+		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
+		converter.setTargetType(MessageType.TEXT);
+		converter.setTypeIdPropertyName("javatype");
+
+		Session session = Mockito.mock(Session.class);
+
+		Mockito.doAnswer(new Answer<TextMessage>() {
+
+			@Override
+			public TextMessage answer(InvocationOnMock invocation) throws Throwable {
+				return new StubTextMessage((String) invocation.getArguments()[0]);
+			}
+
+		}).when(session).createTextMessage(Mockito.anyString());
+
+		javax.jms.Message request = converter.toMessage(new Foo(), session);
+
+		DefaultJmsHeaderMapper mapper = new DefaultJmsHeaderMapper();
+		Map<String, Object> headers = mapper.toHeaders(request);
+
+		javax.jms.Message reply = converter.toMessage("foo", session);
+		mapper.fromHeaders(new MessageHeaders(headers), reply);
+
+		Object result = converter.fromMessage(reply);
+		assertThat(result, instanceOf(String.class));
+	}
+
+
+	@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "javatype")
+	private static class Foo {
+
+	}
+
 }