polishing

If no converter is found, the MessageConversionException now contains
the message instance that could not be handled

Issue: SPR-11817

spring-messaging/src/main/java/org/springframework/messaging/core/AbstractMessageReceivingTemplate.java

@@ -67,9 +67,9 @@ public abstract class AbstractMessageReceivingTemplate<D> extends AbstractMessag
 		MessageConverter messageConverter = getMessageConverter();
 		T value = (T) messageConverter.fromMessage(message, targetClass);
 		if (value == null) {
-			throw new MessageConversionException("Unable to convert payload='"
+			throw new MessageConversionException(message, "Unable to convert payload='"
 					+ message.getPayload() + "' to type='" + targetClass
-					+ "', converter=[" + messageConverter + "]");
+					+ "', converter=[" + messageConverter + "]", null);
 		}
 		return value;
 	}

spring-messaging/src/test/java/org/springframework/messaging/core/MessageReceivingTemplateTests.java

@@ -29,8 +29,7 @@ import org.springframework.messaging.converter.MessageConversionException;
 import org.springframework.messaging.support.GenericMessage;
 
 import static org.hamcrest.CoreMatchers.isA;
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertSame;
+import static org.junit.Assert.*;
 
 import java.io.Writer;
 
@@ -118,10 +117,13 @@ public class MessageReceivingTemplateTests {
 		this.template.setDefaultDestination("home");
 		this.template.setReceiveMessage(expected);
 		this.template.setMessageConverter(new GenericMessageConverter(new DefaultConversionService()));
-
-		thrown.expect(MessageConversionException.class);
-		thrown.expectMessage("payload");
-		this.template.receiveAndConvert(Writer.class);
+		try {
+			this.template.receiveAndConvert(Writer.class);
+		}
+		catch (MessageConversionException e) {
+			assertTrue("Invalid exception message '"+e.getMessage()+"'", e.getMessage().contains("payload"));
+			assertSame(expected, e.getFailedMessage());
+		}
 	}