Throw a proper exception if no convert is found

Prior to this commit, no exception was raised if a message could not
be converted to the requested payload because no suitable converter
were found.

This commit adds an explicit check if the converted payload is null.

Issue: SPR-11817

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

@@ -17,13 +17,23 @@
 package org.springframework.messaging.core;
 
 import org.junit.Before;
+import org.junit.Rule;
 import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+import org.springframework.core.convert.ConversionFailedException;
+import org.springframework.core.convert.support.DefaultConversionService;
 import org.springframework.messaging.Message;
+import org.springframework.messaging.converter.GenericMessageConverter;
+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 java.io.Writer;
+
 /**
  * Unit tests for receiving operations in {@link AbstractMessagingTemplate}.
  *
@@ -33,6 +43,9 @@ import static org.junit.Assert.assertSame;
  */
 public class MessageReceivingTemplateTests {
 
+	@Rule
+	public final ExpectedException thrown = ExpectedException.none();
+
 	private TestMessagingTemplate template;
 
 
@@ -88,6 +101,29 @@ public class MessageReceivingTemplateTests {
 		assertSame("payload", payload);
 	}
 
+	@Test
+	public void receiveAndConvertFailed() {
+		Message<?> expected = new GenericMessage<Object>("not a number test");
+		this.template.setReceiveMessage(expected);
+		this.template.setMessageConverter(new GenericMessageConverter(new DefaultConversionService()));
+
+		thrown.expect(MessageConversionException.class);
+		thrown.expectCause(isA(ConversionFailedException.class));
+		this.template.receiveAndConvert("somewhere", Integer.class);
+	}
+
+	@Test
+	public void receiveAndConvertNoConverter() {
+		Message<?> expected = new GenericMessage<Object>("payload");
+		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);
+	}
+
 
 
 	private static class TestMessagingTemplate extends AbstractMessagingTemplate<String> {