MessageHeaderAccessor.getContentType() should get deal with String value too, rather than rely only casting to MimeType [SPR-12730]

[spring-projects-issues]

Artem Bilan opened SPR-12730 and commented

See the issue in the linked SO question.

Spring Integration AMQP populates content-type headers from AMQP Message headers as String. There are other components in Spring Integration which do the same, e.g. ObjectToJsonTransformer.

From other side AmqpMessageHeaderAccessor has this code:

@Override
public MimeType getContentType() {
	Object value = getHeader(AmqpHeaders.CONTENT_TYPE);
	if (value != null && value instanceof String) {
	return MimeType.valueOf((String) value);
	}
	else {
	return super.getContentType();
        }
}

Looks like would be better to move this code to the core MessageHeaderAccessor and allow for end-application to avoid this transformation:

.setHeader(MessageHeaders.CONTENT_TYPE, amqpMessageHeaderAccessor.getContentType())

Or manual MimeType.valueOf() invocation.

For me this is minor change, so can be backported.

---

Affects: 4.1.4

Reference URL: http://stackoverflow.com/questions/28587286/having-trouble-with-contenttype-going-from-amqp-to-stomp-message

Referenced from: commits dbd353b, 55a14eb

[spring-projects-issues]

Juergen Hoeller commented

I've added defensive code to getId(), getTimestamp() and getContentType(), all doing instanceof checks now and being able to convert a String value if necessary (or even any holder object with a toString() result which happens to be parseable to the desired type).

Juergen

[spring-projects-issues]

Juergen Hoeller commented

Artem Bilan, this is available in the latest 4.1.5 snapshot now. Please give it a try and let me know whether it does the job for you...

Juergen

[spring-projects-issues]

Artem Bilan commented

Juergen Hoeller, I confirm that it works as expected. My test-case looks like:

@Bean                                                                                                                    
@Transformer(inputChannel = "input", outputChannel = "webSocketOutputChannel")                                           
public ObjectToJsonTransformer transformer() {                                                                           
	return new ObjectToJsonTransformer();                                                                                
}                                                                                                                        
                                                                                                                         
@Bean                                                                                                                    
@ServiceActivator(inputChannel = "webSocketOutputChannel")                                                               
public MessageHandler webSocketOutboundMessageHandler() {                                                                
	return new WebSocketOutboundMessageHandler(clientWebSocketContainer(),                                               
			new SubProtocolHandlerRegistry(stompSubProtocolHandler()));                                                  
}         
.....
this.input.send(
          new GenericMessage<Map<String, String>>(Collections.<String, String>singletonMap("foo", Spring")));                                                                                                               

Where ObjectToJsonTransformer populates contentType header as application/json String.

I've tested that with SF 4.2.0-BUILD-SNAPSHOT, but I see that 4.1.5 has the same code change.

Thank you very much!