Spring Cloud Stream attaches, by default, a contentType header to outbound messages.

[jprateekvmware]

Spring Cloud Stream attaches, by default, a contentType header to outbound messages.

http://docs.spring.io/spring-cloud-stream/docs/Brooklyn.RELEASE/reference/html/contenttypemanagement.html

Do i have the option to disable having contentType appended in the messages ?

contentType
"text/plain"originalContentType2"application/x-java-object;type=java.util.HashMap"{"a

[olegz]

Hmm, not sure I fully understand. Are you saying you want to modify the content of the message by appending 'contentType' to the end of the content of the actual message?

[jprateekvmware]

I just want the payload to be published without contentType information, only JSON content
contentType
"text/plain"originalContentType2"application/x-java-object;type=java.util.HashMap"{"attributes":{"type":"Account","url":"/services/data

[ilayaperumalg]

@jprateekvmware The contentType here reflects the content type used by the corresponding binder during serializing the payload and this content type will be used when de-serializing the payload at the consumer side. The originalContentType is the actual contentType of the message which will be updated as contentType to the message after de-serialization at the consumer.

I think you need spring.cloud.stream.bindings.<channelName>.producer.headerMode=raw in your case where you handle the message headers natively.

[olegz]

@jprateekvmware some of us have been discussing it internally and it would probably help if you share your use case a bit so we can understand why you don't want the header information. The embedded content type is primarily for internal use to be able to deal with messaging middleware that does not play well with headers (e.g., Kafka), but it should be completely transparent to you by the time you actually see the Message<Payload, Headers>, so personally I am still not sure what you are trying to accomplish.

[jprateekvmware]

@ilayaperumalg not working
@olegz one of our consumer is not able to parse the JSON because of the header present. I have it working fine with no Issues with Most of the Sink. I am addressing the issue for one of our consumer of kafka queue, who is not within the SCS workflow.

return s.decode('utf-8')
File "/usr/lib64/python2.6/encodings/utf_8.py", line 16, in decode
return codecs.utf_8_decode(input, errors, True)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xff in position 0: invalid start byte

Can you please point me to the code snippet /filename where the headers are getting appended, For the time being I have hard stop to close it and I would have property added to disable it.

[olegz]

Ok, I think that makes a bit more sense to me now - ". . .who is not within the SCS workflow. . ." since that is where the transparency I was talking about is gone.
You may want to try org.springframework.cloud.stream.binder.EmbeddedHeaderUtils

MessageValues mv = EmbeddedHeaderUtils.extractHeaders(msg);
byte[] rawPayloadNoHeaders = mv.getPayload();

While the above may allow you to parse out ray payload, I am still wondering why suggestion from @ilayaperumalg is not working for you? I was assuming that by doing so the message would have no embedded headers.

[olegz]

Also, to better understand where everything is happening you may wan to look at org.springframework.cloud.stream.binder.AbstractMessageChannelBinder

[mbogoevici]

@jprateekvmware can you explain what is not working when you set spring.cloud.stream.bindings.<channelName>.producer.headerMode=raw ? It disables the embedding of headers (including contentType) into messages. For example, spring.cloud.stream.bindings.output.producer.headerMode=raw .

[jprateekvmware]

Passing it at the deployment time.
app..spring.cloud.stream.bindings.output.content-type=application/json
app..spring.cloud.stream.bindings.output.producer.headerMode=raw

Below is the error message.
Raw mode supports only application/octet-stream content typeclass java.lang.String

[mbogoevici]

What version are you using? This was as issue ( #855 ) that has been fixed since Chelsea.RELEASE.

[jprateekvmware]

Thanks I saw that , let me try with Chelsea.RELEASE release

[jprateekvmware]

Now its working @ilayaperumalg
Thanks everyone for your support and quick resolution.
have got it closed. Got little struck with common NoSuchMethodError with spring now a days but have it resolved.

Publishing pom snippet for anyone to put up dependencies. would be closing the issue.

org.springframework.boot spring-boot-starter-parent 1.5.3.RELEASE

<properties>
	<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
	<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
	<java.version>1.8</java.version>
	<spring-cloud-dependencies.version>Dalston.RELEASE</spring-cloud-dependencies.version>
</properties>

<dependencies>
	<!-- https://mvnrepository.com/artifact/org.apache.kafka/kafka-clients -->
	<dependency>
		<groupId>org.apache.kafka</groupId>
		<artifactId>kafka-clients</artifactId>
		<version>0.10.2.1</version>
	</dependency>

	<dependency>
		<groupId>org.springframework.cloud</groupId>
		<artifactId>spring-cloud-stream-binder-kafka</artifactId>
	</dependency>

[jprateekvmware]

Fixed based on recommendation from the Spring team.