This minor bug is located in org.jboss.soa.esb.samples.quickstart.httpgateway.MyAction. The process method is defined in following way:
public String printHttpRequestInfo(@BodyParam byte httpPayload
But this way the http body is not extracted from the request. The correct httpPayload type should be String.
I think it is good to fix this because (unfortunately) this is the only place where @BodyParam anotation is used.