CompositeData and TabularData are printed with toString in the Manager JMXProxy. It makes the result hard to read (for a human) and to grep. CompositeData could be represented as {key1=value1, key2=value2,...}. TabularData could be printed like arrays.
PR sent (#67)
Thanks for the patch. It has been applied to 9.0.c for 9.0.0.M23 onwards. I'm not planning on back-porting it since, while users should not depend on the exact format out this sort of output, experience is that they do.