currently we customized org.apache.servicecomb.transport.rest.vertx.RestBodyHandler 1.disable upload feature when uploadDir is null, this is a general requirement 2.wrap some exceptions to JavaChassis exception， this is not a general requirement
if there is only customization 1, maybe we can try to raise a PR to vertx otherwise we always forget to merge latest vertx logic to our code. maybe we can confirm if customization 2 is necessary.
