spring - save camel messages between routes -

we use spring dsl define camel routes. in 1 case message headers disappear. our design requires audit trail debug issues, , prove messages moving designed. use , reference audit processor create message file name 2 headers, 1 constant, other unique variable. can't use setheader in case of variable one. here generic example includes commented attempts failed:

  <route id="msg_in">       <from uri="direct:msg_in" />       <wiretap ref="audit" processorref="auditpreprocessor" />       <to uri="direct:to_json" />   </route>    <route id="to_json">       <from uri="direct:to_json" />       <!-- below seemed have failed -->       <!-- <setproperty propertyname="saveid"> -->       <!--  <simple>${in.header.uniqueid}</simple> -->       <!-- </setproperty> -->       <bean ref="jdbcprocessor1" />       <!-- headers still exist here -->       <bean ref="tojson1" />       <!-- headers still exist here, , wiretap on next line works -->       <wiretap ref="audit" processorref="auditpreprocessor" />       <bean ref="tojson" />       <!-- message headers not here need set them again ? -->       <setheader headername="hdr1">           <constant>update1</constant>       </setheader>       <!-- <setheader headername="uniqueid"> -->       <!--  <simple>${exchangeproperty:saveid}</simple> ... didn't work -->       <!--  <simple>${properties:saveid}</simple>    ... didn't work -->       <!-- </setheader> -->       <to uri="direct:msg_out" />   </route>   <route id="msg_out">       <from uri="direct:msg_out" />       <!-- try wiretap here no headers, saved file null-null        , gets continually overwritten, no usable audit trail -->   </route> 

i spent considerable time trying find right way in spring xml, no luck yet.

thanks in advance if can help.