To read request params :
Sample request : http://localhost:8280/services/MyService?param1=val1¶m2=val2
<property name="PARAM1" expression="tokenize(substring-after(syn:get-property('To'),'param1='),'&')"/>
<property name="PARAM1" expression="tokenize(substring-after(syn:get-property('To'),'param2='),'&')"/>