The gear filter determines which gear a request pertains to. The gear filter is invoked in the Portal Filter Chain after the PortalServerFilter. It is responsible for setting up the gearId and gearMode query parameters used when encoding gear URLs with the encodeGearURL method. These default to paf_gear_id and paf_gm and are set by the gearIdParameterName and gearModeParameterName init parameters, respectively.
