Any tag present to pass null value for restriction parameter ?

[boy18nj]

If I use this- collatRptCatgryMapList.typeId.setMtr(null)

I can see in the restriction parameter value it is being passed as 0 value.

<s:selectItems id="selected" var="_curr"
       value="#{collatRptCatgryTypeList.resultList}"
       label="#{_curr.catgryTypeDesc}" itemValue="#{_curr.catgryTypeId}"
       noSelectionLabel="All Report Category Type">
      </s:selectItems>

If I select here noSelectionLabel value, then the value passed is null. So i am trying to mimic this behaviour of passing null value. Is it somehow possible?

Note that mtr is of type Integer.