JSP programming best practice: Use Commerce-specific maps to access request parameters

HCL Commerce provides the following Commerce-specific versions of the implicit JSP objects param and paramValues to facilitate access to decrypted HTTP request parameters:

A Map object that maps the name of a request parameter to its single String value.
Optional: A Map object that maps the name of a request parameter to a String array of all values for that parameter.
To get an object such as WCParamValues, you must set WCParamMode="1" in the instance XML file. See technote for more information.

Although, in many cases, the standard implicit objects param and paramValues provide equivalent functionality to their Commerce-specific counterparts, the former are not guaranteed to work properly in the case of encrypted parameters, and hence WCParam and WCParamValues should be consistently used in store JSP pages.

As an example, to output the value of the catalogId request parameter, use the following statement:

<c:out value="${WCParam.catalogId}" />


The Commerce-specific maps cannot be used to access additional parameters that are passed into a dynamically included page (that is, a page included by means of the <jsp:include> or the <c:import> tag).

Thus, in the following example, SomePage.jsp and SomeOtherPage.jsp will not be able to access showSubCategory through WCParam or WCParamValues and will have to do so through param or paramValues instead:

<jsp:include page="SomePage.jsp" flush="true">
  <jsp:param name="showSubCategory" value="true" />
<c:import url="SomeOtherPage.jsp">
  <c:param name="showSubCategory" value="false" />