StrutsMockHttpServletRequest request = new StrutsMockHttpServletRequest();
ActionContext.getContext().setValueStack(stack);
request.setAttribute(ServletActionContext.STRUTS_VALUESTACK_KEY, stack);
// create the mock page context
pageContext = new MockPageContext();
pageContext.setRequest(request);
pageContext.setJspWriter(new MockJspWriter());
// associate the tag with the mock page request
tag.setPageContext(pageContext);