Use of JSP sessionscope domain

demand ： When adding a page to return , The search criteria do not show ,
reason ： I am visiting List On the page , Use requestScope The search criteria returned by the field . When I go to add pages , And then back List On the page , It does not trigger the query background List Page method .
resolvent ： Instead of sessionScope To store the request conditions . Use HashSet To add the data of query criteria .

<div class="cnmRowBox cnmRowBoxfRole cnmRowBoxfRole_w27">
	<dl class="cnm-select cnm-selectNet">
		<dt>
			<span> <liferay-ui:message key="Access.Computer.Room.DataCenter" />：</span>
		</dt>
		<dd>
			<select class="cnmSelt cnmputrState vewlog" id="selectSearchType">
				<option value=""><liferay-ui:message key="all" /></option>
				<c:forEach items="${sessionScope.searchDataList}" var="item">
					<option value="${item}">${item}</option>
				</c:forEach>
			</select>
		</dd>
	</dl>
</div>