我有如下JSP代码，我可以检查javascript代码的运行时，但我无法检查servlet进程的运行时，运行时总是0，我该怎么办？
<%@ page contentType="text/html; charset=UTF-8"%>
<%@ page import="java.util.List"%>
<%@ page import="java.util.ArrayList"%>
<%
long startTime = System.currentTimeMillis();
MyForm myForm = (MyForm) request.getAttribute(ACTION_FORM_KEY);
if(myForm == null) {
myForm = new PsiSearchForm();
}
List<Object> myList = myForm.getMyList();
if(myList == null) {
myList = new ArrayList<Object>();
}
long endTime = System.currentTimeMillis();
long runTime = endTime - startTime;
%>
<html>
...
</form>
</body>
<script language="JavaScript" type="text/JavaScript">
console.time('my_form.jsp');
// javascript process
console.timeEnd('my_form.jsp');
console.log("Select My List time: " + <%=runTime%>);
</script>
</html>
尝试使用 System.nanoTime();
来自甲骨文
long startTime = System.nanoTime();
// ... the code being measured ...
long estimatedTime = System.nanoTime() - startTime;