Request parameter How to find whether a parameter exists in the request object (Servlets)

Question :Request parameter How to find whether a parameter exists in the request
object? (Servlets)

Answer :1.boolean hasFoo = !(request.getParameter("foo") == null ||
request.getParameter("foo").equals(""));
2. boolean hasParameter =
request.getParameterMap().contains(theParameter);
(which works in Servlet 2.3+)