多项选择题 A developer has created a web application that includes a servlet for each use case in the application.These servlets have become rather difficult to maintain because the request processing methods havebecome very large. There is also common processing code in many servlets because these use cases arevery similar. Which two design patterns can be used together to refactor and simplify this web application？（）

多项选择题 You need to store a floating point number，called Tsquare，in the session scope. Which two code snippetsallow you to retrieve this value？（）

多项选择题 Given an HttpServletRequest request： 22.String id = request.getParameter（"jsessionid"）； 23.// insert code here 24.String name = （String） session.getAttribute（"name"）； Which three can be placed at line 23 to retrieve anexisting HttpSession object？（）