JavaWeb-request acquisition request related method path

A first example, I give a complete access address:

　　http://localhost:8080/Demo01/AServlet?username="xxx"&passwd="XXX"

　　　(1) protocol name is http, the name of the method to obtain the agreement:

　　　　request.getScheme();

　　　(2) server name is localhotst, the method of acquiring the server name:

　　　　request.getServerName();

　　　(3) The server interface is 8080, acquiring server interface method:

　　　　 request.getServerPort();

　　　(4) the project name is Demo01, get the name of the project method:

　　　　request.getContextPath();

　　　(5) Servlet path / AServlet, acquisition method:

　　　　request.getServletPath();

　　　(6) Parameter part username = "xxx" & passwd = "XXX", acquisition method:

　　　　request.getQueryString();

　　　(7) URI is / Demo01 / AServlet, acquisition method:

　　　　request.getRequestURI();

　　　(8) URL is http: // localhost: 8080 / Demo01 / AServlet, acquisition method

　　　　request.getRequestURL();

　　　　　　

　　II. Schematic