A.protected void doGet（HttpServletRequest reg，HttpServletResponse res） throws Servlet Exception ，java.io.IOException
B.protected void doPost（HttpServletRequest reg，HttpServletResponse res） throws Servlet Exception，java.io.IOException
C.protected void doHead（HttpServletRequest reg，HttpServletResponse res） throws Servlet Exception，java.io.IOException
D.protected void doReceive（HttpServletRequest reg，HttpServletResponse res） throws ServletException，java.io.IOException