IE禁用Cookie后的session处理

IE禁用Cookie后解决方案：ＵＲＬ重写

购物车案例《IE禁用Cookie后》

购物界面ShowBook.servlet

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=utf-8");
        PrintWriter out = response.getWriter();
        
        //先死后活
        out.println("<h1>欢迎购买</h1>");
        
        out.println("oracle书<a href='/myCart/BuyBookCl?id=3&name=oracle' >点击购买</a></br>");

        //取出Db
        ArrayList<Book> mydb=Db.getDb();
        
        //访问一些session
        request.getSession();
        
        for(Book book:mydb){
            String url=response.encodeURL("/myCart/BuyBookCl?id="+book.getId());
            
            //我们希望href ="/myCart/BuyBookCl?id=1&"
            out.println(book.getName()+"----"+book.getPrice()+"<a href='"+url+"' >点击购买</a></br>");
        }
        
    }

BuyBookCl.servlet

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html;charset=utf-8");
        @SuppressWarnings("unused")
        PrintWriter out = response.getWriter();
        //request.getAttribute(name)接受的servlet与本身（request里面放置的属性）
        
        //浏览器发过来的(http协议相关的)
        
         
        String id=request.getParameter("id");
        Book bookinfo=Db.getBookById(id);
        HttpSession session=request.getSession();
        

        HashMap<String,Book> hm=(HashMap<String,Book>)session.getAttribute("myBooks");
        //如果第一次购物al=null
        if(hm==null){     
            hm=new LinkedHashMap<String,Book>();
            Book book=new Book();
            book.setId(id);
            book.setName(bookinfo.getName());
            book.setNum(1);
             hm.put(id,book);
             //al放到session中
             session.setAttribute("myBooks", hm);
        }else{
            //判断hm中是否有该书
            if(hm.containsKey(id)){
                //表示购买过一次
                //取出
                Book book=hm.get(id);
                int bookNum=book.getNum();
                book.setNum(bookNum+1);
            }else{
                Book book=new Book();
                book.setId(id);
                book.setName(bookinfo.getName());
                book.setNum(1);
                 hm.put(id,book);
            }
            //更新
            session.setAttribute("myBooks", hm);
        }
        //跳转到购物车
        request.getRequestDispatcher("/ShowMyCart").forward(request, response);     
    }

ShowMyCart.servlet

public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {

        response.setContentType("text/html；charset=utf-8");
        PrintWriter out = response.getWriter();
        
        HashMap<String,Book> myBooks=(HashMap<String,Book>)request.getSession().getAttribute("myBooks"); 
         
        out.println("你的购物车有以下书籍:</br>");
        //out.println(myBooks);
        
        //遍历hashMap
        Iterator iterator=myBooks.keySet().iterator();
        
        while(iterator.hasNext()){
            
            String key=(String)iterator.next();
            
            Book book=myBooks.get(key);
            out.println(book.getName()+"----"+book.getNum()+"</br>");
        }
        
        out.println("购物车的总价是");
        
        //这里我们也需要地址重写
        String url=response.encodeURL("/myCart/ShowBook");
        
        out.println("<a href='"+url+"'>返回购物大厅</a>");
    }