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>");
}