Cookie重名问题处理

常用 API --- Cookie重名问题

1)、Cookie 重名时，可能执行覆盖操作

2)、什么情况下不覆盖?

A、站点不同时

B、setPath("路径");//路径不同时，Cookie 可以重名

 

步骤详解:

创建一个servlet命名为PathDemo用来缓存cookie

在类中给所有cookie变量设置路径,如果单一设置会将所有的路径都打印出来

在servlet中运行,http://localhost:8080/PathDemo,将路径存进cookie

 

此时请求头里不会有数据,因为每个变量都加了路径,地址栏里没有设置路径

创建servlet测试类打印信息

http://localhost:8080/BBB/TWoServlet此时控制台会打印出指定路径的值,路径和配置文件路径URL一致

打印出来222

 

 

详细代码:

public class PathDemo extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
Cookie c1 = new Cookie("A","111");
//设置 PATH
Cookie c2 = new Cookie("B","222");
Cookie c3 = new Cookie("B","333");
c1.setPath("/AAA");
c2.setPath("/BBB");
c3.setPath("/CCC");
response.addCookie(c1);
response.addCookie(c2);
response.addCookie(c3);
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
}

 

 

public class TWoServlet extends HttpServlet
public void doGet(HttpServletRequest req,HttpServletResponse res){
Cookie[] cookies = req.getCookies();
if(cookies!=null && cookies.length>0){
for (Cookie cookie : cookies) {
System.out.println(cookie.getName()+"  "+cookie.getValue());
}
}
}
public void doPost(HttpServletRequest req,HttpServletResponse res){
doGet(req, res);
}
}

 

  day34Demo01_Cookie
 
    index.html
    index.htm
    index.jsp
    default.html
    default.htm
    default.jsp
 
 
   
    PathDemo
    PathDemo
    cn.itcast.web.servlet.PathDemo
 
 
    PathDemo
    /PathDemo
   
 
   
    TWoServlet
    cn.itcast.web.servlet.TWoServlet
 
 
    TWoServlet
    /BBB/TWoServlet