如何用cookie验证session

1、什么是状态管理，状态管理即对数据的管理，Cookie和session最大的区别是session将数据保存在服务器端，Cookie将数据保存在客户端；

2、public class CodeServlet extends HttpServlet{   @Overrideprotected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {        request.setCharacterEncoding("utf-8");      response.setContentType("text/html;charset=utf-8");      PrintWriter out=response.getWriter();  

3、  //添加cookie      Cookie c=new Cookie("city",URLEncoder.encode("合肥","utf-8"));         response.addCookie(c);         Cookie[] cookies=request.getCookies();         for(Cookie c2:cookies){          String value=c2.getValue();          out.print("name:"+c2.getName()+"value:"+URLDecoder.decode(value,"utf-8"));         }         out.close();   }}

4、  public class FindCookieServlet extends HttpServlet{   @Overrideprotected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {      request.setCharacterEncoding("utf-8");      response.setContentType("text/html;charset=utf-8");         PrintWriter out=response.getWriter();

5、//        Cookie c1=new Cookie("city","Hefei");//        response.addCookie(c1);         //查找cookie         Cookie[] cookies=request.getCookies();         if (cookies!=null) {   for(Cookie c:cookies){    out.print("Cookie名："+c.getName()+";Cookie值："+c.getValue()+"<br>");   }  }}

6、         if(cookies==null){         out.print("<h1>没有找到相关的cookie信息</h1>");          }         out.close();   }