cookie

 /**
  *
  * 获取cookie的值
  * @param name:cookie的名称
  */
 public static String getCookieValueByName(HttpServletRequest request, String name) {
  Map<String, Cookie> cookieMap = WebUtil.readCookieMap(request);
  if (cookieMap.containsKey(name)) {
   Cookie cookie = (Cookie) cookieMap.get(name);
   return cookie.getValue();
  } else {
   return null;
  }
 }

 /**
  * 添加cookie
  *
  * @param response
  * @param name
  *            cookie的名称
  * @param value
  *            cookie的值
  * @param maxAge
  *            cookie存放的时间(以秒为单位,假如存放三天,即3*24*60*60; 如果值为0,cookie将随浏览器关闭而清除)
  */
 public static void addCookie(HttpServletResponse response, String name, String value, int maxAge) {
  Cookie cookie = new Cookie(name, value);
  cookie.setPath("/");
  if (maxAge > 0)
   cookie.setMaxAge(maxAge);
  response.addCookie(cookie);
 }

 protected static Map<String, Cookie> readCookieMap(HttpServletRequest request) {
  Map<String, Cookie> cookieMap = new HashMap<String, Cookie>();
  Cookie[] cookies = request.getCookies();
  if (null != cookies) {
   for (int i = 0; i < cookies.length; i++) {
    cookieMap.put(cookies[i].getName(), cookies[i]);
   }
  }
  return cookieMap;
 }

 

 /**
  * 根据cookie名字删除对应的cookie
  *
  * @param name
  */
 public static void delCookie(HttpServletRequest request, HttpServletResponse response,
   String name) {
  Cookie[] cookies = request.getCookies();
  if (cookies != null) {
   for (Cookie c : cookies) {
    if (c.getName().equals(name)) {
     c.setMaxAge(0);
     c.setPath("/"); //这里也很重要：必须设置和添加时设置的路径相同
     response.addCookie(c);
     System.out.println(c.getName());
     break;
    }
   }
  }
 }