CookieUtil

package com.css.common.util;

import java.util.HashMap;
import java.util.Map;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
* Description: CookieUtil <br/>
* Copyright: Copyright (c) 2010 <br/>
* Create DateTime: 2010-6-28 下午05:25:45 <br/>
*
* @version 1.0 <br/>
*/
public final class CookieUtil {
 
 private CookieUtil() {
  throw new UnsupportedOperationException();
 }
 
   /**
     * 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);
    }
   
    /**
     * 获取cookie的值
     * @param request
     * @param name cookie的名称
     * @return
     */
    public static String getCookieByName(HttpServletRequest request, String name) {
     Map<String, Cookie> cookieMap = CookieUtil.readCookieMap(request);
        if (cookieMap.containsKey(name)) {
            Cookie cookie = cookieMap.get(name);
            return cookie.getValue();
        }else{
            return null;
        }
    }
   
    /**
     * 读取Cookie 映射成Map 只供内部方法调用
     * @param request
     * @return
     */
    private 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;
    }
}