Java 是如何读取和写入浏览器Cookies的实例详解

/*
 * 该类可以从浏览器请求中提取出cookies并进行对cookis的相关操作
 * 
 */

public class CookiesUtil extends BaseController {
  
  /**
   * 根据名字获取cookie
   * 
   * @param request
   * @param name
   *      cookie名字
   * @return
   */
  public static Cookie getCookieByName(HttpServletRequest request, String name) {
    Map<String, Cookie> cookieMap = ReadCookieMap(request);
    if (cookieMap.containsKey(name)) {
      Cookie cookie = (Cookie) cookieMap.get(name);
      return cookie;
    } else {
      return null;
    }
  }

  /**
   * 将cookie封装到Map里面
   * 
   * @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 (Cookie cookie : cookies) {
        cookieMap.put(cookie.getName(), cookie);
      }
    }
    return cookieMap;
  }

  /**
   * 保存Cookies
   * 
   * @param response
   *      servlet请求
   * @param value
   *      保存值
   * @author jxf
   */
  public static HttpServletResponse setCookie(HttpServletResponse response, String name, String value,int time) {
    // new一个Cookie对象,键值对为参数
    Cookie cookie = new Cookie(name, value);
    // tomcat下多应用共享
    cookie.setPath("/");
    // 如果cookie的值中含有中文时，需要对cookie进行编码，不然会产生乱码
    try {
      URLEncoder.encode(value, "utf-8");
    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    }
    cookie.setMaxAge(time);
    // 将Cookie添加到Response中,使之生效
    response.addCookie(cookie); // addCookie后，如果已经存在相同名字的cookie，则最新的覆盖旧的cookie
    return response;
  }
 

 

/**
    * <p>删除无效cookie</p>
    * <p>无效?1.过时 2.未发布</p>
    * @param request
    * @param response
    * @param list
    */
   private void delectCookieByName(HttpServletRequest request, HttpServletResponse response,String deleteKey) throws NullPointerException {12     Map<String, Cookie> cookieMap = ReadCookieMap(request);17     for (String key : cookieMap.keySet()) {  
       if(key==deleteKey && key.equals(deleteKey)) {
         Cookie cookie = cookieMap.get(key);21         cookie.setMaxAge(0);//设置cookie有效时间为0
         cookie.setPath("/");//不设置存储路径
         response.addCookie(cookie);
       }
      } 
  }