Java Cookie工具类

1.Cookie跨域

　　Cookie不能跨顶级域名访问，但是二级域名可以共享Cookie，所以要实现跨域，有一定的局限性。

2.代码

　　

package com.DingYu.Cookie;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

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


/**
 * 
 * Cookie 工具类
 *
 */
public final class CookieUtils {

    /**
     * 得到Cookie的值, 不编码
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName) {
        return getCookieValue(request, cookieName, false);
    }

    /**
     * 得到Cookie的值,
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, boolean isDecoder) {
        //获得所有的Cookie
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    //如果true 使用UTF-8 进行解码
                    if (isDecoder) {
                        retValue = URLDecoder.decode(cookieList[i].getValue(), "UTF-8");
                    } else {
                        retValue = cookieList[i].getValue();
                    }
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }
        return retValue;
    }

    /**
     * 得到Cookie的值,使用自定义的编码类型进行解码
     * 
     * @param request
     * @param cookieName
     * @return
     */
    public static String getCookieValue(HttpServletRequest request, String cookieName, String encodeString) {
        Cookie[] cookieList = request.getCookies();
        if (cookieList == null || cookieName == null) {
            return null;
        }
        String retValue = null;
        try {
            for (int i = 0; i < cookieList.length; i++) {
                if (cookieList[i].getName().equals(cookieName)) {
                    //使用自定义的编码类型进行解码
                    retValue = URLDecoder.decode(cookieList[i].getValue(), encodeString);
                    break;
                }
            }
        } catch (UnsupportedEncodingException e) {
             e.printStackTrace();
        }
        return retValue;
    }

    /**
     * 设置Cookie的值 不设置生效时间默认浏览器关闭即失效,也不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue) {
        setCookie(request, response, cookieName, cookieValue, -1);
    }

    /**
     * 设置Cookie的值 在指定时间内生效,但不编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage) {
        setCookie(request, response, cookieName, cookieValue, cookieMaxage, false);
    }

    /**
     * 设置Cookie的值 不设置生效时间,但编码
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, boolean isEncode) {
        setCookie(request, response, cookieName, cookieValue, -1, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage, boolean isEncode) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, isEncode);
    }

    /**
     * 设置Cookie的值 在指定时间内生效, 编码参数(指定编码)
     */
    public static void setCookie(HttpServletRequest request, HttpServletResponse response, String cookieName,
            String cookieValue, int cookieMaxage, String encodeString) {
        doSetCookie(request, response, cookieName, cookieValue, cookieMaxage, encodeString);
    }

    /**
     * 删除Cookie带cookie域名，删除原理，把原来的cookie的Value用""
     */
    public static void deleteCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName) {
        doSetCookie(request, response, cookieName, "", -1, false);
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     * 
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName, String cookieValue, int cookieMaxage, boolean isEncode) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else if (isEncode) {
                //使用UTF-8进行编码
                cookieValue = URLEncoder.encode(cookieValue, "utf-8");
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                //设置Cookie的生存时间
                cookie.setMaxAge(cookieMaxage);
            if (null != request) {// 设置域名的cookie
                String domainName = getDomainName(request);
                System.out.println(domainName);
                if (!"localhost".equals(domainName)) {
                    cookie.setDomain(domainName);
                }
            }
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
             e.printStackTrace();
        }
    }

    /**
     * 设置Cookie的值，并使其在指定时间内生效
     * 
     * @param cookieMaxage cookie生效的最大秒数
     */
    private static final void doSetCookie(HttpServletRequest request, HttpServletResponse response,
            String cookieName, String cookieValue, int cookieMaxage, String encodeString) {
        try {
            if (cookieValue == null) {
                cookieValue = "";
            } else {
                cookieValue = URLEncoder.encode(cookieValue, encodeString);
            }
            Cookie cookie = new Cookie(cookieName, cookieValue);
            if (cookieMaxage > 0)
                cookie.setMaxAge(cookieMaxage);
            if (null != request) {// 设置域名的cookie
                String domainName = getDomainName(request);
                if (!"localhost".equals(domainName)) {
                    cookie.setDomain(domainName);
                }
            }
            cookie.setPath("/");
            response.addCookie(cookie);
        } catch (Exception e) {
             e.printStackTrace();
        }
    }

    /**
     * 得到cookie的域名
     */
    private static final String getDomainName(HttpServletRequest request) {
        String domainName = null;
        //获得请求的域名
        String serverName = request.getRequestURL().toString();
        if (serverName == null || serverName.equals("")) {
            domainName = "";
        } else {
            //全转为小写
            serverName = serverName.toLowerCase();
            //从第七个开始截取，过滤掉http://
            serverName = serverName.substring(7);
            //到后面的参数为止 比如 www.taobao.com/name=xxx
            final int end = serverName.indexOf("/");
            //把参数截取
            serverName = serverName.substring(0, end);
            //根据点来截取  
            final String[] domains = serverName.split("\.");
            int len = domains.length;
            if (len > 3) {
                // www.xxx.com.cn
                domainName = "." + domains[len - 3] + "." + domains[len - 2] + "." + domains[len - 1];
            } else if (len <= 3 && len > 1) {
                // xxx.com or xxx.cn
                domainName = "." + domains[len - 2] + "." + domains[len - 1];
            } else {
                domainName = serverName;
            }
        }
        //去掉端口号
        if (domainName != null && domainName.indexOf(":") > 0) {
            String[] ary = domainName.split("\:");
            domainName = ary[0];
        }
        return domainName;
    }

}