通过redis使双系统session共享的解决思路

1.背景条件

1. 两个系统A和B
2. A为主,B为次
3. 登录入口是A

2.共享登录逻辑流程(不使用session)

1. A登录时,生成一个随机码token,例如UUID
2. 将token做为key,userId做为value,存入redis,设置过期时间
3. 将token存入cookie,设置过期时间,设置domain
4. A,B系统通过cookie获取token,然后从redis获取userId
5. 注销时,删除redis中的token,删除cookie

3.session共享逻辑流程(使用session)

1. A登录时,将信息存入session,然后生成一个随机码token,例如UUID
2. 将token做为key,session做为value,存入redis,设置过期时间
3. 将token存入cookie,设置过期时间,设置domain
4. A,B系统通过cookie获取token,然后从redis获取session
5. 判断从redis获取的session和原来的session是否一致,若不一致,则需要覆盖原来的session(主要为了防止重复覆盖和session不一致)
6. 注销时,删除redis中的token,删除cookie

代码举例(第二种)

1. A系统 login:

// 系统session
session.set("userId","firetw");
...

// session信息存入map
Map<String,String> sessionMap = new HashMap<String, String>();
sessionMap.put("userId","firetw");
...

HttpServletResponse response = ServletActionContext.getResponse();
// 随机token
String token=UUID.randomUUID().toString().toLowerCase().replace("-", "");
// userId存入redis
RedisUtil.setString("token_"+token, bean.getUserId(), pcExpire);
// sessionMap存入redis
RedisUtil.setMap("session_"+token, sessionMap, pcExpire);

//token存入cookie
Cookie cookie = new Cookie("wx_token", token);
cookie.setPath("/");
cookie.setDomain(".zpfdomain.com");
cookie.setMaxAge(pcExpire);
response.addCookie(cookie);

1. A,B系统公用sessionUtils

/**
 * 把redis中的sessionMap复制到appSession中
 * @param request
 * @param appSession
 */
public static void initSession(HttpServletRequest request, AppSession appSession) {
    // 获取redis的session
    Map<String, String> sessionMap = SessionUtils.getSessionMap(request);
    // 如果redis没有找到session,表明已是登出状态,将老系统的appSession置为空
    if (MapUtils.isEmpty(sessionMap)) {
        appSession.set(PageParamConstant.LOGIN_ID, "");
    } else {
        // 避免重复赋值
        if (!sessionMap.get(PageParamConstant.LOGIN_ID).equals(appSession.getStringValue(PageParamConstant.LOGIN_ID))) {
            // 将sessionMap复制到appSession
            appSession.set(PageParamConstant.LOGIN_ID, sessionMap.get(PageParamConstant.LOGIN_ID));// 登录用户
            appSession.set(PageParamConstant.PASSWORD,DesCodeUtil.encrypt(sessionMap.get(PageParamConstant.PASSWORD)));//登录密码
        }
    }
}


/**
 * 从redis中获取session
 * @param request
 * @return
 */
@SuppressWarnings("unchecked")
public static Map<String, String> getSessionMap(HttpServletRequest request) {
    String token = getToken(request);
    Map<String, String> sessionMap = RedisUtil.getMap("session_"+token);

    return sessionMap;
}



/**
 * 获取cookie中的token
 * @param request
 * @return
 */
public static String getToken(HttpServletRequest request) {
    String token = "";
    Cookie c = CookieTool.getCookieByName(request, "wx_token");
    if (c != null) {
        token = c.getValue();
    }

    return token;
}


/**
 * 根据名字获取cookie（接口方法）
 * 
 * @author 
 * @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（非接口方法）
 * 
 * @author 
 * @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;
}

1. 注销 logout

Cookie[] cookies = httpServletRequest.getCookies();
String wx_token="";
for (Cookie cookie : cookies) {
    if("wx_token".equals(cookie.getName())){
        wx_token = cookie.getValue();
        RedisUtil.removeKey("token_"+wx_token);
        RedisUtil.removeKey("session_"+wx_token);
        // 销毁cookie
        HttpServletResponse response = ServletActionContext.getResponse();
        cookie.setMaxAge(0);
        // 必须要设置,否组浏览器不会删除cookie
        cookie.setPath("/");
        cookie.setDomain(".zpfdomain.com");
        response.addCookie(cookie);
    }
}