SpringMVC,redirect 重定向的问题

老系统是 SpringMVC 集成 shiro 做的权限认证。现在要改为集团统一认证。
流程为：访问域名->跳转到登录接口->判断是否登录->跳转集团登录页->登录成功后 return 回来我们的系统首页。
遇到的问题：集团登录页是个 https 的链接。登录的 Controller 最后==return "redirect:" + targetUrl;==。但是 targetUrl 改为http就可以正常跳转，如果是https虽然不影响使用，但是会一直重复调用 login 的接口。
尝试使用 http://www.baidu.com 和 https://www.baidu.com 也是一样的情况。现在不清楚问题到底是shiro引发的？还是SpringMVC的redirect引发的。奇怪的是退出的接口不管是 http 还是 https 都是正常的。
相关代码放到下面了，有懂得大手子麻烦帮忙看下给点建议！！！

// 登录接口
@RequestMapping(value = "${adminPath}/login", method = RequestMethod.GET)
    public String e2Login(HttpServletRequest request,
                          HttpServletResponse response, Model model) {
        User user = UserUtils.getUser();
        // 如果已经登录，则跳转到管理首页
        if (user != null) {
            if (user.getId() != null && user.getId() > -1) {
                return "redirect:" + Global.getAdminPath();
            } else {
                return "error/403";
            }
        } else {
            String e2state = java.util.UUID.randomUUID().toString();
            X3.Service.X3App x3app = new X3.Service.X3App(request, response);
            x3app.SetCookie("e2state", e2state);
            String targetUrl = Global.getConfig("e2.LoginUrl") + "?client_id="
                    + Global.getConfig("e2.ClientId")
                    + "&returnUrl="
                    + Global.getConfig("e2.ReturnUrl");
            model.addAttribute("targetUrl", targetUrl);
            return "redirect:" + targetUrl;
        }
    }
    

// 退出接口
   @RequestMapping(value = "/logout")
    public String adminLogout(HttpServletRequest request,
                              HttpServletResponse response) {
        logger.info("======================= logout====================");
        X3App app = new X3App(request, null);
        Subject subject = SecurityUtils.getSubject();
        subject.getSession().removeAttribute(app.GetCookie("e2state"));
        String returnUrl = WebUtilX.UrlEncode(Global.getConfig("u2.Callback"));

        String logoutUrl = Global.getConfig("u2.LogoutUrl") + "?ClientId="
                 + Global.getConfig("u2.ClientId") + "&ReturnUrl=" + returnUrl;

        String returnUrl = WebUtilX.UrlEncode(Global.getConfig("e2.ReturnUrl"));
        String logoutUrl = Global.getConfig("e2.LogoutUrl") + "?ClientId="
                + Global.getConfig("e2.ClientId") + "&ReturnUrl=" + returnUrl;
        subject.logout();
        return "redirect:" + logoutUrl;
    }

// shiro 过滤器
 <bean id="shiroFilter" class="org.apache.shiro.spring.web.ShiroFilterFactoryBean">
        <property name="securityManager" ref="securityManager"/>
        <property name="loginUrl" value="${adminPath}/login"/>
        <property name="successUrl" value="/index"/>
        <property name="filters">
            <map>
                <entry key="authc" value-ref="formAuthenticationFilter"/>
                <entry key="oauth2Authc" value-ref="oAuth2AuthenticationFilter"/>
            </map>
        </property>
        <property name="filterChainDefinitions">
            <value>
                /report/postContent/** = anon
                /studentlist/** = anon
                /courseInfo/** = anon
                /studyInfo/** = anon
                /studyservice/** = anon
                /newwork/** = anon
                /workflow/** = anon
                /static/** = anon
                /userfiles/** = anon
                /servlet/** = anon
                /app/**=anon
                /demo/**=anon
                ${adminPath}/login = authc
                /e2/callback = oauth2Authc
                /admin = anon
                ${adminPath}/logout = authc
                /** = user
            </value>
        </property>
    </bean>