单点登录需要在需要进入的子系统B中添加一个类，用于接收A系统传过来的参数；

@Action(value = "outerLogin", results = {

            @Result(name = "redirect", type = "redirect", location = "${innerUrl}")

    })

    public String outerLogin() {

        try {

            if (userName != null && userName.trim().length() > 0) {

                TPolicemen policemen = policeMenService.getPolicemenByJh(userName);

                if (policemen != null) {

                    //获取当前登录用户所在IP

                    String ipStr = CommonService.getIpAddr(this.request);

                    policemen.setIpStr(ipStr);

                    this.session.put(AuthInterceptor.USER_SESSION_KEY, policemen);

                    response.setHeader("P3P", "CP=CAO PSA OUR");

                    innerUrl = outerUrl;

                    return "redirect";

                } else {

                    loginStr = "用户名或者密码错误";

                }

            }

        } catch (Exception e) {

            this.clientMessage(e.getMessage());

        }

        return "login";

    }

A系统中点击某个链接，url格式形如：

防止iframe跨域访问cookie/session丢失的解决办法是，在保存session后添加一段代码：即

response.setHeader("P3P", "CP=CAO PSA OUR");