单点登录是否新版才能生效，我使用的是6.7.12的。照着例子做报错。信息如下：
T:\Studio_Projects\demo\modules\web\src\com\company\demo\web\login\ExtAppLoginWindow.java:78: error: cannot find symbol
Connection connection = app.getConnection();
^ symbol: variable app location: class ExtAppLoginWindow
T:\Studio_Projects\demo\modules\web\src\com\company\demo\web\login\ExtAppLoginWindow.java:81: error: cannot find symbol
connection.login(new ExternalUserCredentials(user.getLogin(), defaultLocale));
^ symbol: class ExternalUserCredentials
location: class ExtAppLoginWindow
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.