我有一个移动应用程序,该应用程序可以根据用户所执行的操作顺序调用不同的API。例如,
1) get app specific details go to url https://config.url with GET
2) user login, go to url https://login.url with POST
3)perform step 1 at url https://step.url with POST
4) perform step 2 at url https://step.url with POST
5) get file at url http://file.url with GET
步骤(1)和(2)必须成功完成,然后才能执行其余步骤。如果强制性步骤失败,如何停止当前序列,而又不影响运行中的其他顺序任务?