TypeError：无法读取SafeSubscriber上未定义的属性“ next”。_next

Question

我正在使用以下代码来订阅我的连接API，但是我收到以下错误。 每5秒调用一次使用的getconnection（）函数。

getConnections() {
this.httpClient.get('/api/api_server.json').subscribe(
  (apipath: any) => {
    this.apiDataService.connectionStatusService = setInterval(() => {
                this.httpClient.get(apipath['server']+'/api/connection').subscribe((res: any[]) => {
        console.log(res);
        var data: any = res;
        this.observers.connectionAsObserver.next(data[0]);
      });
    }, 5000);
  });

}

---

数据包含

[{ “ current_timestamp”：“ 2020-09-13T23：07：28”， “ machine_name”：“ raiod”， “状态”：“确定” }]

ERROR TypeError: Cannot read property 'next' of undefined
at SafeSubscriber._next (app-data.service.ts:849)
at SafeSubscriber.__tryOrUnsub (Subscriber.js:185)
at SafeSubscriber.next (Subscriber.js:124)
at Subscriber._next (Subscriber.js:72)
at Subscriber.next (Subscriber.js:49)