对 https://stackoverflow.com/jobs/feed 的 http get 请求因 CORS 失败

如何解决对 https://stackoverflow.com/jobs/feed 的 http get 请求因 CORS 失败

我想阅读 StackOverflow 作业 RSS 提要，我也尝试添加“Access-Control-Allow-Headers”和代理实现，但它出错了。请帮我实现这个[已解决，请参阅下面的答案]

API 网址：https://stackoverflow.com/jobs/feed

  private proxyPrefix = '/api';
  private hostName = 'stackoverflow.com';
  private location='sydney'
  private query = `location=${this.location}`;
  private path = 'jobs/Feed';
  
  private stackOverFlowJobsRSSFeedUrl = `${this.hostName}/${this.path}?${this.query}`;
  constructor(private http: HttpClient) { }

  private getData$(url: string): Observable<any> {
    const requestOptions = { headers: new HttpHeaders({ 'Access-Control-Allow-Headers': '*' }) };
    return this.http.get<any>(url,requestOptions);
  }
    
  private get stackOverflowJobs$(): Observable<any> {
    const proxyURL = `${this.proxyPrefix}/${this.path}?${this.query}`;
    return fromFetch(proxyURL,{
      selector: response => response.json()
    });
  }
    
  ngOnInit(): void {

    // http get
    this.getData$(this.stackOverFlowJobsRSSFeedUrl)
      .subscribe((x) => {
        console.log(x);
      });
    
    // rxJs fetch using proxy
    this.stackOverflowJobs$.subscribe({
      next: result => console.log('jobs:',result),complete: () => console.log('done')
    });

  }

proxy.config

{
  "/api/jobs": {
     "target":  {
       "host": "https://stackoverflow.com","protocol": "https:","port": 443
     },"secure": false,"changeOrigin": true,"logLevel": "info"
  }
}

错误

[HPM] Error occurred while trying to proxy request /api/jobs/Feed?location=sydney from localhost:4200 to https://stackoverflow.com (ENOTFOUND) (https://nodejs.org/api/errors.html#errors_common_system_errors)

解决方法

您确定 SO 服务器端允许使用 CORS 吗？尝试从 SO 和开发工具中的另一个域控制台发送此信息，您将仅收到来自 SO 的响应。 一种选择是设置一些服务器并将其用作中间件，那么CORS问题将不相关

fetch('https://stackoverflow.com/jobs/feed')
  .then(function(response) {
    return response.text();
  }).then(function(data) {
    console.log(data); // this will be a string
});

,

{
  "/proxy/*": {
  "target": "https://stackoverflow.com","secure": false,"changeOrigin": true,"logLevel": "debug","pathRewrite": {"^/proxy" : ""}
  }
}

这个代理配置解决了我的问题:)

StackOverflow 参考：Angular-CLI proxy to backend doesn't work