Angular 5的拦截器:发出第二个请求并返回其结果，而不是第一个请求的结果

import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpEvent } from '@angular/common/http';
import { Observable } from 'rxjs';
import { mergeMap } from 'rxjs/operators';
import { HttpClient } from '@angular/common/http';

@Injectable()
export class SecondRequestInterceptor implements HttpInterceptor {
  constructor(private http: HttpClient) {}

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(
      mergeMap((event: HttpEvent<any>) => {
        if (event instanceof HttpResponse && event.status === 200) {
          // 处理第一个请求的结果
          const firstResponse = event.body;

          // 创建第二个请求对象
          const secondRequest = new HttpRequest('GET', 'https://example.com/second-request');

          // 发送第二个请求
          return this.http.request(secondRequest).pipe(
            mergeMap((secondEvent: HttpEvent<any>) => {
              if (secondEvent instanceof HttpResponse && secondEvent.status === 200) {
                // 处理第二个请求的结果
                const secondResponse = secondEvent.body;

                // 返回第二个请求的结果
                return of(secondResponse);
              } else {
                // 处理第二个请求失败的情况
                return throwError('Second request failed');
              }
            })
          );
        } else {
          // 处理第一个请求失败的情况
          return throwError('First request failed');
        }
      })
    );
  }
}