angular5到n级的JSON到侧边菜单生成

import { HttpClientModule } from '@angular/common/http';

@NgModule({
  imports: [
    HttpClientModule
  ],
  ...
})

import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';
import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class MenuService {
  private jsonUrl = 'assets/menu.json';

  constructor(private http: HttpClient) { }

  getMenuData(): Observable<any> {
    return this.http.get<any>(this.jsonUrl);
  }
}

import { Component, OnInit } from '@angular/core';
import { MenuService } from '../menu.service';

@Component({
  selector: 'app-menu',
  templateUrl: './menu.component.html',
  styleUrls: ['./menu.component.css']
})
export class MenuComponent implements OnInit {
  menuData: any[];

  constructor(private menuService: MenuService) { }

  ngOnInit(): void {
    this.getMenuData();
  }

  getMenuData(): void {
    this.menuService.getMenuData()
      .subscribe(data => {
        this.menuData = data;
      });
  }
}

<ul>
  <li *ngFor="let item of menuData">
    <a [href]="item.url">{{ item.name }}</a>
  </li>
</ul>