从nodejs获取json数据到Angular 6

// server.js
const express = require('express');
const app = express();
const port = 3000;

app.get('/api/data', (req, res) => {
  res.json({ message: 'Hello from Node.js server!' });
});

app.listen(port, () => {
  console.log(`Server running at http://localhost:${port}`);
});

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpClientModule } from '@angular/common/http';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

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

@Injectable({
  providedIn: 'root'
})
export class DataService {

  private apiUrl = 'http://localhost:3000/api/data';

  constructor(private http: HttpClient) { }

  getData(): Observable<any> {
    return this.http.get<any>(this.apiUrl);
  }
}

import { Component, OnInit } from '@angular/core';
import { DataService } from './data.service';

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

  constructor(private dataService: DataService) {}

  ngOnInit() {
    this.dataService.getData().subscribe(data => {
      this.data = data;
      console.log(this.data);
    }, error => {
      console.error('Error fetching data', error);
    });
  }
}

<h1>Data from Node.js Server</h1>
<p>{{ data | json }}</p>