NodeJs + Angular 2 CRUD JSON解析问题

const express = require('express');
const bodyParser = require('body-parser');

const app = express();
app.use(bodyParser.json());

// 处理POST请求，创建数据
app.post('/api/data', (req, res) => {
  const data = req.body;
  // 在这里处理数据的创建操作
  res.json({ message: 'Data created successfully' });
});

// 处理GET请求，获取数据
app.get('/api/data', (req, res) => {
  // 在这里处理数据的获取操作
  const data = { id: 1, name: 'John' };
  res.json(data);
});

// 处理PUT请求，更新数据
app.put('/api/data/:id', (req, res) => {
  const id = req.params.id;
  const data = req.body;
  // 在这里处理数据的更新操作
  res.json({ message: 'Data updated successfully' });
});

// 处理DELETE请求，删除数据
app.delete('/api/data/:id', (req, res) => {
  const id = req.params.id;
  // 在这里处理数据的删除操作
  res.json({ message: 'Data deleted successfully' });
});

app.listen(3000, () => {
  console.log('Server started on port 3000');
});

import { Component } from '@angular/core';
import { HttpClient } from '@angular/common/http';

@Component({
  selector: 'app-root',
  template: `
    <button (click)="createData()">Create Data</button>
    <button (click)="getData()">Get Data</button>
    <button (click)="updateData()">Update Data</button>
    <button (click)="deleteData()">Delete Data</button>
  `
})
export class AppComponent {
  constructor(private http: HttpClient) {}

  createData() {
    const data = { name: 'John' };
    this.http.post('/api/data', data).subscribe(response => {
      console.log(response);
    });
  }

  getData() {
    this.http.get('/api/data').subscribe(response => {
      console.log(response);
    });
  }

  updateData() {
    const id = 1;
    const data = { name: 'John Doe' };
    this.http.put(`/api/data/${id}`, data).subscribe(response => {
      console.log(response);
    });
  }

  deleteData() {
    const id = 1;
    this.http.delete(`/api/data/${id}`).subscribe(response => {
      console.log(response);
    });
  }
}