Angular客户端收到来自带有Expressjs服务器的POST请求的OK错误

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

app.use(bodyParser.json());

app.post('/your-endpoint', (req, res) => {
  // 处理请求数据
  console.log(req.body);

  // 发送响应
  res.status(200).send('OK');
});

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

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

constructor(private http: HttpClient) {}

sendPostRequest() {
  const data = { key: 'value' };

  this.http.post('http://localhost:3000/your-endpoint', data).subscribe(
    (response) => {
      console.log('POST请求成功:', response);
    },
    (error) => {
      console.error('POST请求错误:', error);
    }
  );
}

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

app.use(cors());
app.use(bodyParser.json());

// 其他路由和中间件