js返回json后台怎么接收

// 前端代码
const data = {
  name: 'John',
  age: 30
};

fetch('/api/data', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json'
  },
  body: JSON.stringify(data)
})
.then(response => response.json())
.then(data => console.log('Success:', data))
.catch((error) => console.error('Error:', error));

const express = require('express');
const app = express();

app.use(express.json()); // 用于解析JSON格式的请求体

app.post('/api/data', (req, res) => {
  const data = req.body;
  console.log(data); // 输出接收到的JSON数据
  res.json({ message: 'Data received' });
});

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

from flask import Flask, request, jsonify

app = Flask(__name__)

@app.route('/api/data', methods=['POST'])
def receive_data():
    data = request.get_json()
    print(data)  # 输出接收到的JSON数据
    return jsonify({'message': 'Data received'})

if __name__ == '__main__':
    app.run(port=3000)

import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/api")
public class DataController {

    @PostMapping("/data")
    public String receiveData(@RequestBody Map<String, Object> data) {
        System.out.println(data); // 输出接收到的JSON数据
        return "{\"message\": \"Data received\"}";
    }
}