前端---------------：
  function send_JS_obj() {                   
        $.ajax({
            url: 'http://localhost:1007/send_JSobj_test?tag=test',
            type: 'POST',            
            data: JSON.stringify({ name: '张三', age: 20 }),
            success: function (response) {
                alert(response.received.name);
            }
        });
    }


后端------------------------：
const http_obj = require("http");//用于产生服务对象
const fs_obj = require("fs");//读写后台文件
const url_tran_obj = require("url");//解释URL

const server = http_obj.createServer(function (request, response) {
    //请求路径处理
    var req_str = decodeURI(request.url);
    var req_head;
    var POS = req_str.indexOf("?");
    if (POS == -1) { req_head = req_str; }
    else { req_head = req_str.substring(0, POS); }
    //设置查询对象
    var url_obj = url_tran_obj.parse(req_str, true);
    var Q_obj = url_obj.query;
    response.writeHead(200, {
        'Content-Type': 'application/json;charset=utf-8',
        'Access-Control-Allow-Origin': '*'
    });

    //%%%%%%%%%%%%%---------------begin your code

    if (req_head === '/send_JSobj_test') {
        console.log("接收到请求：", Q_obj["tag"]);
        let body = '';
        // 监听数据流
        request.on('data', chunk => {
            body += chunk;
        });
        // 数据接收完毕
        request.on('end', () => {            
            try {
                // 解析 JSON 字符串
                const jsonData = JSON.parse(body);
                console.log(jsonData.age);     
               
                response.end(JSON.stringify({ status: 'success', received: jsonData }));
            } catch (err) {
                response.end(JSON.stringify({ ERR: err.toString() }));
            }
        });
        return;
    }

    //%%%%%%%%%%%%%----------------end your code
});

server.listen(1007);
console.log("Server is running at port 1007...");