不多說直接上代碼！

const http = require('http');
const url = require('url');
const querystring = require('querystring');


http.createServer(function(oreq, ores) {
    console.log("服務已開啟");
    if (oreq) {
        if (oreq.url !== '/favicon.ico') {
            let content = '',
                postData = '';
            // 封裝獲取參數的方法
            function getParmas(oUrl) {
                let oQuery = (typeof oUrl === "object") ? oUrl : url.parse(oUrl, true).query,
                    data = {};
                for (item in oQuery) {
                    if (item !== 'hostname') {
                        if (item !== 'path') {
                            data[item] = oQuery[item];
                        }
                    }
                }
                return querystring.stringify(data);
            };
            // 封裝發起http請求的方法
            function httpRequest(options, ores) {
                let datas = "";
                return http.request(options, function(res) {
                    res.setEncoding('utf8');
                    res.on('data', function(chunk) {
                        // 返回數據
                        datas += chunk;
                    });
                    res.on('end', function() {
                        ores.writeHead(200, {
                            "Content-Type": "application/json; charset = UTF-8",
                            "Access-Control-Allow-Origin": "*"
                        });
                        ores.end(datas);
                    })
                })
            };
            // 數據塊接收中
            console.log(oreq.method.toUpperCase());
            if (oreq.method.toUpperCase() === "POST") {
                console.log("進入POST");
                oreq.on("data", function(postDataChunk) {
                    postData += postDataChunk;
                });
                // 數據接收完畢，執行回調函數
                oreq.on("end", function() {
                    console.log("接收完畢")
                    console.log(postData);
                        // 配置options
                    let oData = JSON.parse(postData);
                    
                    postData = getParmas(oData);
                    
                    let options = {
                        hostname: oData.hostname,
                        port: '80',
                        path: oData.path,
                        method: "POST"
                    };
                    // 發送請求
                    let req = httpRequest(options, ores);
                    req.on('error', function(e) {
                        console.log('problem with request: ' + e.message);
                    });
                    req.write(postData); //發送請求數據
                    req.end();
                });

            } else {
                let queryObj = url.parse(oreq.url, true).query;
                content = getParmas(oreq.url);
                let options = {
                    hostname: queryObj.hostname,
                    port: '80',
                    path: queryObj.path + content,
                    method: "GET"
                };
                // 發送請求
                let req = httpRequest(options, ores);
                req.on('error', function(e) {
                    console.log('problem with request: ' + e.message);
                });
                req.end();
            }
        }
    }
}).listen(8080, '127.0.0.1');