Code

// 使用Node搭建一个简单的http服务器
// 加载http模块
let http = require('http')
let https = require('https')
var url = require("url");
// 调用http的createServer方法 创建一个服务器实例
let server = http.createServer()
// 监听request请求事件 设置请求处理函数
server.on('request', function (request, response) {
    if (request.method === 'OPTIONS') {
        response.setHeader('Access-Control-Allow-Origin', '*')
        response.setHeader('Access-Control-Allow-Headers', '*')
        response.setHeader('Access-Control-Allow-Methods', '*')
        response.write('')
    } else {
        const data = url.parse(request.url)
        // http://127.0.0.1:9988/source?path=https://mdn.github.io/learning-area/html/multimedia-and-embedding/video-and-audio-content/rabbit320.mp4
        if (data.pathname === '/source') {
            const path = new URLSearchParams(data.query).get('path')
            const options = {
                method: "GET",
                responseType: 'blob',
                headers: { // "Content-Type": "application/json"
                }
            };
            const clientRequest = https.request(path, options, (incomingMessage) => {
                // 设置headers
                // const keys = Object.keys(incomingMessage.headers)
                // for (let n of keys) {
                //     response.setHeader(n, incomingMessage.headers[n])
                // }
                response.setHeader('Access-Control-Allow-Origin', '*')
                response.setHeader('Access-Control-Allow-Headers', '*')
                response.setHeader('Access-Control-Allow-Methods', '*')
                console.log(`状态码: ${
                    incomingMessage.statusCode
                }`);
                incomingMessage.on("data", (d) => { // process.stdout.write(d);
                    console.log(d.length)
                    response.write(d)
                });
                incomingMessage.on('end', () => {
                    response.end()
                })
                response.writeHead(incomingMessage.statusCode, incomingMessage.headers);
            });
            // POST
            request.on('data', function (chunk) {
                console.log('in request length:', chunk.length);
                clientRequest.write(chunk, 'binary');
            });
            request.on('end', function () {
                console.log('request end')
                // 向proxy发送求情，这里end方法必须被调用才能发起代理请求
                // 所有的客户端请求都需要通过end来发起
                clientRequest.end();
            });
            clientRequest.on("error", (error) => {
                console.error(error);
            });
            clientRequest.on('close', (val) => {
                console.log('close')
            })
            // POST 请求会使用到这个
            // clientRequest.write(JSON.stringify(data));
        }
    }
})
// 绑定端口号 启动服务
server.listen(9988, function () {
    console.log('已经开启您的http服务器')
    console.log('http://127.0.0.1:9988')
})

Use

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document Demo</title>
  </head>
  <body>
    <button id="download">Download</button>
    <script>
      const download = document.querySelector("#download");
      download.addEventListener("click", () => {
        // 改变状态
        download.disabled = true;
        fetch();
      });
      function fetch() {
        // 1. 创建一个 new XMLHttpRequest 对象
        let xhr = new XMLHttpRequest();
        xhr.responseType = "blob";
        // 2. 配置它：从 URL /article/.../load GET-request
        xhr.open(
          "GET",
          "http://127.0.0.1:9988/source?path=https://mdn.github.io/learning-area/html/multimedia-and-embedding/video-and-audio-content/rabbit320.mp4"
        );
        xhr.setRequestHeader("haha", "haha");
        // 3. 通过网络发送请求
        xhr.send();
        // 4. 当接收到响应后，将调用此函数
        xhr.onload = function () {
          if (xhr.status != 200) {
            // 分析响应的 HTTP 状态
            console.log(`Error ${xhr.status}: ${xhr.statusText}`); // 例如 404: Not Found
          } else {
            // 显示结果
            // console.log(`Done, got ${xhr.response.length} bytes`); // response 是服务器响应
            console.log(`Done, got ${xhr.response.size} bytes`, xhr.response);
            const download = document.createElement("a");
            // 创建blob对象，将二进制数据封装为BLOB对象
            // const blob = new Blob([res], {
            //   type: type
            // })
            const blob = xhr.response;
            // 兼容webkix浏览器，处理webkit浏览器中herf自动添加blob前缀，默认在浏览器打开而不是下载
            const URL = window.URL || window.webkitURL;
            // 根据blob对象创建URL 对象，生成本地URL
            const herf = URL.createObjectURL(blob);
            download.href = herf;
            // 下载链接
            download.download = "123";
            download.click();
            // 改变状态
            download.disabled = false;
            // 在内存中移除URL 对象
            window.URL.revokeObjectURL(herf);
          }
        };
        xhr.onprogress = function (event) {
          if (event.lengthComputable) {
            console.log(`Received ${event.loaded} of ${event.total} bytes`);
          } else {
            console.log(
              `Received ${event.loaded} bytes`,
              "没有 Content-Length"
            );
          }
        };
        xhr.onerror = function () {
          console.log("Request failed");
        };
      }
    </script>
  </body>
</html>

写给你我的知识

node做文件代理中转

Code

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