课程名称： 新版 Node.js+Express+Koa2 开发Web Server博客

课程章节： 8-5 stream演示（2）

课程讲师： 双越

课程内容：

文件io stream：

当前目录:

• 创建 data.txt ，要拷贝的文件，需要有内容
• 创建 data-bak.txt，拷贝后数据存放文件

// 复制文件
const fs = require("fs");
const path = require("path");

const fileName1 = path.resolve(__dirname, "data.txt");
const fileName2 = path.resolve(__dirname, "data-bak.txt");

// 读取文件的流
const readStream = fs.createReadStream(fileName1);
// 写入文件的流
const writeStream = fs.createWriteStream(fileName2);

readStream.pipe(writeStream);

// 监听流读取的内容
readStream.on("data", (chunk) => {
  console.log(chunk.toString());
});

// 监听了流读取完成
readStream.on("end", () => {
  console.log("copy done");
});

结合文件io和网络io的strmea：

const http = require("http");
const fs = require("fs");
const path = require("path");

const fileName1 = path.resolve(__dirname, "data.txt");

const server = http.createServer((req, res) => {
  if (req.method === "GET") {
    // 读取文件的流
    const readStream = fs.createReadStream(fileName1);
    readStream.pipe(res);
  }
});
server.listen(8004);

课程收获：

1. 了解文件和网络的io怎么操作