nodejs创建web服务器

const http = require("http");

http
  .createServer((req, res) => {
    res.write("fuck\n");
    res.writeHead(200, { "Content-Type": "text/html;charset=utf8" });
    res.end("fuck");
  })
  .listen(8080);

这样是返回不了内容的，不知道为啥子

const http = require("http");

http
  .createServer((req, res) => {
    res.writeHead(200, { "Content-Type": "text/html;charset=utf8" });
    res.write("fuck");
    res.end("fuck");
  })
  .listen(8080);

对比下，这种写法才行

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

http
  .createServer((req, res) => {
    let pathname = req.url;
    if (pathname === "/") {
      pathname = "/index.html";
    }
    if (pathname !== "/favicon.ico") {
      fs.readFile(`static${pathname}`, (err, data) => {
        if (err) throw err;
        res.write(data);
      });
    }
    res.end("fuck");
  })
  .listen(8080);

这样写是会报错的，先执行了end，再执行write

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

http
  .createServer((req, res) => {
    let pathname = req.url;
    if (pathname === "/") {
      pathname = "/index.html";
    }
    if (pathname !== "/favicon.ico") {
      fs.readFile(`static${pathname}`, (err, data) => {
        if (err) throw err;
        res.write(data);
        res.end("fuck");
      });
    }
  })
  .listen(8080);

这样写才对（现在是没有设置任何响应头，让浏览器自动的去做）

上面任然是很粗略的版本，很多异常的情况没有考虑进去

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

http
  .createServer((req, res) => {
    let pathname = req.url;
    if (pathname === "/") {
      pathname = "/index.html";
    }
    if (pathname !== "/favicon.ico") {
      pathname = url.parse(pathname).pathname;
      fs.readFile(`static${pathname}`, (err, data) => {
        if (err) {
          fs.readFile("static/404.html", (err, data) => {
            if (err) throw err;
            res.writeHead(404, { "Content-Type": "text/html;charset=utf8" });
            res.write(data);
            res.end();
          });
          return false;
        }
        res.writeHead(200, {
          "Content-Type": mime.getType(pathname) + ";charset=utf8"
        });
        res.write(data);
        res.end();
      });
    }
  })
  .listen(8080);

稍微完整的版本

const http = require("http");
const fs = require("fs");
const url = require("url");
const path = require("path");
const events = require("events");
const mime = require("./model/mime");

const EventEmitter = new events.EventEmitter();

http
  .createServer((req, res) => {
    let pathname = url.parse(req.url).pathname;
    if (req.url === "/") {
      pathname = "/index.html";
    }
    if (req.url !== "/favicon.ico") {
      fs.readFile(`static${pathname}`, (err, data) => {
        if (err) {
          fs.readFile("static/404.html", (err, data) => {
            if (err) throw err;
            res.end(data);
          });
        } else {
          const extname = path.extname(pathname);
          mime.getType(fs, EventEmitter, extname);
          EventEmitter.on("mime_type", mimeType => {
            res.writeHead(200, { "Content-Type": mimeType });
            res.end(data);
          });
        }
      });
    }
  })
  .listen(8080);

exports.getType = (fs, EventEmitter, extname) => {
  fs.readFile("./json/mime.json", (err, data) => {
    if (err) throw err;
    EventEmitter.emit("mime_type", JSON.parse(data.toString())[extname]);
  });
};

事件驱动的版本（还有一个回调函数的版本，很类似的写法）