[js]nodejs初探http/url/fs模块

2023-07-18 18:25:52

难怪我没学会, 因为我的套路有问题. 错误点, 1,大而全 2,不注重思路

学习要领: 

1, 小而精

2, 重思路(总结)

nodejs特点:

    1.node提供了js的运行环境, 一般将node运行在服务端, 丰富了各种模块,jsplus

    2.大量的工具库

    3.事件驱动&异步IO,谷歌v8引擎

全局js对象是windows,而node环境下全局js对象是global

express 基于nodejs的web框架: Fast, unopinionated, minimalist web framework for Node.js

node命令参数

参考

npm install module-name -save 自动把模块和版本号添加到dependencies部分,新版本的node可以省略这个参数

npm install module-name -save-dve 自动把模块和版本号添加到devdependencies部分

-S, --save: Package will appear in your dependencies.新版本node的可以省略

-D, --save-dev: Package will appear in your devDependencies.

-O, --save-optional: Package will appear in your optionalDependencies.

还有一个设置代理, 公司里会用到(因为有网络限制)

下载长期支持版

    https://nodejs.org/en/

npm install -g cnpm --registry=https://registry.npm.taobao.org

创建文件模板:

<template>

    <div></div>

</template>

<script>

    export default {

        data() {

            return {}

        },

        methods: {},

        computed: {},

        componets: {}

    }

</script>

<style scoped>

</style>

解决webstorm卡顿问题

cd s1

npm init -y  # 默认是ISC协议, 一般是MIT协议,*可更改,永久免费

npm install vue axios bootstrap

- repl环境: 即交互环境

read-eval-print loop '读取--求值--输出' 循环

思路:

1.创建服务器,访问

2,区分path和query

3,返回指定html, fs模块

4,返回任意html

5.根据后缀设置content-type

// 思路: 接收请求 -- 获取后缀 -- 设置content-type -- 响应

url里的path和query的区别

url里的path和query-http和url模块

var http = require("http"),

    url = require("url"),

    fs = require("fs");

s1 = http.createServer(function (req, res) {

    // res.write("<h1>hello yifei</h1>");

    // res.end();

    var urlObj = url.parse(req.url, true),

        pathname = urlObj['pathname'], //path

        query = urlObj['query']; //?后面的参数 {}类型

    console.log(pathname);

    console.log(query);

    res.end();//终结请求

});

s1.listen(1234, function () {

    console.log("http://127.0.0.1:1234/getdata/?name=maotai&age=22");

});

结果

fs模块: 返回网页

index.html

<!DOCTYPE html>

<html lang="en">

<head>

    <meta charset="UTF-8">

    <title>test</title>

    <link rel="stylesheet" href="css/base.css">

</head>

<body>

<h1>用户登录</h1>

<form action="/add.html" method="get">

    <p>用户: <input type="text" name="username"></p>

    <p>密码: <input type="text" name="password"></p>

    <p><input type="submit"></p>

</form>

</body>

</html>

css/base.css

body{

    background-color: #0086b3;

}

node代码

var http = require('http'),

    url = require('url'),

    fs = require('fs');

s1 = http.createServer(function (req, res) {

    var urlObj = url.parse(req.url, true),

        pathname = urlObj['pathname'],

        query = urlObj['query'];

    console.log(pathname, query);

    if (pathname === "/index.html") {

        var con = fs.readFileSync("./index.html"); //读取html,返回

        res.end(con);

        return;

    }

    if (pathname === "/css/base.css") { //index.html里会调用css

        con = fs.readFileSync("./css/base.css","utf-8");

        res.end(con);

        return;

    }

});

s1.listen("1234", function () {

    console.log("http://127.0.0.1:1234/index.html");

});

根据pathname返回不通的url

最简陋的实现(如果html不存在会报错)

var http = require("http"),

    url = require("url"),

    fs = require("fs");

s1 = http.createServer(function (req, res) {

    var urlObj = url.parse(req.url),

        pathname = urlObj['pathname'],

        query = urlObj['query'];

    pathname = "." + pathname;

    var con = fs.readFileSync(pathname); //根据pathname返回不同的url

    res.end(con);

    return; //代表终结

});

s1.listen(1234, function () {

    console.log("http://127.0.0.1:1234/index.html")

});

处理错误

var http = require("http"),

    url = require("url"),

    fs = require("fs");

s1 = http.createServer(function (req, res) {

    var urlObj = url.parse(req.url),

        pathname = urlObj['pathname'],

        query = urlObj['query'];

    try {

        var con = fs.readFileSync('.'+pathname);

        res.end(con);

    } catch (e) {

        res.end("request file is not fonund!")

    }

    return;

});

s1.listen(1234, function () {

    console.log("http://127.0.0.1:1234/index.html")

});

处理mime

每一种资源文件都有自己的标识类型. 浏览器按照提供的MIME(content-type)类型渲染页面

什么是MIME,及conetent-type

即不通类型不同的显示,如html css

谷歌浏览器会智能处理一些类型.

// 思路: 接收请求 -- 获取后缀 -- 设置content-type -- 响应

var http = require('http'),

    url = require('url'),

    fs = require('fs');

s1 = http.createServer(function (req, res) {

    var urlObj = url.parse(req.url),

        pathname = urlObj['pathname'],

        query = urlObj['query'];

    var reg = /\.(HTML|CSS|JS|JSON|TXT|ICO)/i;

    var suffixMIME = 'text/plain';

    if (reg.test(pathname)) {

        var suffix = reg.exec(pathname)[1].toUpperCase();

        switch (suffix) {

            case "HTML":

                suffixMIME = 'text/html';

                break;

            case "JS":

                suffixMIME = 'text/javascript';

                break;

            case "CSS":

                suffixMIME = 'text/css';

                break;

            case "JSON":

                suffixMIME = 'application/json';

                break;

            case "ICO":

                suffixMIME = 'application/octet-stream';

                break;

        }

    }

    try {

        con = fs.readFileSync('.' + pathname);

        res.writeHead(200, {'content-type': suffixMIME + ';charset=utf-8'});

        res.end(con);

    } catch (e) {

        res.writeHead(404, {'content-type': 'text/plain;charset=utf-8'});

        res.end("file not found")

    }

});

s1.listen(1234, function () {

    console.log("http://127.0.0.1:1234/index.html");

});

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