02_Node.js 基础模块（http，url）

一、http 模块

http.js

const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('http 模块。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node http.js，访问：127.0.0.1:3000/

二、url 模块

url.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    // 过滤掉 request.url == '/favicon.ico' 的情况，否则会打印两次结果
    if (request.url != '/favicon.ico') {
        console.log(url);
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node url.js，访问：127.0.0.1:3000/

{ parse: [Function: urlParse],
  resolve: [Function: urlResolve],
  resolveObject: [Function: urlResolveObject],
  format: [Function: urlFormat],
  URL:
   { [Function: URL]
     originFor: [Function],
     domainToASCII: [Function],
     domainToUnicode: [Function] },
  Url: [Function: Url] }

2.1 url 模块下 parse 函数

1、parse(获取地址信息)

parse.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    if (request.url != '/favicon.ico') {
        console.log(url.parse('http://www.baidu.com'));
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块下 parse 函数。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node parse.js，访问：127.0.0.1:3000/

Url {
  protocol: 'http:',
  slashes: true,
  auth: null,
  host: 'www.baidu.com',
  port: null,
  hostname: 'www.baidu.com',
  hash: null,
  search: null,
  query: null,
  pathname: '/',
  path: '/',
  href: 'http://www.baidu.com/' }

2、parse（传入参数）

parse2.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    if (request.url != '/favicon.ico') {
        console.log(url.parse('http://www.baidu.com?name=liu'));
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块下 parse 函数（传入参数）。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node parse2.js，访问：127.0.0.1:3000/

Url {
  protocol: 'http:',
  slashes: true,
  auth: null,
  host: 'www.baidu.com',
  port: null,
  hostname: 'www.baidu.com',
  hash: null,
  search: '?name=liu',
  query: 'name=liu',
  pathname: '/',
  path: '/?name=liu',
  href: 'http://www.baidu.com/?name=liu' }

3、parse（parse 扩展）

parse3.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    if (request.url != '/favicon.ico') {
        /*
        parse 方法可以传两个参数：
        第一个参数是地址。
        第二个参数是 true 的话表示把 get 传值转换成对象。
         */
        const result = url.parse(request.url, true);
        console.log(result);
        console.log(result.query.userName);
        console.log(result.query.userAge);
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块下 parse 函数（parse 扩展）。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node parse3.js，访问：127.0.0.1:3000/?userName=liu&userAge=24

Url {
  protocol: null,
  slashes: null,
  auth: null,
  host: null,
  port: null,
  hostname: null,
  hash: null,
  search: '?userName=liu&userAge=24',
  query: { userName: 'liu', userAge: '24' },
  pathname: '/',
  path: '/?userName=liu&userAge=24',
  href: '/?userName=liu&userAge=24' }
liu
24

2.2 url 模块下 format 函数

format: 逆向 parse。

format.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    if (request.url != '/favicon.ico') {
        console.log(url.format({
            protocol: null,
            slashes: null,
            auth: null,
            host: null,
            port: null,
            hostname: null,
            hash: null,
            search: '?userName=liu&userAge=24',
            query: {
                userName: 'liu',
                userAge: '24'
            },
            pathname: '/',
            path: '/?userName=liu&userAge=24',
            href: '/?userName=liu&userAge=24'
        }));
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块下 format 函数。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node format.js，访问：127.0.0.1:3000/

/?userName=liu&userAge=24

2.3 url 模块下 resolve 函数

resolve: 追加或替换地址。

resolve.js

const url = require('url');
const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;
const server = http.createServer((request, response) => {
    if (request.url != '/favicon.ico') {
        console.log(url.resolve('127.0.0.1:3000/?userName=liu&userAge=24', 'userName=zhao'));
    };
    response.statusCode = 200;
    response.setHeader('Content-Type', 'text/plain;charset=utf-8');
    response.end('url 模块下 resolve 函数。');
});
server.listen(port, hostname, () => {
    console.log(`服务器运行在 http://${hostname}:${port}`);
});

执行 node resolve.js，访问：127.0.0.1:3000/

127.0.0.1:3000/userName=zhao

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