Node.js学习——封装Express的app.get()、app.post()方法

封装一个Express的app.get()

新建一个项目文件，新建/modules/routers.js

const url = require('url');
let methods = {};

let app = function(req,res){
    let pathName = url.parse(req.url).pathname;
    if(methods[pathName]){
        methods[pathName](req,res)
    }else{
        res.writeHead(404, {
            "Content-Type": "text/html;charset=UTF-8"
        });
        res.end('页面不存在');
    }
}

app.get = function(pathName, cd){
    methods[pathName] = cd;
}

module.exports = app;

使用上述封装的方法，新建/app.js

const http = require('http');
const app = require('./modules/routers')

http.createServer(app).listen(3000);

app.get('/login',(req,res)=>{
    res.writeHead(200, {
        "Content-Type": "text/html;charset=UTF-8"
    });
    res.end('访问登录界面');
})
app.get('/news',(req,res)=>{
    res.writeHead(200, {
        "Content-Type": "text/html;charset=UTF-8"
    });
    res.end('访问新闻界面');
})
app.get('/register',(req,res)=>{
    res.writeHead(200, {
        "Content-Type": "text/html;charset=UTF-8"
    });
    res.end('访问注册界面');
})

此时浏览器地址栏中输入
http://127.0.0.1:3000/login
页面内容为：访问登录界面
输入
http://127.0.0.1:3000/xxx
页面内容为：页面不存在

封装POST方法

app.js中

const http = require('http');
const path = require('path');
const app = require('./modules/routers')

const ejs = require('ejs');

http.createServer(app).listen(3000);

app.get('/login',(req,res)=>{
    ejs.renderFile(path.join(__dirname,'./views/form.ejs'),(err,data)=>{
        res.send(data);
    })
})
app.post('/doLogin',(req,res)=>{
    res.send(req.body);
})
app.get('/news',(req,res)=>{
    res.send();
})
app.get('/register',(req,res)=>{
    res.send('访问注册界面');
})

/modules/router.js

const fs = require('fs');
const path = require('path');
const url = require('url');
// 封装 res.writeHead和res.end
function changeRes(req, res) {
    res['send'] = (str) => {
        res.writeHead(200, {
            "Content-Type": "text/html;charset=UTF-8"
        });
        res.end(str);
    }
}

let server = () => {
    let methods = {
        _get: {},
        _post: {},
    };
    let app = function (req, res) {
        changeRes(req, res);
        let pathName = url.parse(req.url).pathname;
        let method = req.method.toLowerCase();
        let extname = path.extname(pathName); // 获取后缀名，如果有后缀名走的是静态web，如果没有后缀名就走的是路由
        if (!extname) {
            switch (method) {
                case 'get':
                    methods["_" + method][pathName](req, res)
                    break;
                case 'post':  // 新增封装的post请求
                    let postData = '';
                    req.on('data', (chunk) => {
                        postData += chunk
                    })
                    req.on('end', () => {
                        req.body = postData;
                        methods["_" + method][pathName](req, res)
                    })
                    break;

                default:
                    res.writeHead(404, {
                        "Content-Type": "text/html;charset=UTF-8"
                    });
                    res.end('页面不存在');
                    break;
            }
        }
    }

    app.get = function (pathName, cd) {
        methods._get[pathName] = cd;
    }
    app.post = function (pathName, cd) {
        methods._post[pathName] = cd;
    }
    return app;
}
module.exports = server();

封装访问静态web

app.js

const http = require('http');
const path = require('path');
const app = require('./modules/routers')

const ejs = require('ejs');

http.createServer(app).listen(3000);

app.static('./static');  // 访问静态web文件static

app.get('/login',(req,res)=>{
    ejs.renderFile(path.join(__dirname,'./views/form.ejs'),(err,data)=>{
        res.send(data);
    })
})
app.post('/doLogin',(req,res)=>{
    res.send(req.body);
})
app.get('/news',(req,res)=>{
    res.send();
})
app.get('/register',(req,res)=>{
    res.send('访问注册界面');
})

modules/routers.js中

const fs = require('fs');
const path = require('path');
const url = require('url');

function changeRes(req, res) {
    res['send'] = (str) => {
        res.writeHead(200, {
            "Content-Type": "text/html;charset=UTF-8"
        });
        res.end(str);
    }
}
// 静态web
function getFileMime(extraname) {
    let data = fs.readFileSync(path.join(__dirname, '../data/mime.json'));
    data = JSON.parse(data.toString())
    return data[extraname]
}
// 访问静态web的方法
function initStatic(req, res, staticPath) {
    let pathName = req.url; // 获取到请求的url
    pathName = url.parse(pathName).pathname; // 使用url内置模块获取路径名
    let extname = path.extname(pathName); // 使用内容模块path获取文件后缀名        
    try {
        let data = fs.readFileSync(staticPath + pathName);
        if (data) {
            let mime = getFileMime(extname); // 使用自定义模块根据后缀名获取Content-Type的值    
            res.writeHead(200, {
                "Content-Type": "" + mime + ";charset=UTF-8"
            });
            res.end(data);
        }
    } catch (error) {
    }
}

let server = () => {
    let methods = {
        _get: {},
        _post: {},
        staticPathName: '../static'  // 默认静态文件目录
    };

    let app = function (req, res) {
        changeRes(req, res);
        initStatic(req, res, methods.staticPathName);  // 执行访问静态web函数
        let pathName = url.parse(req.url).pathname;
        let method = req.method.toLowerCase();
        let extname = path.extname(pathName); // 获取后缀名，如果有后缀名走的是静态web，如果没有后缀名就走的是路由
        if (!extname) {
            switch (method) {
                case 'get':
                    methods["_" + method][pathName](req, res)
                    break;

                case 'post':
                    let postData = '';
                    req.on('data', (chunk) => {
                        postData += chunk
                    })
                    req.on('end', () => {
                        req.body = postData;
                        methods["_" + method][pathName](req, res)
                    })
                    break;

                default:
                    res.writeHead(404, {
                        "Content-Type": "text/html;charset=UTF-8"
                    });
                    res.end('页面不存在');
                    break;
            }
        }

    }

    app.get = function (pathName, cd) {
        methods._get[pathName] = cd;
    }
    app.post = function (pathName, cd) {
        methods._post[pathName] = cd;
    }
    app.static = function (staticPath) {
        methods.staticPathName = staticPath;
    }
    return app;
}
module.exports = server();

let data = fs.readFileSync(path.join(__dirname, '../data/mime.json'));

引入完整的对应关系需要使用一个json文件:https://github.com/wxyzcctv/node-demo-sd10/blob/main/data/mime.json
该json文件放在/data/mime.json