筆記

var http=require("http");//引入http模塊
var fs=require("fs");//引入文件讀寫模塊
var url=require("url");//引入url處理模塊
var server=new http.Server();//實例化一個服務器對象
//監聽請求事件
server.on("request",(req,res)=>{
  var pathname=url.parse(req.url).pathname;//請求路徑
  switch(pathname){//路徑分析。根據不同的路徑返回不同的資源
    case ""||"/":
    
  }
});

作業：完善上的代碼，實現一個靜態資源服務器。

作用

完善課上的代碼實現一個靜態資源服務器。

創建三個文件：程序入口文件app.js、資源映射文件mime.js、配置文件config.js

程序入口文件app.js

var http = require("http");
var url = require("url");
var fs = require("fs");
var path = require("path");
var zlib = require("zlib");//壓縮模塊
var mime = require("./mime").types;
var config = require("./config");
var server = new http.Server();
server.on("request", function (request, response) {//監聽請求事件
    var pathname = url.parse(request.url).pathname;

    switch(pathname){//路由控制；
        case "/"||"index":
            pathname="/index.html";
            break;
    }

    var realPath = path.join("assets", path.normalize(pathname));
    var ext = path.extname(realPath);//解析文件的后綴名；
    if(ext){//不處理沒有后綴名的realPath,這一點交給路由控制；
        fs.stat(realPath, function (err, stat) {//讀取文件屬性
            if (err) {//如果沒找到文件返回404
                response.writeHead(404, "Not Found", {'Content-Type': 'text/plain'});
                response.write("NOT FOUND on this server");
                response.end();
            } else {
                ext = ext.slice(1);
                var contentType = mime[ext] || "text/plain";
                response.setHeader('Content-Type', contentType);
                var lastModified = stat.mtime.toUTCString();//文件的最后修改時間
                response.setHeader("Last-Modified", lastModified);
                if (ext.match(config.Expires.fileMatch)) {//緩存
                    var expires = new Date();
                    expires.setTime(expires.getTime() + config.Expires.maxAge * 1000);
                    response.setHeader("Expires", expires.toUTCString());
                    response.setHeader("Cache-Control", "max-age=" + config.Expires.maxAge);
                }
                if (request.headers["if-modified-since"] && lastModified == request.headers["if-modified-since"]) {//判斷文件是否修改過
                    response.writeHead(304, "Not Modified");
                    response.end();
                } else {如果修改過或者第一次傳輸則返回文件
                    var raw = fs.createReadStream(realPath);
                    var ae = request.headers["accept-encoding"] || "";//獲取瀏覽器支持的壓縮格式
                    var matched = ext.match(config.Compress.match);
                    if (matched && ae.match(/\bgzip\b/)) {
                        response.writeHead(200, "ok", {"Content-Encoding": "gzip"});
                        raw.pipe(zlib.createGzip()).pipe(response);
                    } else if (matched && ae.match(/\bdeflate\b/)) {
                        response.writeHead(200, "ok", {"Content-Encoding": "deflate"});
                        raw.pipe(zlib.createDeflate()).pipe(response);
                    } else {//如果不支持壓縮，則直接傳輸
                        response.writeHead(200, "ok");
                        raw.pipe(response);
                    }
                }
            }
        });
    }else{//如果沒有后綴名，則直接斷開連接
        response.end();
    }
});
server.listen(3000);

資源映射文件mime.js

exports.types = {

    "css": "text/css",

    "gif": "image/gif",

    "html": "text/html",

    "ico": "image/x-icon",

    "jpeg": "image/jpeg",

    "jpg": "image/jpeg",

    "js": "text/javascript",

    "json": "application/json",

    "pdf": "application/pdf",

    "png": "image/png",

    "svg": "image/svg+xml",

    "swf": "application/x-shockwave-flash",

    "tiff": "image/tiff",

    "txt": "text/plain",

    "wav": "audio/x-wav",

    "wma": "audio/x-ms-wma",

    "wmv": "video/x-ms-wmv",

    "xml": "text/xml"

};

配置文件config.js

exports.Expires = {//緩存
  fileMatch: /^(gif|png|jpg|js|css)$/ig,//需要緩存的文件類型
  maxAge: 60*60*24*365//到期時間
};
exports.Compress={//需要壓縮傳輸的文件類型
  match:/css|js|html/ig
};