Node入门的一本电子书

Node入门

本书最后实现了一个简易Node应用，对于入门Node的同学，理解模块、阻塞、事件驱动等概念有很大帮助。

server.js

var formidable = require("formidable");
var http = require("http");
var url = require("url");

function start(route,handler) {
    function onRequest(req,res) {
        var postData = "";

        var pathname = url.parse(req.url).pathname;
        console.log("Request for " + pathname + " received.");
        
        if (pathname === "/favicon.ico") return;    

        route(handler,pathname,res,req);
    }

    http.createServer(onRequest).listen(8888);
    console.log("Server has started for : http://localhost:8888");
}

exports.start = start;

router.js

function route(handle,pathname,res,req) {
    console.log("About to route a request for " + pathname);

    if (typeof handle[pathname] === "function") {
        return handle[pathname](res,req);
    } else {
        console.log("Error! No request handler found for " + pathname);
    }

}

exports.route = route;

reqHandlers.js

var querystring = require("querystring"),
    fs = require("fs"),
    formidable = require("formidable");

function start(res) {
    console.log("Request handler 'start' was called.");
  
    var body = '<html>' +
        '<head>' +
        '<meta http-equiv="Content-Type" ' +
        'content="text/html; charset=UTF-8" />' +
        '</head>' +
        '<body>' +
        '<form action="/upload" enctype="multipart/form-data" ' +
        'method="post">' +
        '<input type="file" name="upload">' +
        '<input type="submit" value="Upload file" />' +
        '</form>' +
        '</body>' +
        '</html>';
    
    res.writeHead(200,{"Content-Type":"text/html"});
    res.write(body);
    res.end();
}
function upload(res,req) {
    console.log("Request handler 'upload' was called.");
    
    // 可以试着打印req对象，查看如何解析的

    var form = new formidable.IncomingForm();
    console.log("form 正在解析 post");

    form.parse(req,function(error,fields,files) {
        console.log("解析完成");
        // 重命名图片，确保show正确
        console.log(files.upload.path);

        fs.renameSync(files.upload.path, "./tmp/test.png"); 

        res.writeHead(200, {"Content-Type": "text/html"});
        res.write("received image:<br/>");
        res.write("<img src='/show' />");
        res.end();
    })
}

function show(res) {
    console.log("Request handler 'show' was called");
    fs.readFile("./tmp/test.png","binary",function(error,file) {
        if (error) {
            res.writeHead(500, {"Content-Type": "text/plain"});
            res.write(error + "\n");
            res.end();
        } else {
            res.writeHead(200, {"Content-Type": "image/png"});
            res.write(file, "binary");
            res.end();
        }
    })
}

exports.start = start;
exports.upload = upload;
exports.show = show;

main.js

var server = require("./server");
var router = require("./router");
var reqhandlers = require("./reqHandlers");

var handler = {};
handler["/"] = reqhandlers.start;
handler["/start"] = reqhandlers.start;
handler["/upload"] = reqhandlers.upload;
handler["/show"] = reqhandlers.show;

server.start(router.route,handler);

Node入门的一本电子书

Node入门

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