Tap Open the door of Nodejs--The first Nodejs entry program

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Many languages to learn. Recently began to write Nodejs, there is a little tired to say. Overview

This article is mainly recorded in today's introductory Nodejs write a few code, is also a small program. The following code should all be developed according to this pattern, but the framework should be used later, so there will be a certain difference in development.

The following code is the main: Import program > Server > Routing > handler, and the request response is based on such logic to layer depth.

This is just a simple record and hopefully it will get better later. For more details, visit node Getting started. Entry Program (index.js)

As a portal to the Web site
//and boot to the server

var server = require ('./server ');
var router = require ('./router ');
var requesthandlers = require ('./requesthandlers ');

Handle is an object that can add member properties and member functions through key value pairs
var handle = {}
//through such a data structure, you can effectively replace the switch and if structure
//So that the code will be more concise, clear
handle['/'] = Requesthandlers.start;
handle['/start '] = Requesthandlers.start;
handle['/upload '] = requesthandlers.upload;
handle['/index '] = Requesthandlers.index;
handle['/show '] = requesthandlers.show;

Server.start (router.route,handle);

/* Request "Server" "
Routing" process

Server (server.js)

HTTP server, can process requests, can also put requests into the handler to process//boot to the route, route to different paths to different processing methods, specific processing in the Handler//http module var http = require (' http ');
var url = require (' URL ');

        This will router boot function start (route, handle) {function onrequest (request,response) {var postdata = '] from the server.
        var pathname = Url.parse (request.url). Pathname;

        Console.log (' request for ' + pathname + ' received ');
        The server serves as the direct end of the receiving user request, where the server's request//Set encoding format is directly request.setencoding (' UTF8 '); Adds a listener event for callback processing//Processing requests Request.addlistener (' Data ', function (postdatachunk) {postdata = P
            Ostdatachunk;

        Console.log (' Receive Post data chunk ' + PostData + '. ');});
        Process the requested program Request.addlistener (' End ', function () {route (handle, pathname, response, postdata);

        });
        Response.writehead ({' Content-type ': ' Text/plain '});
        Response.Write (content);
    Response.End (); //Call function, which returns an object that has a method lisTen, and specifies that a function that listens on the port//As a parameter is an object of the callback function//callback function used as a callback, each of which has its own method Http.createserver (ONrequest). Listen (8080);
Console.log (' Server has started ');
 }//Modular, export function (function) Exports.start = start;

Routing (router.js)

Mapping different URLs to requests booting to different request handlers
//directing the path

function route (handle, Pathname,response,postdata) {
    Console.log (' About to route a request for ' + pathname);
    if (typeof handle[pathname] = = ' function ') {
        //If it is a function, then run
        //Take advantage of this type of associative array, it can be code concise and fluent
        Handle[pathname] ( Response, PostData);
    else{
        console.log (' No request handler found for ' + pathname);
        Response.writehead (404, {' Content-type ': ' Text/plain '});
        Response.Write (' 404 Not Found ');
        Response.End ();
    }

Exports.route = route;

processing program (requesthandlers.js)

Handler, dealing with the specific business logic var exec = require (' child_process '). exec;
var querystring = require (' querystring '); var fs = require (' FS ');
    Read local file external module function start (response, PostData) {console.log (' start ');
        function sleep (milliseconds) {var starttime = new Date (). GetTime ();
    while (new Date (). GetTime () < StartTime + milliseconds); //Start a child thread for each request processing//Hibernation 10s exec (' dir/s/a C: ', {timeout:10000, maxbuffer:20000*1024},function (error,stdout,st
        Derr) {//Sleep (10 * 1000);
        Response.writehead (200,{' content-type ': ' Text/plain '});
        Response.Write (stdout);
    Response.End ();
});

    } function Index (response, postdata) {console.log (' index ');
        var body = '