• 从零开始学习Node.js例子四 多页面实现数学运算


    app-node.js

    var http_port = 3000;
    
    var http = require('http');
    var htutil = require('./htutil');
    
    var server = http.createServer(function(req, res){
        htutil.loadParams(req, res, undefined);
        if (req.requrl.pathname === '/'){
            require('./home-node').get(req, res);
        }else if (req.requrl.pathname === '/square'){
            require('./square-node').get(req, res);
        }else if (req.requrl.pathname === '/factorial'){
            require('./factorial-node').get(req, res);
        }else if (req.requrl.pathname === '/fibonacci'){
            require('./fibo-node').get(req, res);
        }else if (req.requrl.pathname === '/mult'){
            require('./mult-node').get(req, res);
        }else{
            res.writeHead(404, {'Content-Type': 'text/plain'});
            res.end("bad URL" + req.url);
        }
    });
    
    server.listen(http_port);
    console.log('listening to http://localhost:3000');

    htutil.js

    var url = require('url');
    exports.loadParams = function(req, res, next){
        req.requrl = url.parse(req.url, true);
        req.a = (req.requrl.query.a && !isNaN(req.requrl.query.a))
            ? new Number(req.requrl.query.a)
            : NaN;
        req.b = (req.requrl.query.b && !isNaN(req.requrl.query.b))
            ? new Number(req.requrl.query.b)
            : NaN;
        if(next) next();
    }
    
    exports.navbar = function(){
        return ["<div class='navbar'>",
            "<p><a href='/'>home</a></p>",
            "<p><a href='/mult'>Multiplication</a></p>",
            "<p><a href='/square'>Square</a></p>",
            "<p><a href='/factorial'>Factorial</a></p>",
            "<p><a href='/fibonacci'>Fibonacci</a></p>",
            "</div>"].join('
    ');
    }
    
    exports.page = function(title, navbar, content){
        return ["<html><head><title>{title}</title></head>",
            "<body><h1>{title}</h1>",
            "<table><tr>",
            "<td>{navbar}</td><td>{content}</td>",
            "</tr></table></body></html>"
            ].join('
    ')
            .replace(new RegExp("{title}", "gm"), title)
            .replace("{navbar}", navbar)
            .replace("{content}", content);
    }

    home-node.js

    var htutil = require('./htutil');
    
    exports.get = function(req, res){
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end(htutil.page("Math Wizard", htutil.navbar(), "<p>Math Wizard</p>"));
    }

    square-node.js

    var htutil = require('./htutil');
    exports.get = function(req, res){
        res.writeHead(200, {'Content-Type': 'text/html'});
        var result = req.a * req.a;
        res.end(
            htutil.page("Square", htutil.navbar(), [
                (!isNaN(req.a) ?
                    ("<p class='result'>{a} squared = {sq}</p>"
                        .replace("{a}", req.a)
                        .replace("{sq}", req.a * req.a))
                    : ""),
                "<p>Enter numbers to see its square</p>",
                "<form name='square' action='/square' method='get'>",
                "A: <input type='text' name='a' /><br/>",
                "<input type='submit' value='Submit' />",
                "</form>"
            ].join('
    '))
        );
    }

    factorial-node.js

    var htutil = require('./htutil');
    var math = require('./math');
    
    exports.get = function(req, res){
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end(
            htutil.page("Factorial", htutil.navbar(), [
                (!isNaN(req.a) ?
                    ("<p class='result'>{a} factorial = {fact}</p>"
                        .replace("{a}", req.a)
                        .replace("{fact}", math.factorial(Math.floor(req.a))))
                    : ""),
                "<p>Enter numbers to see its factorial</p>",
                "<form name='factorial' action='/factorial' method='get'>",
                "A: <input type='text' name='a' /><br/>",
                "<input type='submit' value='Submit' />",
                "</form>"
            ].join('
    '))
        );
    }

    mult-node.js

    var htutil = require('./htutil');
    exports.get = function(req, res){
        res.writeHead(200, {'Content-Type': 'text/html'});
        var result = req.a * req.b;
        res.end(
            htutil.page("Multiplication", htutil.navbar(), [
                (!isNaN(req.a) && !isNaN(req.b) ?
                    ("<p class='result'>{a} * {b} = {result}</p>"
                        .replace("{a}", req.a)
                        .replace("{b}", req.b)
                        .replace("{result}", req.a * req.b))
                    : ""),
                "<p>Enter numbers to mutiply</p>",
                "<form name='mult' action='/mult' method='get'>",
                "A: <input type='text' name='a' /><br/>",
                "B: <input type='text' name='b' /><br/>",
                "<input type='submit' value='Submit' />",
                "</form>"
            ].join('
    '))
        );
    }

    fibo-node.js

    var htutil = require('./htutil');
    var math = require('./math');
    
    exports.get = function(req, res){
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end(
            htutil.page("Fibonacci", htutil.navbar(), [
                (!isNaN(req.a) ?
                    ("<p class='result'>{a} fibonacci = {fibo}</p>"
                        .replace("{a}", Math.floor(req.a))
                        .replace("{fibo}", math.fibonacci(Math.floor(req.a))))
                    : ""),
                "<p>Enter numbers to see its fibonacci</p>",
                "<form name='fibonacci' action='/fibonacci' method='get'>",
                "A: <input type='text' name='a' /><br/>",
                "<input type='submit' value='Submit' />",
                "</form>"
            ].join('
    '))
        );
    }

    fibo2-node.js

    var htutil = require('./htutil');
    var math = require('./math');
    
    function sendResult(req, res, a, fiboval){
        res.writeHead(200, {'Content-Type': 'text/html'});
        res.end(
            htutil.page("Fibonacci", htutil.navbar(), [
                (!isNaN(fiboval) ?
                    ("<p class='result'>{a} fibonacci = {fibo}</p>"
                        .replace("{a}", a)
                        .replace("{fibo}", fiboval))
                    : ""),
                "<p>Enter numbers to see its fibonacci</p>",
                "<form name='fibonacci' action='/fibonacci' method='get'>",
                "A: <input type='text' name='a' /><br/>",
                "<input type='submit' value='Submit' />",
                "</form>"
            ].join('
    '))
        );
    }
    
    exports.get = function(req, res){
        if (!isNaN(req.a)){
            math.fibonacciAsync(Math.floor(req.a), function(val){
                sendResult(req, res, Math.floor(req.a) ,val);
            });
        }else {
            sendResult(req, res, NaN, NaN);
        }
    }

    math.js

    var factorial = exports.factorial = function(n){
        if (n == 0)
            return 1;
        else
            return n * factorial(n-1);
    }
    
    var fibonacci = exports.fibonacci = function(n){
        if (n === 1)
            return 1;
        else if (n === 2)
            return 1;
        else
            return fibonacci(n-1) + fibonacci(n-2);
    }
    
    var fibonacciAsync = exports.fibonacciAsync = function(n, done){
        if (n ==1 || n == 2)
            done(1);
        else {
            process.nextTick(function(){
                fibonacciAsync(n-1, function(val1){
                    process.nextTick(function(){
                        fibonacciAsync(n-2, function(val2){
                            done(val1 + val2);
                        });
                    })
                });
            });
        }
    }

      

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  • 原文地址:https://www.cnblogs.com/EricaMIN1987_IT/p/3641328.html
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