var express = require('express');
var app = express();
// respond with "hello world" when a GET request is made to the homepage
app.get('/', function(req, res) {
 res.send('hello world');
});

// GET method route
app.get('/', function (req, res) {
 res.send('GET request to the homepage');
});
// POST method route
app.post('/', function (req, res) {
 res.send('POST request to the homepage');
});

app.all('/secret', function (req, res, next) {
 console.log('Accessing the secret section ...');
 next(); // pass control to the next handler
});

// 匹配根路径的请求
app.get('/', function (req, res) {
 res.send('root');
});
// 匹配 /about 路径的请求
app.get('/about', function (req, res) {
 res.send('about');
});
// 匹配 /random.text 路径的请求
app.get('/random.text', function (req, res) {
 res.send('random.text');
});
使用字符串模式的路由路径示例：
// 匹配 acd 和 abcd
app.get('/ab?cd', function(req, res) {
 res.send('ab?cd');
});
// 匹配 abcd、abbcd、abbbcd等
app.get('/ab+cd', function(req, res) {
 res.send('ab+cd');
});
// 匹配 abcd、abxcd、abRABDOMcd、ab123cd等
app.get('/ab*cd', function(req, res) {
 res.send('ab*cd');
});
// 匹配 /abe 和 /abcde
app.get('/ab(cd)?e', function(req, res) {
 res.send('ab(cd)?e');
});

// 匹配任何路径中含有 a 的路径：
app.get(/a/, function(req, res) {
 res.send('/a/');
});
// 匹配 butterfly、dragonfly，不匹配 butterflyman、dragonfly man等
app.get(/.*fly$/, function(req, res) {
 res.send('/.*fly$/');
});

app.get('/example/a', function (req, res) {
 res.send('Hello from A!');
});

app.get('/example/b', function (req, res, next) {
 console.log('response will be sent by the next function ...');
 next();
}, function (req, res) {
 res.send('Hello from B!');
});

var cb0 = function (req, res, next) {
 console.log('CB0');
 next();
}
var cb1 = function (req, res, next) {
 console.log('CB1');
 next();
}
var cb2 = function (req, res) {
 res.send('Hello from C!');
}
app.get('/example/c', [cb0, cb1, cb2]);

var cb0 = function (req, res, next) {
 console.log('CB0');
 next();
}
var cb1 = function (req, res, next) {
 console.log('CB1');
 next();
}
app.get('/example/d', [cb0, cb1], function (req, res, next) {
 console.log('response will be sent by the next function ...');
 next();
}, function (req, res) {
 res.send('Hello from D!');
});