var express = require(‘express‘);var path = require(‘path‘);var favicon = require(‘serve-favicon‘);var logger = require(‘morgan‘);var cookieParser = require(‘cookie-parser‘);var bodyParser = require(‘body-parser‘);var routes = require(‘./routes/index‘);var users = require(‘./routes/users‘);var app = express();// 设置views路径和模板
//__dirname是node.js里面的全局变量，即取得执行的js所在的路径，另外__dirname是目前执行的js文件名。所以，app.set(‘views’, __dirname + ‘/views’);是设置views的文件//夹。
app.set(‘views‘, path.join(__dirname, ‘views‘));
//设置express.js所使用的render engine。除了Jade之外，express.js还支持EJS(embedded javascript)、Haml、CoffeScript和jQuery template等js模板。app.set(‘view engine‘, ‘jade‘);// uncomment after placing your favicon in /public//app.use(favicon(__dirname + ‘/public/favicon.ico‘));
//app.use配置

app.use(logger(‘dev‘));app.use(bodyParser.json());app.use(bodyParser.urlencoded({ extended: false }));app.use(cookieParser());app.use(express.static(path.join(__dirname, ‘public‘)));app.use(‘/‘, routes);app.use(‘/users‘, users);// catch 404 and forward to error handlerapp.use(function(req, res, next) {    var err = new Error(‘Not Found‘);    err.status = 404;    next(err);});// error handlers// development error handler// will print stacktraceif (app.get(‘env‘) === ‘development‘) {    app.use(function(err, req, res, next) {        res.status(err.status || 500);        res.render(‘error‘, {            message: err.message,            error: err        });    });}// production error handler// no stacktraces leaked to userapp.use(function(err, req, res, next) {    res.status(err.status || 500);    res.render(‘error‘, {        message: err.message,        error: {}    });});module.exports = app;