Express 4.x中间件morgan(logger)的详细解析

morgan 概述

http 请求日志记录中间件，详细请参考:(https://github.com/expressjs/morgan) or (http://npm.taobao.org/package/morgan)

入门示例

1.首先，初始化项目。

npm install express morgan

注：执行上面命名时应先安装express,详细参考：node快速构建express项目

2.在app.js中添加代码

var express = require('express');var app = express();var morgan = require('morgan');app.use(morgan('short'));app.use(function(req, res, next){    res.send('ok');});app.listen(3000);

3.运行程序查看效果

node bin\www 运行程序，并在浏览器里访问 http://127.0.0.1:3000控制台即可看到打印的日志如下：::ffff:127.0.0.1 - GET / HTTP/1.1 304 - - 3.019 ms::ffff:127.0.0.1 - GET /favicon.ico HTTP/1.1 200 2 - 0.984 ms

将日志打印到本地文件

morgan支持stream配置项，可以通过它来实现将日志写入文件便于查看。示例如下：

var express = require('express');var app = express();var morgan = require('morgan');var fs = require('fs');var path = require('path');var accessLogStream = fs.createWriteStream(path.join(__dirname, 'access.log'), {flags: 'a'});app.use(morgan('short', {stream: accessLogStream}));app.use(function(req, res, next){    res.send('ok');});app.listen(3000);

项目中实际应用记录

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 FileStreamRotator = require('file-stream-rotator')var path = require('path')var fs=require('fs');var logDirectory = path.join(__dirname, 'logs')var index = require('./routes/index');var users = require('./routes/users');var app = express();// view engine setupapp.set('views', path.join(__dirname, 'views'));app.set('view engine', 'jade');// ensure log directory existsfs.existsSync(logDirectory) || fs.mkdirSync(logDirectory)// create a rotating write streamvar accessLogfile = FileStreamRotator.getStream({  date_format: 'YYYY-MM-DD',  filename: path.join(logDirectory, 'access-%DATE%.log'),  frequency: 'daily',  verbose: false})var errorLogfile = FileStreamRotator.getStream({  date_format: 'YYYY-MM-DD',  filename: path.join(logDirectory, 'error-%DATE%.log'),  frequency: 'daily',  verbose: false})// 对Date的扩展，将 Date 转化为指定格式的String// 月(M)、日(d)、小时(h)、分(m)、秒(s)、季度(q) 可以用 1-2 个占位符， // 年(y)可以用 1-4 个占位符，毫秒(S)只能用 1 个占位符(是 1-3 位的数字) // 例子： // (new Date()).Format("yyyy-MM-dd hh:mm:ss.S") ==> 2006-07-02 08:09:04.423 // (new Date()).Format("yyyy-M-d h:m:s.S")      ==> 2006-7-2 8:9:4.18 Date.prototype.Format = function (fmt) { //author: meizz     var o = {        "M+": this.getMonth() + 1, //月份         "d+": this.getDate(), //日         "h+": this.getHours(), //小时         "m+": this.getMinutes(), //分         "s+": this.getSeconds(), //秒         "q+": Math.floor((this.getMonth() + 3) / 3), //季度         "S": this.getMilliseconds() //毫秒     };    if (/(y+)/.test(fmt)) fmt = fmt.replace(RegExp.$1, (this.getFullYear() + "").substr(4 - RegExp.$1.length));    for (var k in o)    if (new RegExp("(" + k + ")").test(fmt)) fmt = fmt.replace(RegExp.$1, (RegExp.$1.length == 1) ? (o[k]) : (("00" + o[k]).substr(("" + o[k]).length)));    return fmt;}// 自定义tokenlogger.token('from', function(req, res){    return JSON.stringify(req.query) || '-';});logger.token('time', function(req, res){    return new Date().Format("yyyy-MM-dd hh:mm:ss"); });logger.token('nextROw', function(req, res){    return "\r\n"; });// 自定义format，其中包含自定义的tokenlogger.format('joke', '[joke] :time :remote-addr :remote-user :method :url :from :status :referrer :response-time ms :user-agent :nextROw');//跳过不需要记录的请求function skip (req) {        return (req.url).indexOf('stylesheets') != -1      }// 使用自定义的formatapp.use(logger('joke'));app.use(logger('joke',{skip: skip, stream: accessLogfile })); //打印到日志文件中  app.use(bodyParser.json());app.use(bodyParser.urlencoded({ extended: false }));app.use(cookieParser());app.use(express.static(path.join(__dirname, 'public')));app.use('/', index);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 handlerapp.use(function(err, req, res, next) {     var now = new Date();        var time = now.getFullYear() + '-' + now.getMonth() + '-' + now.getDate() + ' '            + now.getHours() + ':' + now.getMinutes() + ':' + now.getSeconds();        var meta = '[' + time + '] '+req.method+' ' + req.url + '\r\n';        errorLogfile.write(meta + err.stack + '\r\n\r\n\r\n');        next();  // set locals, only providing error in development  res.locals.message = err.message;  res.locals.error = req.app.get('env') === 'development' ? err : {};  // render the error page  res.status(err.status || 500);  res.render('error');});module.exports = app;

相关链接

http://m.blog.csdn.net/sunq1982/article/details/77504056
https://www.cnblogs.com/chyingp/p/node-learning-guide-express-morgan.html
https://github.com/expressjs/morgan
http://npm.taobao.org/package/morgan
https://www.cnblogs.com/yanhua2017/p/6385494.html