node 日志

我们主动控制的log4js，还有一些日志是继承好的，错误日志了，进程日志了，请求日志了。

1.

var express = require('express');
var logger = require('morgan');

var fs = require('fs');
var accessLog = fs.createWriteStream('access.log', {flags: 'a'});
var errorLog = fs.createWriteStream('error.log', {flags: 'a'});

var app = express();

app.use(logger('dev'));//这个是请求日志的打印

app.use(logger({stream: accessLog}));//进程日志

app.use(function (err, req, res, next) {
var meta = '[' + new Date() + '] ' + req.url + ' ';
errorLog.write(meta + err.stack + ' ');
next();
});