怎样在项目中使用log4.js的方法步骤

// config.js

let path = require('path');

// 日志根目录
let baseLogPath = path.resolve(__dirname, '../../../logs');
// 请求日志目录
let reqPath = '/request';
// 请求日志文件名
let reqFileName = 'request';
// 请求日志输出完整路径
let reqLogPath = baseLogPath + reqPath + '/' + reqFileName;


// 响应日志目录
let resPath = '/response';
// 响应日志文件名
let resFileName = 'response';
// 响应日志输出完整路径
let resLogPath = baseLogPath + resPath + '/' + resFileName;

// 错误日志目录
let errPath = '/error';
// 错误日志文件名
let errFileName = 'error';
// 错误日志输出完整路径
let errLogPath = baseLogPath + errPath + '/' + errFileName;


module.exports = {
  appenders: {
    // 所有的日志
    'console': {type: 'console'},
    // 请求日志
    'reqLogger': {
      type: 'dateFile', // 日志类型
      filename: reqLogPath, // 输出文件名
      pattern: '-yyyy-MM-dd-hh.log', // 后缀
      alwaysIncludePattern: true, // 上面两个参数是否合并
      encoding: 'utf-8', // 编码格式
      maxLogSize: 1000, // 最大存储内容
    },
    // 响应日志
    'resLogger': {
      type: 'dateFile',
      filename: resLogPath,
      pattern: '-yyyy-MM-dd-hh.log',
      alwaysIncludePattern: true,
      encoding: 'utf-8',
      maxLogSize: 1000,
    },
    // 错误日志
    'errLogger': {
      type: 'dateFile',
      filename: errLogPath,
      pattern: '-yyyy-MM-dd-hh.log',
      alwaysIncludePattern: true,
      encoding: 'utf-8',
      maxLogSize: 1000,
    }
  },
  // 分类以及日志等级
  categories: {
    default: {
      appenders: ['console'],
      level: 'all'
    },
    reqLogger: {
      appenders: ['reqLogger'],
      level: 'info'
    },
    resLogger: {
      appenders: ['resLogger'],
      level: 'info'
    },
    errLogger: {
      appenders: ['errLogger'],
      level: 'error'
    }
  },
}

// 先安装log4js

// log4.js

const log4Config = require('./config')
const log4js = require('log4js')

// 调用配置文件
log4js.configure(log4Config)


class CommonHandle {
  constructor(){}
  // 格式化请求日志
  static formatReqLog(ctx, time){
    let text = '------------request start------------'
    let method = ctx.method
    text += `request method: ${method} \n request url: ${ctx.originalUrl } \n`

    if(method = 'GET'){
      text += `request data: ${JSON.stringify(ctx.query)} \n`
    }else{
      text += `request data: ${JSON.stringify(ctx.body)} \n`
    }
    text += `ctx all: ${JSON.stringify(ctx)}`
    return text
  }
  // 格式化相应日志
  static formatResLog(ctx,time){
    let text = '------------response start------------'
    text += `response result: ${JSON.stringify(ctx.response.body)} \n`

    text += `response all: ${JSON.stringify(ctx)} \n`

    text += `response time: ${time} \n`
    return text
  }
  // 格式化错误日志
  static formatErrorLog(ctx,error,time){
    let text = '------------error start------------'
    text += this.formatResLog(ctx,time)
    text += `error content: ${JSON.stringify(error)}`

    return text
  }
}

class HandleLogger extends CommonHandle{
  constructor(){
    super()
  }

  // 请求日志
  static reqLogger(ctx){
    log4js.getLogger('reqLogger').info(this.formatReqLog(ctx))
  }

  // 相应日志
  static resLogger(ctx, time){
    log4js.getLogger('resLogger').info(this.formatResLog(ctx,time))
  }

  // 错误日志
  static errorLogger(ctx, error, time){
    log4js.getLogger('errLogger').info(this.formatErrorLog(ctx,error,time))
  }

}





module.exports = (options) => {
  return async (ctx,next) => {
    const startTime = new Date()
    let period;
    try{
      // 请求日志
      HandleLogger.reqLogger(ctx)
      await next()
      period = new Date() - startTime
      // 响应日志
      HandleLogger.resLogger(ctx,period)
    }catch(err){
      period = new Date() - startTime
      // 错误日志
      HandleLogger.errorLogger(ctx, err, period)
    }
  }
}

// app.js

const Koa = require('koa')
const app = new Koa()
const LogJS = require('./common/log/log4')

// log4.js引入
app.use(LogJS())