错误处理日志

const express = require('express');
const fs = require('fs');
const path = require('path');
const app = express();

app.get('/', (req, res, next)=>{
    try {
        const data = JSON.parse('{name:');//试验错误
        res.json(data);
    }catch (e) {
        //抛出错误
        next(e);
    }
});

app.get('/b', (req, res, next)=>{
    fs.readFile(path.join(__dirname, 'ccccc.log'), (err, data)=>{
        if(err){
            next(err);
        }
    });
});

app.get('/a', (req, res, next)=>{
    res.send('<h1>Hello World!</h1>');
});


/*
  统一的错误处理日志
*/
app.use((err, req, res, next)=>{
    const error_log = `
    =====================================
    错误名: ${err.name}, \n
    错误信息:${err.message}, \n
    错误时间:${new Date()}, \n
    错误堆栈:${err.stack}, \n
    =====================================
    `;
    fs.appendFile(path.join(__dirname, 'error.log'), error_log, (err)=>{
        res.writeHead(500, {'Content-Type': 'text/html;charset=utf-8'});
        res.end('500 服务器内部错误!')
    });
});

app.use((req, res, next)=>{
    res.writeHead(404, {'Content-Type': 'text/html;charset=utf-8'});
    res.end('404 您访问的资源不存在!')
});

app.listen(3000, ()=>{
   console.log('running.....')
});