node.js + express 实现 json 文件数据获取与更新

读取与修改的方法

const fs = require('fs');
// promisify 异步处理
const { promisify } = require('util');
const path = require('path');

const readFile = promisify(fs.readFile)
const writeFile = promisify(fs.writeFile)

// 获取 json 数据
const getFileData = async (fileName) => {
  const filePath = path.join(__dirname, `../json/${fileName}.json`)
  const data = await readFile(filePath, 'utf-8')
  return JSON.parse(data)
}

// 修改 json 数据
const setFileData = async (fileName, data) => {
  const filePath = path.join(__dirname, `../json/${fileName}.json`)
  const datas = JSON.stringify(data, null, '  ')
  await writeFile(filePath, datas)
}

module.exports = {
  getFileData,
  setFileData
}

使用

const express = require('express');
const router = express.Router();

// 更新 json 数据
const { getFileData, setFileData } = require('../common')

// 用户注册
router.post('/api/register', async(req, res) => {
  // 获取所有用户信息
  const allUserInfo = await getFileData('userData')
  const allUserName = allUserInfo.map(user => user.userName)
  const { userName, password, sex } = req.body
  // 判断用户是否已注册
  if (allUserName.includes(userName)) {
    res.json({
      code: 200,
      data: null,
      success: false,
      message: '该用户已注册！'
    })
    return
  }
  if (!password) {
    res.json({
      code: 200,
      data: null,
      success: false,
      message: '请填写账号密码！'
    })
    return
  }
  if (!sex) {
    res.json({
      code: 200,
      data: null,
      success: false,
      message: '请选择性别！'
    })
    return
  }
  allUserInfo.push(req.body)
  setFileData('userData', allUserInfo)
  res.json({
    code: 200,
    data: null,
    success: true,
    message: '注册成功！'
  })
})

module.exports = router;