1.1项目结构

1.2 babel环境配置

下载

javascript 复制代码

yarn add @babel/cli @babel/core @babel/node @babel/preset-env babel-loader babel-plugin-module-resolver -D

配置

javascript 复制代码

{
    "presets": ["@babel/preset-env"],
    "plugins": [
      ["module-resolver", {
        "root": ["./src"],
        "alias": {
          "@": "./src"
        }
      }]
    ]
  }

1.3webpack打包配置

下载

javascript 复制代码

yarn add webpack-cli webpack webpack-dev-middleware webpack-hot-middleware webpack-merge

配置

根目录下新建webpack.common.js,webpack.pro.js,webpack.dev.js

拆分webpack

分公共，生产，开发不同环境打包配置

配置代码

公共配置

javascript 复制代码

const path = require('path');
const webpack = require('webpack');
module.exports = {
  target: 'node',
  entry: './src/app.js',
  output: {
    path: path.resolve(__dirname, 'dist/js'),
    filename: '[name].[contenthash].js',
    clean: true,
  },
  mode: "production",
  resolve:{
    alias:{
      extensions: ['.js', '.json'],
    //＠符号表示 src 这一层目录
    '@': path.resolve(__dirname, './src')
    }
  },
  module: {
    rules: [
      {
        test: /\.js$/,
        exclude: /node_modules/,
        use: {
          loader: 'babel-loader',
          options: {
            presets: ['@babel/preset-env'],
          },
        },
      },
    ],
  },
  externals: {
    'sequelize':"require('sequelize')"
  },
  resolve: {
    extensions: ['.js'],
  },
  optimization: {
    splitChunks: {
      chunks: 'all',
    },
    minimize: true,
  },
  plugins: [
    new webpack.ProgressPlugin(),
  ],

};

开发环境

javascript 复制代码

const { merge } = require('webpack-merge');
const commonConfig = require('./webpack.common');

module.exports = merge(commonConfig, {
  mode: 'development',
});

生产环境

javascript 复制代码

const { merge } = require('webpack-merge');
const commonConfig = require('./webpack.common');

module.exports = merge(commonConfig, {
  mode: 'production',
});

1.4package.json配置

json 复制代码

{
  "name": "koa_service",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "nodemon --watch @/ --exec babel-node ./src/app.js",
    "build": "webpack --config ./build/webpack.prod.js && xcopy .env dist && xcopy ecosystem.config.js dist",
    "build:dev": "webpack --config ./build/webpack.dev.js && xcopy .env dist && xcopy ecosystem.config.js dist"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "@babel/cli": "^7.23.4",
    "@babel/core": "^7.23.7",
    "@babel/node": "^7.22.19",
    "@babel/preset-env": "^7.23.8",
    "babel-loader": "^9.1.3",
    "babel-plugin-module-resolver": "^5.0.0",
    "dotenv": "^16.3.1",
    "fs": "^0.0.1-security",
    "koa": "^2.14.2",
    "koa-bodyparser": "^4.4.1",
    "koa-cors": "^0.0.16",
    "koa-ip": "^2.1.3",
    "koa-router": "^12.0.1",
    "mysql2": "^3.6.3",
    "sequelize": "^6.35.0",
    "webpack": "^5.89.0",
    "webpack-cli": "^5.1.4",
    "webpack-dev-middleware": "^6.1.1",
    "webpack-hot-middleware": "^2.25.4",
    "webpack-merge": "^5.10.0"
  },
  "devDependencies": {
    "@babel/plugin-transform-runtime": "^7.23.7",
    "@babel/runtime": "^7.23.8",
    "nodemon": "^3.0.1"
  }
}

2.配置koa

2.1安装 Koa 框架

javascript 复制代码

yarn add koa

2.2 编写入口文件

javascript 复制代码

const Koa = require('koa')

const app = new Koa()

app.use((ctx, next) => {
  ctx.body = 'ws'
})

app.listen(3000, () => {
  console.log('server is running on http://localhost:3000')
})

2.3使用nodemon

安装nodemon

javascript 复制代码

yarn add nodemon -D

配置nodemon

json 复制代码

{
  "name": "koa_service",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "nodemon ./src/app.js",
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "koa": "^2.14.2",
  },
  "devDependencies": {
    "nodemon": "^3.0.1"
  }
}

nodemon使用成功

2.4解析body参数

安装koa-bodyparser

javascript 复制代码

yarn add koa-bodyparser

在app/index.js入口配置文件注册

javascript 复制代码

const koa = require("koa");
const app = new koa();
// 处理post参数解析中间件
app.use(bodyParser());
module.exports = app;

2.5解决跨域

安装koa-cors

yarn add koa-cors

javascript 复制代码

const Koa = require("koa");
const cors = require("koa-cors");
const app = new Koa();
//处理跨域问题中间件
app.use(cors());

2.6获取ip

安装koa-ip

yarn add koa-ip

配置

javascript 复制代码

/*
 * @Description:
 * @Author: Wang Su
 * @Date: 2023-09-16 23:31:37
 * @LastEditors: Wang Su
 * @LastEditTime: 2023-09-21 14:36:46
 */
const Koa = require("koa");
const ip = require("koa-ip");
//获取用户ip的中间件
app.use(
  ip({
    checkProxyHeaders: true, // 选项示例
  })
);

const port = 19001;
app.listen(port, () => {
  console.log(`19001端口服务启用`);
});

3.config配置层

3.1根目录新建.env文件

typescript 复制代码

# 后端服务端口号
APP_PORT=19801
# 数据库主机
MYSQL_HOST="localhost"
# 数据库端口号
MYSQL_PORT=3306
# 数据库用户名
MYSQL_USERNAME="root"
# 数据库的密码
MYSQL_PASSWORD="123456"
# 连接数据库连接名
MYSQL_DB="koa"

3.2使用dotenv

安装dotenv

javascript 复制代码

yarn add dotenv

配置dotenv

javascript 复制代码

const dotenv=require("dotenv")
dotenv.config()
module.exports=process.env

在入口文件引入config.default.js

typescript 复制代码

const {APP_PORT}=require("./config/config.default.js")
const app =require("./app/index.js")
app.listen(APP_PORT,()=>{
    console.log(`服务启动成功:http://localhost:${APP_PORT}`);
})

4.app启动层

4.1app入口文件

javascript 复制代码

const {APP_PORT}=require("./config/config.default.js")
const app =require("./app/index.js")
app.listen(APP_PORT,()=>{
    console.log(`服务启动成功:http://localhost:${APP_PORT}`);
})

4.2app配置文件

javascript 复制代码

const koa = require("koa");
const bodyParser = require("koa-bodyparser");
const errHandle = require("./err.handle");
const userRouter = require("../router/users");

const app = new koa();

// 处理post参数解析中间件
app.use(bodyParser());
app.use(userRouter.routes()).use(userRouter.allowedMethods());

//错误处理
app.on("error", errHandle);
module.exports = app;

5.router路由层

5.1新增路由中间件

javascript 复制代码

const koa = require("koa");
const userRouter = require("../router/users");
const app = new koa();
app.use(userRouter.routes()).use(userRouter.allowedMethods());

5.2路由层配置

根据功能划分路由层

javascript 复制代码

const Router=require("koa-router")
const {userValidator,usernameValidator}=require("../../middlewares/users.middleware")
const router=new Router({prefix:"/users"})

const {regiest}=require("../../controller/users/index")

router.post("/regiest",userValidator,usernameValidator,regiest)


module.exports=router

6.controller业务控制层

处理对应路由的业务逻辑实现

6.1路由层注册controller层服务

javascript 复制代码

const Router=require("koa-router")
const {userValidator,usernameValidator}=require("../../middlewares/users.middleware")
const router=new Router({prefix:"/users"})
//这里注册业务层代码
const {regiest}=require("../../controller/users/index")

router.post("/regiest",userValidator,usernameValidator,regiest)


module.exports=router

6.2controller代码实现

javascript 复制代码

const { createUser } = require("../../service/user/index");
class UseController {
  //用户注册逻辑
  async regiest(ctx, next) {
    //获取前端传入结果
    const { user_name, password } = ctx.request.body;
    //操作数据库
    const res = await createUser(user_name, password);
    //返回给前端结果
    ctx.body = {
      code: 0,
      message: "用户注册成功",
      result: {
        id: res.id,
        user_name: res.user_name,
      },
    };
  }
}

module.exports = new UseController();

7.service服务层

7.1控制层注册服务层

下面的createUser方法来源于服务层

javascript 复制代码

const { createUser } = require("../../service/user/index");
class UseController {
  //注册逻辑
  async regiest(ctx, next) {
    //获取前端传入结果
    const { user_name, password } = ctx.request.body;
    //操作数据库,
    const res = await createUser(user_name, password);
    //返回给前端结果
    ctx.body = {
      code: 0,
      message: "用户注册成功",
      result: {
        id: res.id,
        user_name: res.user_name,
      },
    };
  }
}

module.exports = new UseController();

7.2服务层代码实现

javascript 复制代码

const User = require("../../model/users/index");

class UserService {
  //创建，使用async,数据库操作是异步的
  async createUser(user_name, password) {
    try {
      const res = await User.create({
        user_name,
        password,
      });
      return res.dataValues;
    } catch (error) {
      return error;
    }
  }
  // 根据任意字段查询
  async getUserInfo({id, user_name, password, is_admin}) {
    try {
      const whereOpt = {};
      id && Object.assign(whereOpt, { id });
      user_name && Object.assign(whereOpt, { user_name });
      password && Object.assign(whereOpt, { password });
      is_admin && Object.assign(whereOpt, { is_admin });
      console.log(whereOpt,'whereOpt');
      const res = await User.findOne({
        attributes: ["id", "user_name", "password", "is_admin"],
        where: whereOpt,
      });
      return res ? res.dataValues : null;
    } catch (error) {
      return error;
    }
  }
}

module.exports = new UserService();

8.DB数据层

8.1集成sequlize

官网 Sequelize 是一个基于 promise 的 Node.js ORM, 目前支持 Postgres, MySQL, MariaDB, SQLite 以及 Microsoft SQL Server. 它具有强大的事务支持, 关联关系, 预读和延迟加载,读取复制等功能。 Sequelize 遵从语义版本控制。支持 Node v10 及更高版本以便使用 ES6 功能。请通过 Getting started - 入门来学习更多相关内容. 如果你想要学习 Sequelize API 请通过 API 参考 (英文)。 ORM: 对象关系映射

数据表映射(对应)一个类
数据表中的数据行(记录)对应一个对象
数据表字段对应对象的属性
数据表的操作对应对象的方法

8.2安装mysql和 sequelize

javascript 复制代码

yarn add mysql2 sequelize

8.3连接mysql数据库

javascript 复制代码

const { Sequelize } = require("sequelize");
//连接数据库
const {
  MYSQL_HOST,
  MYSQL_PORT,
  MYSQL_USERNAME,
  MYSQL_PASSWORD,
  MYSQL_DB,
} = require("../config/config.default.js");
const seq = new Sequelize(MYSQL_DB, MYSQL_USERNAME, MYSQL_PASSWORD, {
  host: MYSQL_HOST,
  port: MYSQL_PORT,
  dialect: "mysql",

});
//检测数据库是否连接成功
seq
  .authenticate()
  .then((res) => {
    console.log("数据库连接成功");
  })
  .catch((err) => {
    console.log("数据库连接失败");
  });

module.exports = seq;

9.model模型层

9.1服务层注册模型层

9.2模型层代码实现，引入数据层

javascript 复制代码

const { Sequelize, DataTypes } = require("sequelize");
const seq = require("../../db/seq");

const User = seq.define(
  "iotUser",
  {
    // 在这里定义模型属性
    user_name: {
      type: DataTypes.STRING,
      unique: true,
      allowNull: false,
      comment: "用户名，唯一",
    },
    password: {
      type: DataTypes.CHAR(64),
      allowNull: false,
      comment: "密码",
    },
    is_admin: {
      type: DataTypes.BOOLEAN,
      allowNull: false,
      defaultValue: 0,
      comment: "是否是管理员,0不是,1是",
    },
  },
  {
    // 这是其他模型参数
    tableName: "iot_users",
  }
);

//如果数据库没有这张表会强制创建
User.sync();


module.exports=User

10.middlewares中间件层

10.1路由层引入

javascript 复制代码

const Router=require("koa-router")
const {userValidator,usernameValidator}=require("../../middlewares/users.middleware")
const router=new Router({prefix:"/users"})

const {regiest}=require("../../controller/users/index")

router.post("/regiest",userValidator,usernameValidator,regiest)


module.exports=router

10.2代码实现

javascript 复制代码

const { getUserInfo } = require("../service/user/index");
const { userFormateError, userAlreadyExit } = require("../constant/err.type");
const userValidator = async (ctx, next) => {
  const { user_name, password } = ctx.request.body;
  if (!user_name || !password) {
    ctx.app.emit("error", userFormateError, ctx);
    return;
  }
  await next();
};

const usernameValidator = async (ctx, next) => {
  const { user_name } = ctx.request.body;
  if (await getUserInfo({ user_name })) {
    ctx.app.emit("error", userAlreadyExit, ctx);
    return;
  }
  await next();
};
module.exports = {
  userValidator,
  usernameValidator,
};

10.3公共错误处理

定义错误类型字典

javascript 复制代码

module.exports = {
  userFormateError: {
    code: "1001",
    message: "用户名密码为空",
    result: [],
  },
  userAlreadyExit: {
    code: "1002",
    message: "用户已存在",
    result: [],
  },
};

错误映射表,映射状态码

javascript 复制代码

module.exports = (err, ctx) => {
  let status = 500;
  switch (err.code) {
    case "1001":
      status = 400;
      break;
    case "1002":
      status = 401;
      break;
    default:
      status = 500;
      break;
  }
  ctx.status=status;
  ctx.body=err
};

全局注册错误处理中间件

javascript 复制代码

const koa = require("koa");
const bodyParser = require("koa-bodyparser");
const errHandle = require("./err.handle");
const userRouter = require("../router/users");

const app = new koa();

// 处理post参数解析中间件
app.use(bodyParser());
app.use(userRouter.routes()).use(userRouter.allowedMethods());

//错误处理
app.on("error", errHandle);
module.exports = app;

用户已存在

koa结构化开发

1.1项目结构

1.2 babel环境配置

1.3webpack打包配置

1.4package.json配置

2.配置koa

2.1安装 Koa 框架

2.2 编写入口文件

2.3使用nodemon

2.4解析body参数

2.5解决跨域

2.6获取ip

3.config配置层

3.1根目录新建.env文件

3.2使用dotenv

4.app启动层

4.1app入口文件

4.2app配置文件

5.router路由层

5.1新增路由中间件

5.2路由层配置

6.controller业务控制层

6.1路由层注册controller层服务

6.2controller代码实现

7.service服务层

7.1控制层注册服务层

7.2服务层代码实现

8.DB数据层

8.1集成sequlize

8.2安装mysql和 sequelize

8.3连接mysql数据库

9.model模型层

9.1服务层注册模型层

9.2模型层代码实现，引入数据层

10.middlewares中间件层

10.1路由层引入

10.2代码实现

10.3公共错误处理