Koa2脚手架框架搭建流程

Koa2脚手架框架搭建流程


记录一下自己之前使用koa2创建项目时初始化的整个流程:
  • 路由
  • 数据库
  • 返回结构定义
  • 封装DBError
  • Token

路由

  • 定义在app.js中
const api = require('./routes/api/index');

router.use('/api', api.routes(), api.allowedMethods());
app.use(router.routes(), router.allowedMethods());
router.post('/updateUser', token_valide,user_controller.updateUser);//这里token_valide是路由中间件,按顺序执行
  • index.js
var router = require('koa-router')();
var user_router = require('./user_router');

router.use('/users', user_router.routes(), user_router.allowedMethods());

module.exports = router;


数据库

  • 使用sequelize操作mysql,用以下命令自动生成操作需要的模块
sequelize-auto -o "./schema" -d appstore -h 111.111.11.102 -u root -p 3306 -x root -e mysql
  • db.js
const Sequelize = require('sequelize')
const config = {
    database: '',
    username: '',
    password: '',
    host: '',
    port: 3306
}
const DATABASE = new Sequelize(config.database, config.username, config.password, {
    host: config.host,
    dialect: 'mysql', // 数据库方言
    pool: {
        max: 5,
        min: 0,
        idle: 30000
    },
    define: {
        timestamps: false
    }
})

module.exports = {
    DATABASE
}
  • 数据库操作类封装
/**
 * Created by lipeng on 17/8/6.
 */
// models/user.js
const db = require('../config/db')
const DATABASE = db.DATABASE // 引入数据库
const User = DATABASE.import("../schema/user.js"); // 用sequelize的import方法引入表结构,实例化了User。
const ResponseCodes = require('../util/ResponseCodes')
const DBError = require('./dberror');

class UserTable {
    // 数据库操作
    static queryAll() {
        return User.findAll();
    }

    /**
     * 查询用户信息
     * @param name  姓名
     * @returns {Promise.<*>}
     */
    static async findUserByName (username) {
        try {
            const userInfo = await User.findOne({
                where: {
                    username
                }
            })
            return userInfo ;
        }catch(err) {
           throw new DBError(ResponseCodes.DBERROR,err);
        }
    }

    /**
     * 创建用户
     * @param user
     * @returns {Promise.}
     */
    static async createUser (user) {
        try {
            let rows = await User.create(user)
            return {"rows":rows};
        }catch(err) {
            throw new DBError(ResponseCodes.DBERROR,err);
        }
    }
}

module.exports = UserTable;



返回结构定义

  1. 数据库操作错误封装,抛出异常

    static async findUserByName (username) {
        try {
            const userInfo = await User.findOne({
                where: {
                    username
                }
            })
            return userInfo ;
        }catch(err) {
           throw new DBError(ResponseCodes.DBERROR,err);
        }
    }
  • 封装的DBError
class DBError extends Error{
    //构造方法
    constructor(code,error){
        super();

        this.error = error;
        this.code = code;
    }
}
module.exports = DBError;
  • 中间件统一处理数据库异常
/**
 * Created by lipeng on 17/8/7.
 */
const DBError = require('../models/dberror');

/**
 * 在app.use(router)之前调用
 */
var dberror_response = async (ctx, next) => {
    //先去执行路由
    try {
        //先去执行路由
        await next();
    } catch (error) {
        if(error instanceof DBError){
            ctx.status = 200;
            ctx.error(error.code,error.error);
        }
        //继续抛,让外层中间件处理日志
        throw error;
    }
}

module.exports = dberror_response;
  1. 网络请求返回封装
  • 中间件封装一层 response
app.use(response);
var ResponseCodes = require('../util/ResponseCodes');
module.exports = async (ctx, next) => {
    ctx.error = ( code,  msg,data) => {
        if(!msg){
            msg = ResponseCodes.getErrorInfo(code);
        }
       ctx.body = { code: code, msg:msg, data:data};
    }
    ctx.success = (data) => {
        ctx.body = { errno: 0, msg:"success", data:data };
    }
    await next()
}
  • 定义ResponseCodes,这里只定义错误code,正确的默认是0
/**
 * Created by lipeng on 17/8/6.
 */
/**
 * API错误名称
 */
var ResponseCodes = {};

ResponseCodes.UNKNOW_ERROR = "-1";
ResponseCodes.USER_NOT_EXIST = "-2";

ResponseCodes.USER_EXIST = "-3";
ResponseCodes.DBERROR = "-4";
/**
 * API错误名称对应的错误信息
 */
const error_map = new Map();

error_map.set(ResponseCodes.UNKNOW_ERROR,  '未知错误');
error_map.set(ResponseCodes.USER_NOT_EXIST,  '用户不存在');
error_map.set(ResponseCodes.USER_EXIST,  '用户名已存在');
error_map.set(ResponseCodes.DBERROR,  '数据库连接错误');

//根据错误名称获取错误信息
ResponseCodes.getErrorInfo = (error_name) => {

    var error_info;

    if (error_name) {
        error_info = error_map.get(error_name);
    }

    //如果没有对应的错误信息,默认'未知错误'
    if (!error_info) {
        error_name = UNKNOW_ERROR;
        error_info = error_map.get(error_name);
    }

    return error_info;
}

module.exports = ResponseCodes;

Token

  • 引入两个库
const bcrypt = require('bcryptjs')
const jwt = require('jsonwebtoken')
  • 生成token
    /**
     * 登录
     * @param ctx
     * @param next
     * @returns {Promise.}
     */
    static async loginUser (ctx,next) {
        let body = ctx.request.body;
        //判断是否用户名已经存在
        let user = await UserTable.findUserByName(body.username);

        if(user){
            // 判断前端传递的用户密码是否与数据库密码一致
            if (bcrypt.compareSync(body.password, user.password)) {

                // 用户token
                const userToken = {
                    username: user.username,
                    id: user.id
                }
                const token = jwt.sign(userToken, secret.sign, {expiresIn: '1h'})  // 签发token
                user.token = token;
                ctx.success(user)
            }else{
                ctx.error(ResponseCodes.LOGIN_ERROR);
            }
        }else{
            ctx.error(ResponseCodes.LOGIN_ERROR);
        }

    }
  • 请使用expiresIn:以秒为单位或描述的时间跨度字符串表示rauchg / MS。如:60,”2 days”,”10h”,”7d”


{expiresIn: 60}       // 有效期60秒(没有时间单位以秒为准)
  {expiresIn: "2 days"}   // 有效期 2天 (后缀为时间单位)下面的类似
  ...... 
     ('1d')      // 86400000
     ('10h')     // 36000000
     ('2.5 hrs') // 9000000
     ('2h')      // 7200000
     ('1m')      // 60000
     ('5s')      // 5000
     ('1y')      // 31557600000
  • verify时返回的err的值

"err": {
    "name": "TokenExpiredError",
    "message": "jwt expired",   //  token过了有效期
    "expiredAt": "2016-11-07T03:31:25.000Z"
  }

 "err": {
    "name": "JsonWebTokenError",
    "message": "invalid token"  //  伪造/无效的token
  }
  • Token处理中间件
/**
 * Created by lipeng on 17/8/7.
 */
var jwt = require('jsonwebtoken');//用来创建和确认用户信息摘要
const secret = require('../config/secret.json')
const ResponseCodes = require('../util/ResponseCodes')
const DBError = require('../models/dberror');

function verify(token) {
    return new Promise(( resolve, reject ) => {
        jwt.verify(token, secret.sign, async function (err, decode) {
            if (err) {  //  时间失效的时候/ 伪造的token
                resolve(new DBError(ResponseCodes.TOKEN_ERROR, err)) ;
            } else {
                console.log("decode.msg:" + JSON.stringify(decode));   // today  is  a  good  day
                resolve(decode)
            }
        })
    })
}

// 检查用户会话
module.exports = async (ctx, next) => {
    console.log('检查post的信息或者url查询参数或者头信息');
    let body = ctx.request.body;
    var token =  body.token || ctx.query.token || ctx.request.headers['x-access-token']; // 从body或query或者header中获取token
    // 解析 token
    if (token) {
        let result = await verify(token);
        if(result instanceof DBError){
            throw result;
        }else{
            body.userToken = result;
            await next();
        }
    }else{
        throw new DBError(ResponseCodes.TOKEN_ERROR);
    }

}


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