从零搭建koa + mongodb 项目

桃扇骨 2023-07-23 12:59 23阅读 0赞

###### 这是我第一个 koa 项目，第一次接触 koa, 基本靠百度解决问题，完全从零开始，也不知道会做到哪一步 ######

#### 1. `mkdir koa-server` ####

#### 2.`cd koa-server` ####

#### 3. `npm init -y` ####

#### 4. `npm install koa --save` ####

#### 5. 新建一个 app.js ####

const Koa = require('koa')
    
    const app = new Koa()
    
    app.use(async (ctx, next) => { 
        ctx.body = 'hello Koa'
    })
    
    app.listen(3000)

localhost:3000  
到此，最最基本的就搭好了

#### 6. `npm install koa-router --save` ####

app.js

const Koa = require('koa')
    const Router = require('koa-router')
    
    const app = new Koa()
    const router = new Router()
    
    app.use(async (ctx, next) => { 
        ctx.body = 'hello Koa'
        await next()
    })
    
    router.get('/test', async (ctx) => { 
        ctx.body = 'hello koa-router'
    })
    
    app.use(router.routes()).use(router.allowedMethods())
    
    app.listen(3000)

访问 localhost:3000/test 就可以看到 hello koa-router

#### 7.项目不可能所有的接口都放在主文件里面，所以在 routes 新建两个文件夹 user, news，里面新建两个文件 user/admin.js , news/list.js ####

app.js

const Koa = require('koa')
    const Router = require('koa-router')
    // 引入两个文件
    var admin = require('./routes/user/admin.js')
    var newList = require('./routes/news/list.js')
    
    const app = new Koa()
    const router = new Router()
    
    router.get('/', (ctx) => { 
        ctx.body = 'home page'
    })
    
    // 配置这两个,当你访问 /admin 这个路由是，会转发的 admin.js 文件下
    router.use('/admin', admin.routes())
    router.use('/news', newList.routes())
    
    app.use(router.routes()).use(router.allowedMethods())
    
    app.listen(3000)

routes/user/admin.js

const router = require('koa-router')()
    
    router.get('/user', (ctx) => { 
        ctx.body = 'admin'
    })
    
    module.exports = router

localhost:300/admin/user

这是最简单的 get 请求

###### 有的时候我们需要动态匹配路由 ######

const router = require('koa-router')()
    
    router.get('/user', (ctx) => { 
        ctx.body = 'admin'
    })
    
    router.get('/add/:id/:bid', async (ctx) => { 
        console.log(ctx.params)
        // { id: '112', bid: 'qwe' }
        ctx.body = '添加详情'
    })
    
    module.exports = router

localhost:3000/add/112/qwe

###### get 请求之后，就是 post 请求 `npm install koa-bodyparser --save` ######

app.js

const Koa = require('koa')
    const Router = require('koa-router')
    // 引入
    var bodyParser = require('koa-bodyparser')
    var admin = require('./routes/user/admin.js')
    var newList = require('./routes/news/list.js')
    
    const app = new Koa()
    const router = new Router()
    
    // 使用
    app.use(bodyParser())
    
    router.get('/', (ctx) => { 
        ctx.body = 'home page'
    })
    
    router.use('/admin', admin.routes())
    router.use('/news', newList.routes())
    
    app.use(router.routes()).use(router.allowedMethods())
    
    app.listen(3000)

routes/news/list.js

const router = require('koa-router')()
    
    router.get('/list', (ctx) => { 
        ctx.body = 'list'
    })
    
    router.post('/postRoute', async (ctx, next) => { 
        const rb = ctx.request.body
        console.log(rb);
        ctx.response.body = 'success'
    })
    
    module.exports = router

###### post 在浏览器的地址栏里面直接输入是不可以的，可以使用 postman 来进行测试，（主要是我没有使用静态模板，毕竟都前后端分离了。）但是使用postman进行post测试要注意一点，划重点了啊 ######

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDc3NzIx_size_16_color_FFFFFF_t_70_pic_center]

# **一定要记得这样选，不然你返回的就只有一个 \{\}** #

{  user: 'mjhgf', age: '111', sex: '0' }

#### 8. 身为后台,操作数据库是最基本的了，接下来就要进行对数据库的操作了。`npm install mongodb --save` ####

根目录下新建一个 utils 文件夹 ,里面放上 config.js ,db.js

config.js

const app = { 
        dbUrl: 'mongodb://localhost:27017',
        dbName: 'koa'
    }
    
    module.exports = app

db.js  
（对MongoDB的封装）

const MongoClient = require('mongodb').MongoClient
    
    const ObjectID = require('mongodb').ObjectID
    
    const Config = require('./config.js')
    
    // 封装
    
    class Db { 
    
        static getInstance () { 
            if (!Db.instance) { 
                Db.instance = new Db()
            }
            return Db.instance
        }
    
        constructor () { 
    
            this.dbClient = ''
            this.connect()
        }
    
        connect () { 
            return new Promise((resolve, reject) => { 
                if (!this.dbClient) { 
                    MongoClient.connect(Config.dbUrl, {  useUnifiedTopology: true }, (err, client) => { 
                        if (err) { 
                            reject(err)
                        } else { 
                            var db = client.db(Config.dbName)
                            this.dbClient = db
                            resolve(this.dbClient)
                        }
                    })
                } else { 
                    resolve(this.dbClient)
                }
            })
        }
    
        find (collectionName, json) { 
            return new Promise((resolve, reject) => { 
                this.connect().then(function (db) { 
                    var result = db.collection(collectionName).find(json)
                    result.toArray(function (err, docs) { 
                        if (err) { 
                            reject(err)
                            return
                        } else { 
                            resolve(docs)
                        }
                    })
                })
            })
        }
    
        update (collectionName, json1, json2) { 
            return new Promise((resolve, reject) => { 
                this.connect().then((db) => { 
                    db.collection(collectionName).updateOne(json1, { 
                        $set: json2
                    }, (err, result) => { 
                        if (err) { 
                            reject(err)
                            return
                        } else { 
                            resolve(result)
                        }
                    })
                })
            })
        }
    
        insert (collectionName, json) { 
            return new Promise((resolve, reject) => { 
                this.connect().then((db) => { 
                    db.collection(collectionName).insertOne(json, function (err, result) { 
                        if (err) { 
                            reject(err)
                            return
                        } else { 
                            resolve(result)
                        }
                    })
                })
            })
        }
    
        remove (collectionName, json) { 
            return new Promise((resolve, reject) => { 
                this.connect().then((db) => { 
                    db.collection(collectionName).removeOne(json, function (err, result) { 
                        if (err) { 
                            reject(err)
                            return
                        } else { 
                            resolve(result)
                        }
                    })
                })
            })
        }
    
        // 查询 _id
        gteObjectID (id) { 
            return new ObjectID(id)
        }
    }
    
    module.exports = Db.getInstance()

routes/user/admin.js  
(你得提前连接自己的数据库，在数据库里面新建一个 koa 数据库 里面新建一个 user 表)

const router = require('koa-router')()
    const DB = require('../../utils/db.js')
    
    router.get('/user', async (ctx) => { 
        var result = await DB.find('user', { })
        ctx.body = result
    })
    
    module.exports = router

这样就可以使用 koa 操作数据库了。

#### 9.对数据库增删改查 ####

routes/user/admin.js

const router = require('koa-router')()
    const DB = require('../../utils/db.js')
    
    router.get('/add/:id/:bid', async (ctx) => { 
        // http://localhost:3000/add/112/qwe
        console.log(ctx.params)
        // { id: '112', bid: 'qwe' }
        ctx.body = '添加详情'
    })
    
    // 查询
    router.get('/list', async (ctx) => { 
        var result = await DB.find('user', { })
        ctx.body = result
    })
    
    // 插入
    router.post('/doAdd', async (ctx) => { 
        let data = await DB.insert('user', ctx.request.body)
        ctx.body = data
        try { 
            if (data.result.ok) { 
                console.log(ctx.body)
            }
        } catch (error) { 
            console.log(err)
            ctx.redirect('/')
        }
    })
    
    // 删除
    router.get('/remove', async (ctx) => { 
        // let user = ctx.query.user
        let user = ctx.request.body.user
        console.log(user)
        var data = await DB.remove('user', { 'user': user})
        try { 
            if (data.result.ok) { 
                // ctx.redirect('/')
                ctx.body = data
            }
        } catch (error) { 
            console.log(err)
        }
    })
    
    // 更新
    router.get('/update', async (ctx) => { 
        var id = ctx.query.id
        var user = ctx.query.user
        var age = ctx.query.age
        var sex = ctx.query.sex
    
        console.log(DB.getObjectID(id), user, age, sex)
    
        let data = await DB.update('user', { '_id': DB.getObjectID(id)}, { 
            age,
            sex
        })
    
        try { 
            if (data.result.ok) { 
                ctx.body = data
            }
        } catch (error) { 
            console.log(err)
            ctx.redirect('/add')
        }
    })
    
    
    module.exports = router

###### 基本的数据库操作就到这里了。 ######

#### 10.登录和注册功能 ####

新建一个 login.js

const router = require('koa-router')()
    const DB = require('../../utils/db.js')
    
    router.post('/register', async (ctx) => { 
        let data = await DB.insert('author', ctx.request.body)
        console.log(data)
        ctx.body = data
        try { 
            if (data.result.ok) { 
                ctx.redirect('/login/getInfo')
            }
        } catch (error) { 
            console.log(error)
            // ctx.redirect('/')
        }
    })
    
    router.post('/login', async (ctx) => { 
        let name = ctx.request.body.name
        let email = ctx.request.body.email
        let pwd = ctx.request.body.pwd
    
        console.log(name, email, pwd)
        var result = await DB.find('author',
        { 'name': name, 'email': email, 'pwd': pwd})
    
        console.log(result)
        try { 
            if (result.length > 0) { 
                ctx.body = '登录成功'
                ctx.redirect('/')
            }
        } catch (error) { 
            console.log(error)
            // ctx.redirect('/')
        }
    })
    
    router.get('/getInfo', async (ctx) => { 
        var result = await DB.find('author', { })
        ctx.body = result
    })
    
    module.exports = router

#### 11. 利用 JWT 设置 Token ####

const Koa = require('koa')
    const Router = require('koa-router')
    const bodyParser = require('koa-bodyparser')
    const jwt = require('jsonwebtoken')
    const jwtKoa = require('koa-jwt')
    
    var admin = require('./routes/user/admin.js')
    var newList = require('./routes/news/list.js')
    var login = require('./routes/user/login.js')
    const DB = require('./utils/db.js')
    const keys = require('./utils/config')
    
    const app = new Koa()
    const router = new Router()
    
    const secret = 'secret'
    
    app.use(jwtKoa({ secret}).unless({ 
        path: [/\/register/, /\/login/]
    }))
    
    app.use(bodyParser())
    
    app.use(async (ctx, next) => { 
        console.log(ctx)
        let params =Object.assign({ }, ctx.request.query, ctx.request.body);
        ctx.request.header = { 'authorization': "Bearer " + (params.token || '')}
        await next();
    })
    
    router.get('/', async (ctx) => { 
        ctx.body = 'home'
    })
    
    router.post('/register', async (ctx) => { 
    
        console.log(ctx.request.body.email)
        let email = ctx.request.body.email
    
        const findResult = await DB.find('author', { 
            'email': email
        })
    
        console.log(findResult)
    
        if (findResult.length > 0) { 
            ctx.status = 506
            ctx.body = {  email: '邮箱已被占用 ' }
        } else { 
            let data = await DB.insert('author', ctx.request.body)
            console.log(data)
            ctx.body = data
            try { 
                if (data.result.ok) { 
                    ctx.body = { 
                        mssage: '注册成功'
                    }
                }
            } catch (error) { 
                console.log(error)
                // ctx.redirect('/')
            }
        }
    })
    
    router.post('/login', async (ctx, next) => { 
        let name = ctx.request.body.name
        let email = ctx.request.body.email
        let pwd = ctx.request.body.pwd
    
        console.log(name, email, pwd)
    
        var result = await DB.find('author',
        { 'name': name, 'email': email})
    
        console.log(result)
    
        if (result.length === 0) { 
            ctx.status = 404
            ctx.body = {  email: '用户不存在!' }
        } else { 
            var result = await DB.find('author',{ 'pwd': pwd})
            if (result) { 
                // 返回token
                const payload = {  pwd: pwd, name: name}
                const token = jwt.sign(payload, keys.secretOrkey, {  expiresIn: 3600 })
    
                ctx.status = 200
                ctx.body = {  success: true, token: 'Bearer ' + token }
            } else { 
                ctx.status = 400
                ctx.body = {  password: '密码错误!' }
            }
        }
    })
    
    router.use('/admin', admin.routes())
    router.use('/news', newList.routes())
    router.use('/login', login.routes())
    
    app.use(router.routes()).use(router.allowedMethods())
    
    app.listen(3000)

#### [项目地址][Link 1] ####

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQzNDc3NzIx_size_16_color_FFFFFF_t_70_pic_center]: /images/20230528/9a6b881cbd434d698148158283897589.png
[Link 1]: https://gitee.com/suiboyu/koa-server