92 lines
1.8 KiB
JavaScript
92 lines
1.8 KiB
JavaScript
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/**
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* Webservice mit Express
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* WBE-Praktikum
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*/
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var express = require('express')
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var app = express()
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// Fehlerobjekt anlegen
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//
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function error(status, msg) {
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var err = new Error(msg)
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err.status = status
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return err
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}
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// Zufällige ID erzeugen, Quelle:
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// https://stackoverflow.com/questions/6860853/generate-random-string-for-div-id#6860916
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//
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function guidGenerator() {
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var S4 = function() {
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return (((1+Math.random())*0x10000)|0).toString(16).substring(1)
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}
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return (S4()+S4()+"-"+S4()+"-"+S4()+"-"+S4()+"-"+S4()+S4()+S4())
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}
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// API-Key überprüfen
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//
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app.use('/api', function(req, res, next){
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var key = req.query['api-key']
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// Key fehlt
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if (!key) {
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return next(error(400, 'api key required'))
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}
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// Key falsch
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if (!~apiKeys.indexOf(key)) {
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return next(error(401, 'invalid api key'))
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}
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// korrekter Key
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req.key = key
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next()
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})
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// JSON-Daten akzeptieren
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app.use(express.json())
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// gültige API-Keys
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var apiKeys = ['wbeweb']
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// unsere tolle in-memory Datenbank :)
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var data = {1234567890: {demodata: "wbe is an inspiring challenge"}}
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// GET-Request bearbeiten
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//
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app.get('/api/data/:id', function(req, res, next){
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var id = req.params.id
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var result = data[id]
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if (result) res.send(result)
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else next()
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})
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// POST-Request bearbeiten
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//
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app.post('/api/data', function (req, res, next) {
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let id = guidGenerator()
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data[id] = req.body
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res.send({id})
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})
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// Middleware mit vier Argumenten wird zur Fehlerbehandlung verwendet
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//
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app.use(function(err, req, res, next){
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res.status(err.status || 500)
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res.send({ error: err.message })
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})
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// Catch-all: wenn keine vorangehende Middleware geantwortet hat, wird
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// hier ein 404 (not found) erzeugt
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//
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app.use(function(req, res){
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res.status(404)
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res.send({ error: "not found" })
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})
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app.listen(3000)
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console.log('Express started on port 3000')
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