MongoDB Atlas で回復力のあるアプリケーションを構築

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// File: App.java
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import java.util.Map;
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import java.util.logging.Logger;
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import org.bson.Document;
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import org.json.JSONArray;
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import com.mongodb.MongoException;
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import com.mongodb.client.MongoClient;
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import com.mongodb.client.MongoClients;
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import com.mongodb.client.MongoCollection;
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import com.mongodb.client.MongoDatabase;
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import fi.iki.elonen.NanoHTTPD;
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public class App extends NanoHTTPD {
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    private static final Logger LOGGER = Logger.getLogger(App.class.getName());
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    static int port = 3000;
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    static MongoClient client = null;
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    public App() throws Exception {
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        super(port);
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        // Replace the uri string with your MongoDB deployment's connection string
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        String uri = "<atlas-connection-string>";
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        client = MongoClients.create(uri);
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        start(NanoHTTPD.SOCKET_READ_TIMEOUT, false);
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        LOGGER.info("\nStarted the server: http://localhost:" + port + "/ \n");
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    }
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    public static void main(String[] args) {
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        try {
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            new App();
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        } catch (Exception e) {
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            LOGGER.severe("Couldn't start server:\n" + e);
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        }
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    }
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    @Override
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    public Response serve(IHTTPSession session) {
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        StringBuilder msg = new StringBuilder();
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        Map<String, String> params = session.getParms();
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        Method reqMethod = session.getMethod();
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        String uri = session.getUri();
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        if (Method.GET == reqMethod) {
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            if (uri.equals("/")) {
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                msg.append("Welcome to my API!");
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            } else if (uri.equals("/users")) {
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                msg.append(listUsers(client));
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            } else {
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                msg.append("Unrecognized URI: ").append(uri);
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            }
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        } else if (Method.POST == reqMethod) {
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            try {
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                String name = params.get("name");
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                if (name == null) {
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                    throw new Exception("Unable to process POST request: 'name' parameter required");
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                } else {
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                    insertUser(client, name);
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                    msg.append("User successfully added!");
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                }
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            } catch (Exception e) {
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                msg.append(e);
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            }
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        }
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        return newFixedLengthResponse(msg.toString());
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    }
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    static String listUsers(MongoClient client) {
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        MongoDatabase database = client.getDatabase("test");
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        MongoCollection<Document> collection = database.getCollection("users");
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        final JSONArray jsonResults = new JSONArray();
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        collection.find().forEach((result) -> jsonResults.put(result.toJson()));
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        return jsonResults.toString();
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    }
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    static String insertUser(MongoClient client, String name) throws MongoException {
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        MongoDatabase database = client.getDatabase("test");
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        MongoCollection<Document> collection = database.getCollection("users");
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        collection.insertOne(new Document().append("name", name));
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        return "Successfully inserted user: " + name;
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    }
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}

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const express = require('express');
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const bodyParser = require('body-parser');
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// Use the latest drivers by installing & importing them
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const MongoClient = require('mongodb').MongoClient;
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const app = express();
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app.use(bodyParser.json());
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app.use(bodyParser.urlencoded({ extended: true }));
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const uri = "mongodb+srv://<db_username>:<db_password>@cluster0-111xx.mongodb.net/test?retryWrites=true&w=majority";
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const client = new MongoClient(uri, {
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    useNewUrlParser: true,
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    useUnifiedTopology: true
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});
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// ----- API routes ----- //
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app.get('/', (req, res) => res.send('Welcome to my API!'));
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app.get('/users', (req, res) => {
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    const collection = client.db("test").collection("users");
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    collection
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    .find({})
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    .maxTimeMS(5000)
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    .toArray((err, data) => {
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        if (err) {
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            res.send("The request has timed out. Please check your connection and try again.");
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        }
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        return res.json(data);
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    });
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});
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app.post('/users', (req, res) => {
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    const collection = client.db("test").collection("users");
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    collection.insertOne({ name: req.body.name })
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    .then(result => {
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        res.send("User successfully added!");
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    }, err => {
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        res.send("An application error has occurred. Please try again.");
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    })
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});
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// ----- End of API routes ----- //
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app.listen(3000, () => {
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    console.log(`Listening on port 3000.`);
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    client.connect(err => {
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        if (err) {
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            console.log("Not connected: ", err);
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            process.exit(0);
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        }
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        console.log('Connected.');
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    });
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});

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# File: main.py
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from fastapi import FastAPI, Body, Request, Response, HTTPException, status
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from fastapi.encoders import jsonable_encoder
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from typing import List
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from models import User
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import pymongo
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from pymongo import MongoClient
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from pymongo import errors
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# Replace the uri string with your |service| connection string
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uri = "<atlas-connection-string>"
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db = "test"
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app = FastAPI()
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@app.on_event("startup")
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def startup_db_client():
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    app.mongodb_client = MongoClient(uri)
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    app.database = app.mongodb_client[db]
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@app.on_event("shutdown")
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def shutdown_db_client():
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    app.mongodb_client.close()
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##### API ROUTES #####
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@app.get("/users", response_description="List all users", response_model=List[User])
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def list_users(request: Request):
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    try:
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        users = list(request.app.database["users"].find().max_time_ms(5000))
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        return users
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    except pymongo.errors.ExecutionTimeout:
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        raise HTTPException(status_code=status.HTTP_503_SERVICE_UNAVAILABLE, detail="The request has timed out. Please check your connection and try again.")
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@app.post("/users", response_description="Create a new user", status_code=status.HTTP_201_CREATED)
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def new_user(request: Request, user: User = Body(...)):
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    user = jsonable_encoder(user)
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    try:
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        new_user = request.app.database["users"].insert_one(user)
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        return {"message":"User successfully added!"}
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    except pymongo.errors.DuplicateKeyError:
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        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="Could not create user due to existing '_id' value in the collection. Try again with a different '_id' value.")