disneyAppBackend

Spring Boot backend for the Park Day Diary Expo app (disneyapp-frontend). It proxies and caches two free public APIs so all clients share the same upstream calls:

Endpoint	Upstream	Purpose
GET /api/wait-times/{park}	queue-times.com	Live ride wait times. {park} is disneyland or california-adventure.
GET /api/weather	open-meteo.com	Current weather for Anaheim, CA.
GET /actuator/health	—	Liveness check.

Why a backend at all?

The frontend used to call queue-times and open-meteo directly from the device. Moving those calls server-side gives us:

1. Shared cache. One server-side fetch serves every app instance — fewer upstream calls, faster responses, polite to free APIs.
2. Decoupling. If queue-times changes its schema or we swap weather providers, only the backend changes — no app store release needed.
3. A place to grow. Trip storage, push notifications when a favorite ride drops below 15 min, recommendations — all need a backend.

Stack

• Java 21
• Spring Boot 3.5
• Spring Web (REST) + RestClient (outbound HTTP)
• Spring Cache abstraction backed by Caffeine (in-memory, per-cache TTL)
• Spring Boot Actuator (health check)

Data sources & attribution

This service is a thin, caching proxy in front of two generous free APIs. Both ask for credit, which this project gives in the frontend UI and below:

• Wait times — Powered by Queue-Times.com. Used per their Real Time API terms: access is free, attribution is required.
• Weather — Powered by Open-Meteo.com, licensed under CC-BY 4.0.

Please respect both providers' rate limits if you fork this — the Caffeine caches and the 5-minute notification poll interval are sized to be polite, not just fast.

Project layout

src/main/java/com/disneyapp/backend/
├── DisneyAppBackendApplication.java   # entry point, @EnableCaching
├── config/
│   ├── CacheConfig.java               # two Caffeine caches with TTLs
│   ├── HttpClientConfig.java          # one RestClient bean per upstream
│   ├── WebConfig.java                 # CORS for the Expo web build
│   └── GlobalExceptionHandler.java    # uniform JSON error responses
├── waittimes/
│   ├── WaitTimesController.java       # GET /api/wait-times/{park}
│   ├── WaitTimesService.java          # fetch + map + @Cacheable
│   ├── ParkId.java                    # enum: DISNEYLAND, CALIFORNIA_ADVENTURE
│   └── dto/                           # LiveRide, LiveLand, WaitTimesResponse, QueueTimesRaw
└── weather/
    ├── WeatherController.java         # GET /api/weather
    ├── WeatherService.java
    └── dto/                           # CurrentWeather, OpenMeteoRaw

src/main/resources/application.yml     # port, TTLs, CORS origins, base URLs

Prerequisites

• Java 21. On macOS:

  brew install openjdk@21
  sudo ln -sfn /opt/homebrew/opt/openjdk@21/libexec/openjdk.jdk \
    /Library/Java/JavaVirtualMachines/openjdk-21.jdk

  Verify with java -version.

You don't need Maven installed — the project ships with ./mvnw, which downloads the right Maven version on first run.

Run it

./mvnw spring-boot:run

The server binds to http://localhost:8080. Try:

curl http://localhost:8080/api/weather | jq
curl http://localhost:8080/api/wait-times/disneyland | jq
curl http://localhost:8080/api/wait-times/california-adventure | jq
curl http://localhost:8080/actuator/health

The first call to each endpoint hits the upstream API; subsequent calls within the TTL are served instantly from the Caffeine cache. Watch the logs — you'll see Cache miss — fetching ... only when the cache expires.

Configuration

Everything tunable lives in src/main/resources/application.yml:

server:
  port: 8080

cache:
  wait-times-ttl-seconds: 60     # queue-times updates every ~5 min anyway
  weather-ttl-seconds: 300       # weather changes slowly

cors:
  allowed-origins:
    - http://localhost:8081      # Expo Metro web
    - http://localhost:19006     # legacy Expo web
    - http://localhost:3000

You can override any property at runtime with an env var, e.g. SERVER_PORT=9000 ./mvnw spring-boot:run.

Connecting the frontend

The Expo app reads its backend base URL from expo.extra.apiBaseUrl in disneyAppFrontend/my-app/app.json (defaults to http://localhost:8080).

• iOS Simulator: localhost works as-is.
• Android Emulator: handled automatically — lib/api.ts rewrites localhost to 10.0.2.2 (the emulator's alias for the host machine).
• Physical device: set EXPO_PUBLIC_API_BASE_URL=http://<your-mac-lan-ip>:8080 before running expo start, and make sure the device is on the same Wi-Fi.

Build a production jar

./mvnw clean package
java -jar target/backend-0.0.1-SNAPSHOT.jar

The resulting jar is fully self-contained (embedded Tomcat included) and can be deployed to any host with a JDK 21+ runtime, or built into a container.