Five Day Forecast App

Service to get five-day weather forecast for every main polish administrative area (voivodeship).

Workshop application to practice reactive approach to REST service.

Technologies
How to run
Features
Sidenotes

Technologies

Project created with:

Java 1.8
Spring Boot 2.4.0

Tests framework and tools:

Spock 1.3
MockWebServer 3.14
WireMock 2.27

How to run

To run this project type command:

If maven is installed:
- mvn spring-boot:run
If not, use maven wrapper:
- linux: /mvnw spring-boot:run
- windows: /mvnw.cmd spring-boot:run

Features

Application provides REST Api in terms of:

Providing weather forecast

By using polish postal code as a location reference, service matches it with a voivodeship and provides weather forecast for next five days. Weather data is gathered from Accuweather.

endpoint: /forecasts/voivodeships/5day/{postalCode}
response body model:

{
  "dailyForecast": [
    {
      "date": "2020-11-26",
      "temperature": {
        "max": 0,
        "min": 0,
        "unit": "C"
      }
    },
    {
      "date": "2020-11-27",
      "temperature": {
        "max": 0,
        "min": 0,
        "unit": "C"
      }
    }
  ]
}

As daily Accuweather forecasts are refreshed every 4 hours, application stores data from previous requests. Queried postal codes are bonded to voivodeships, and when forecast response from Accuweather is received it's stored together with related voivodeships.

Application runs scheduled weather forecasts updates, so it minimizes response time and number of calls to third party service. Also after each update service saves repository snapshot file. After reboot, it uses this file to restore already collected data.

Providing number of requests send to Accuweather

Application tracks number of requests to Accuweather.

requests are divided to:
- location request - to get weather forecast from Accuweather you need to obtain location key first. Location key can be found by city name, geographic coordinates or postal code.
- forecast request - calls for weather forecast for previously received location key

Rebooting application resets counter.

endpoint: /statistics/requests/accuweather
response body model:

{
  "locationCalls": 0,
  "weatherCalls": 0,
  "total": 0
}

Sidenotes

Application provides swagger-ui for endpoint representation. By default, when running locally go to this url to access swagger: localhost:8080/swagger-ui/
By default, application starts empty repository. However, You can find snapshot file HERE. To put this into repository, just change file name to correspond with forecast.repository.snapshot.path parameter in forecast.properties file and start application
First call for weather forecast is always very slow. The reason for this is that Spring WebClient uses Netty for non-blocking requests. Unfortunately, it comes with this minor drawback which is caused by lazy initialization of Netty context. For explanation go HERE. This problem occurs only by first call. Consecutive requests work without any delay.

bierzan/forecast-client