Weather Metrics

Overview

This is API that will retrieve weather metrics of a specific city. We are using Open Weather Map API for collecting Weather forecast data. Refer here for more details.

Steps to Setup and Run

1. Clone the repository

git clone https://github.com/rajeshdave/WeatherMetrics.git

2. How to Run

You may package the application in the form of a jar and then run the jar file like so -

mvn clean package
java -jar target/WeatherMetrics-0.0.1-SNAPSHOT.jar

That's it! The application can be accessed at http://localhost:4000/weather?city=London,uk.

Weather Metrics Details

We are using Open Weather Forecast API to retrieve forecast data and generate below metrics:

• Average of daily (06:00 – 18:00) and nightly (18:00 – 06:00) temperatures in Celsius for the next 3 days from today’s date.
• Average of pressure for the next 3 days from today’s date.

The endpoint must include a CITY parameter containing the city’s name as the input for the correct response.

• For example, http://localhost:4000/weather?city=London,uk will return below output:

{
  "perDayMetrics": {
    "2019-03-03": {
      "NightTemperature": 10.03,
      "DayTemperature": 11.935,
      "Pressure": 994.8199999999999
    },
    "2019-03-04": {
      "NightTemperature": 6.835,
      "DayTemperature": 6.5,
      "Pressure": 992.3575
    },
    "2019-03-05": {
      "NightTemperature": 5.109999999999999,
      "DayTemperature": 6.215,
      "Pressure": 999.41
    }
  }
}

We will be hitting below URL, which is returning data for every 3 hours. URL: http://api.openweathermap.org/data/2.5/forecast?q=London,uk&units=metric&cnt=24&APPID=4d8d9da673e70c41ef740081db5e4a10 We are passing 'cnt=24' to collect next 3 days records. In case, we are getting data of fourth day then we are just ignoring same.

Code and Testcase Details

This is Spring boot application using Spring Boot v2.1.3.RELEASE and Spring v5.1.5.RELEASE.

• WeatherMetricsApplication.java is Spring boot application class.
• OpenWeatherController is REST controller to handle all requests.
• WeatherMetricsService is responsible for building weather metrics by using data from WeatherDataService.
• WeatherDataService is to make REST call to collect forecast data.
• ExceptionHandlerController is for handling all exceptions. WeatherMetricsNotFoundException is custom exception.

Below are test cases added to test the code:

• WeatherMetricsApplicationTests for doing end to end integration tests. This cover testcases for both successful and exception scenarios.
• OpenWeatherMetricsServiceTest is added to do unit testing of Metrics logic by mocking forecast data response.

Motivations

Below are motivations behind given design of application:

• Clean code
• Single Responsibility by layered design. Like OpenWeatherController, WeatherMetricsService, WeatherDataService etc.
• Isolation by use of Interfaces.
• Global Exception handling with REST standard error response.
• Unit and integration Test cases with nearly 100% Code coverage.
• No issue based on Sonar analysis.
• For more details please refer javadoc of each class.

“It is not enough for code to work.” ― Robert C. Martin, Clean Code: A Handbook of Agile Software Craftsmanship