Problem

Read earthquake events from https://earthquake.usgs.gov/earthquakes/feed/v1.0/summary/all_month.geojson and find 10 earthquakes that happened in the closest proximity to the input location.

In detail, create a (REST) microservice that:

• Accepts two float numbers as request parameters that represent the lat/lon of any location
• Read a list of earthquakes that happened during last 30 days
• Calculate distance between given location and each of the earthquakes
• Provide a JSON response and also print the 10 earthquakes with the shortest distance to the given location
• The output list should contain earthquake magnitude, title, date, distance in kilometers and geographic coordinates
• If there is more than one earthquake event recorded in any location, there should be only one considered

Solution

Technology stack

Spring Boot, Java 8+, WebFlux

How to run

There are two ways to run the app

From Intellij IDEA

Open the downloaded source code in Intellij IDEA, and run the EarthquakesApplication.java

Run the jar

Download the earthquakes/target/earthquakes-service.jar and run in the terminal

java -jar earthquakes-service.jar 

Where to see the output

There are currently two solutions provided: synchronous with blocking and asynchronous.

After the application is started, it is mandatory to open a browser and pass the latitude and longitude as part of the URL endpoint

Synchronous solution URI:

http://localhost:8081/api/earthquake/lat/{lat}/lon/{lon}

Asynchronous solution URI:

http://localhost:8081/api/earthquake/async/lat/{lat}/lon/{lon}

The output is available as a JSON response and in the console (if run from the Intellij IDEA) and in the terminal (if run through the terminal command)

NOTE: The instructions are tested on MacOS