tphiep / exercise

exercise

exercise

This is a simple project to implement REST APIs for storing and reading device data.

System prerequisites

1. Java 11
2. Maven 3
3. Docker (Docker Compose)

Build

1. At project root run: mvn clean package -DskipTests=true docker:build
2. Start all services: docker-compose up (it will take about 2 minutes for all services up and running)
3. Build e2e test: mvn clean package

Service endpoints

• POST

curl -d '{"deviceId": "e3d4686d-5d2a-42c7-a471-1efb761646d4", "latitude": 41.25, "longitude": -120.9762, "data": {"humidity": 123, "temperature": {"unit": "C", "value": "23.3"}}}' -H "Content-Type: application/json" -X POST http://localhost:8089/api/devices
{"deviceId":"e3d4686d-5d2a-42c7-a471-1efb761646d4","timestamp":"2022-04-17T04:53:01.410Z"}
curl -d '{"deviceId": "e3d4686d-5d2a-42c7-a471-1efb761646d4", "latitude": 41.25, "longitude": -120.9762, "data": {"humidity": 123, "temperature": {"unit": "F", "value": "223.3"}}}' -H "Content-Type: application/json" -X POST http://localhost:8089/api/devices
{"deviceId":"e3d4686d-5d2a-42c7-a471-1efb761646d4","timestamp":"2022-04-17T04:53:27.797Z"}

• GET

curl -H "Content-Type: application\json" -X GET 'http://localhost:8090/api/devices/e3d4686d-5d2a-42c7-a471-1efb761646d4?fromDate=2022-04-16T04:49:08.102Z&toDate=2023-04-17T04:49:08.102Z'
{
  "deviceId": "e3d4686d-5d2a-42c7-a471-1efb761646d4",
  "longitude": -120.9762,
  "latitude": 41.25,
  "data": [
    {
      "humidity": 123,
      "temperature": {
        "unit": "C",
        "value": "23.3"
      },
      "timestamp": "2022-04-17T04:53:01.410Z"
    },
    {
      "humidity": 123,
      "temperature": {
        "unit": "F",
        "value": "223.3"
      },
      "timestamp": "2022-04-17T04:53:27.797Z"
    }
  ]
}

System

Design

• The project applies CQRS patterns (Single Responsibility principle of SOLID) to separate write behavior from read behavior to provide stability and scalability of these services.

Tech Stack

• Springboot: a fast development tool for Spring based application. Spring framework provides IoC container that is an implementation of DI principle, it helps to make the code cleaner.
• Kafka: provide high-throughput, low-latency system platform for real-time data processing.
• Mongodb: it allows storing documents with a flexible schema. It is also easy to access documents using indexing.
• Kafka and MongoDB are both distributed system, they are easy to scale.

Summary

• Preparation: 2 hours (including setup development environment)
• Coding: 7 hours (including tests, fixing bugs, refactoring code)
• Documentation: 30 minutes
• Building and testing: 30 minutes
• Grand total: 10 hours