Stock APIs

Motivation

This project is an assignment. Implemented code would be a nice example of Stock data APIs.

Features

Stock APIs provides

• Create, update and fetch stock data using HTTP endpoints.

• Used AKKA to achieve fine grained control of the consistency level for reads and writes.

• Scalable and highly available NoSQL data store.

• Made a sample UI, go to the frontend-angular-app directory and follow the readme.

How to run

Prerequisite

• JDK 1.8 (Tested with Oracle JDK)

• Maven 3.6.x+

• Docker (18.09.2), Docker Compose (1.23.2)

Run Cassandra in Docker

$ docker-compose up

Build

$ mvn clean compile install

Run

$ java -jar target/stock-api-1.0.0.jar

or

$ mvn spring-boot:run

Quick test

Create Stock

curl -X POST localhost:8080/api/stocks \
-H 'Content-Type: application/json' \
-d '{ "name": "Apple", "currentPrice": 10.0 }'

example response

{"id":"b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1"}

Get first page of Stocks

curl -X GET localhost:8080/api/stocks \
-H 'Content-Type: application/json'

example response

{
   "data":[
      {
         "id":"b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1",
         "name":"Apple",
         "currentPrice":10.0,
         "lastUpdate":1563738072242
      }
   ],
   "pageNo":0,
   "pageSize":10
}

Get second page of Stocks

curl -X GET 'http://localhost:8080/api/stocks?pageNo=1&pageSize=10' \
-H 'Content-Type: application/json'

example response

{
   "data":[

   ],
   "pageNo":1,
   "pageSize":10
}

Get stock by id

curl -X GET 'http://localhost:8080/api/stocks/b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1' \
-H 'Content-Type: application/json'

example response

{
   "id":"b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1",
   "name":"Apple",
   "currentPrice":10.0,
   "lastUpdate":1563738072242
}

Update Stock by id

curl -X PUT 'http://localhost:8080/api/stocks/b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1' \
-H 'Content-Type: application/json' \
-d '{ "name": "Apple Inc", "currentPrice": 20.0 }'

example response

{
   "id":"b9ee0544-1a4d-4ae5-b22e-3a05e4c4c6f1",
   "name":"Apple Inc",
   "currentPrice":20.0,
   "lastUpdate":1563741056100
}

Design Decisions

• According to assignment, Stock Id should be number.

  • Choose String instead of long / int. Type 4 UUID create hard to predict id, better than predictable number id.

  • Usually better that number but has it’s own flaw. Just a choice.

• According to assignment, the list of stocks should be created in memory on application startup.

  • Did not do it because in-memory cache could cause cache consistency problem during scaling.

  • Added dummy data on dev profile to demo purpose.

• Authentication and authorization is not taking into consideration.

• AKKA creates mailbox (queue) that perform action on data. Provides fine grained control over reads and writes of current price of stocks.

• NoSQL data store is an obvious choice. Cassandra provides high scalability and availability.

• Choose Reactive REST endpoint with Spring WebFlux because AKKA is already reactive and it consumes less resource.

Development

How to run tests

How to run unit tests

To run the unit tests, execute the following commands

mvn clean test-compile test

How to run integration tests

To run the integration tests, execute the following commands

mvn clean test-compile verify -DskipTests=true

How to run both unit tests and integration tests

To run the integration tests, execute the following commands

mvn clean test-compile verify

How to run pitest

To run the mutation tests, execute the following commands

mvn clean test-compile test
mvn org.pitest:pitest-maven:mutationCoverage

Improvements to make

• Improve architectural design, completed the project in 12 hours.

• Code improvements

  • Type casting in REST controller and in StockActor is not nice, need to fix it. First time working with AKKA and WebFlux.

  • Use Cassandra with reactive spring repository.

• Build docker image (plugin already added in the pom).

• Generate and check OWASP report.

• Improve code coverage, e.g. adding end-to-end tests.

Copyright & License

Licensed under the MIT License, see the LICENSE file for details.