The main use case for this API is to calculate realtime statistic from the last 60 seconds. There are two APIs, one of them is called every time a transaction is made. It is also the sole input of this rest API. The other one returns the statistic based of the transactions of the last 60 seconds.

Every time a new transaction happened, this endpoint is called.

Request

POST /transactions HTTP/1.1
Host: localhost:8080
Content-Type: application/json
{
  "amount": 9.99, 
  "timestamp": 1529750938000
}

Response

Returns empty body with either 201 or 204.

• 201 - in case of success
• 204 - if transaction is older than 60 seconds

HTTP/1.1 201 Created
Content-Type: application/json

It returns the statistic of transactions happened in the last 60 seconds.

Request

GET /statistics HTTP/1.1
Host: localhost:8080

Response

HTTP/1.1 200
Content-Type: application/json;charset=UTF-8
{
    "sum": 1179.89,
    "avg": 168.5557142857143,
    "max": 999.5,
    "min": 0.99,
    "count": 7
}

In order to build this application, run the following gradle command:

gradlew build

To run this applicatin, use the following gradle command:

gradlew bootRun

MIT