Bankin API

The idea of this project is to show the application of consuming an API. In here we present two REST API, one to compute the arrondis for each transaction for a given user. The second one computes the aggregation of the arrondis for a given list of users.

Internals

In order to connect to the Bankin API, a client_id and client_secret is required, along with the user email and password credentials. The classes BankinAPI and User are meant to hold these credentials respectively.

After the connection is set up, a promise is returned with the access_token. This promise is passed to the method (another promise) in charge to perform the queries.

Once the query is resolved, the data collected is stored in different classes:

Transactions: Represents one page of transactions from the Bankin API.
Transaction: Represents a single transaction for a given user.
BankinResource: Represents a resource object of Bankin API.
Pagination: Represents the pagination information of each page.
User: Represents a user, with its username and password.
BankinAPIDB and UserDB: Represent a storage for the credentials.

Once the information was retrieved and stored in objects, it follows the next_uri to process the next page. This process is done until the last page is rendered.

To output the results, the objects are treated using Java 8 streams: They are filtered, mapped and collected in order to extract the information relative to the query.

API

Reference

This API provides two REST API:

/arrondis/<user>: It returns a list of transactions, with their amount and arrondis calculated.
/aggregateArrondis/since/until: IT returns the aggregation of all arrondis for all users, along with their email

Usage

To run the project, just open the terminal and run:

$ cd demo_bankinapi
$ sbt run

Open a browser, and query the API as the example:

To retrieve the list of arrondis:

http://localhost:9000/arrondis/user1@mail.com
http://localhost:9000/arrondis/user2@mail.com
http://localhost:9000/arrondis/user3@mail.com

An example response would be:

[{
	"arrondis": 1.51,
	"currency_code": "EUR",
	"amount": -138.49,
	"transaction_id": 38000003650888
}, {
	"arrondis": 3.63,
	"currency_code": "EUR",
	"amount": -26.38,
	"transaction_id": 38000003650892
}]

To retrieve the aggregation:

http://localhost:9000/aggregateArrondis/2010-05-01/2017-06-01
http://localhost:9000/aggregateArrondis/2016-05-01/2016-06-01
http://localhost:9000/aggregateArrondis/2010-05-01/2010-06-01

An example response for the aggregated data would be:

[{
		"currency_code": "EUR",
		"accounts": ["user1@mail.com"],
		"totalArrondis": 306.0
	},
	{
		"currency_code": "USD",
		"accounts": ["user1@mail.com"],
		"totalArrondis": 12.0
	}
]

Test

To run the tests, open a terminal and run: To run the project, just open the folder and run:

$ cd demo_bankinapi
$ sbt test

Documentation

Classes and code contains its own comments explaining how they work.

mcornejo / demo_bankinapi