Money Transfer api

Overview

This is an API for transferring money between accounts using JAX-RS, Jersey, embedded Tomcat and Maven. A number of assumptions are made, as listed under the API design header.

Building and executing

Use the provided executable:

java -jar transfer-money-api-1.0-SNAPSHOT.jar

Or rebuild the project:

mvn clean compile

mvn package

java -jar target/transfer-money-api-1.0-SNAPSHOT.jar

Endpoints

The embedded server will start on http://localhost:8080/

/transfer/from/{accountFrom}/to/{accountTo}/amount/{amount}

Transfer amount from one account to another. Working example: http://localhost:8080/transfer/from/ABC/to/testAccount/amount/5.5

/account/{accountId}/balance

View balance for given account (for example testAccount) http://localhost:8080/account/testAccount/balance

API design / requirements

Based on the explicit requirements:

• Used by multiple systems and services => will need to be scalable and thread-safe
• In-memory datastore => data is not persisted
• Standalone executable => embedded server is required
• Tests for proving API works (including thread-safety)

Some initial assumptions:

• Account management has its own API and accounts will be assumed to have been created.
• As the use of a database is not required for this exercise, some dummy accounts will be initialized in-memory.
• The usual functions of a bank account will be in a different API (for actions such as deposit, withdraw)
• By using Tomcat I get multi-threading out of the box so I will only need to take care of thread-safety

NOT in scope of this API:

• Account management (creation, closure etc.)
• Depositing, withdrawing

NOT in scope due to time limitations:

• Currencies
• Negative balances (overdraft)
• Transfer history
• Recurring transfers
• Scheduled transfers
• Cancelling transfers
• Reversing transfers
• Money requests
• Customisable reference messages (for transfers)
• Metrics, logging, alarms
• Proper error handling (with explicit exception objects)
• Fraud detection