Intro

This repository contains implementation of RESTful Bank Service for money transfer between accounts.

Implementation was created with focus on following requirements:

• Focus on small footprint
• Fast startup time
• Avoid usages of heavy framework

Currently service supports following operations:

• Creating Account
• Listing Accounts with their balance
• List Total Deposit
• Transferring Money between Accounts

Tools used

Below is the list of tools used during development:

• Java 21
• Maven
• SparkJava
• Guice
• OpenAPI
• Swagger Codegen
• Lombok
• JSR 303/380 Bean Validation
• Mockito
• ...

Compiling project

To compile project type:

mvn clean install

Running Project

There are two ways to run project:

• Directly from maven
• Using executable JAR

Running Project with Maven

To run project from maven, execute:

mvn exec:java

Running Project with Executable JAR

To run project from Executable JAR, go to target folder and type:

java -jar bank-service-1.0-SNAPSHOT-jar-with-dependencies.jar

Runtime Configuration

Following properties can be configured during startup by properties:

• host - service.host
• port - service.port
• max threads in pool - service.max.threads

For example, if you want to change port execute:

mvn exec:java -Dservice.port=8081

or from, when using jar:

java -Dservice.port=8081 -jar bank-service-1.0-SNAPSHOT-jar-with-dependencies.jar

API Specification

API is described with OpenAPI, specification is available inside api.yaml. Based on this file DTOs were generated with usage of Swagger Codegen.

Making Request

Checking if service is up

Request:

$ curl http://localhost:8080/ -X GET

Response:

{
  "status": "up"
}

Creating Account

Request:

$ curl http://localhost:8080/accounts -X POST -d '{
  "initialDeposit": "100.00"
}'

Response:

{
  "status": {
    "code": "ACCOUNT_CREATED"
  },
  "account": {
    "accountId": "0481998112065640",
    "balance": 100
  }
}

Listing Accounts and Total Deposit

Request:

$ curl http://localhost:8080/accounts -X GET

Response:

{
  "status": {
    "code": "ACCOUNTS_LISTED"
  },
  "accounts": {
    "accounts": [
      {
        "accountId": "8955895919049153",
        "balance": 100
      },
      {
        "accountId": "0481998112065640",
        "balance": 200
      }
    ],
    "totalDeposit": 300
  }
}

Transferring Money

Request:

$ curl http://localhost:8080/transfer -X POST -d '{
  "from": "8955895919049153",
  "to": "0481998112065640",
  "amount": "50.0"
}'

Response:

{
  "status": {
    "code": "MONEY_TRANSFERRED"
  },
  "moneyTransfer": {
    "from": "1922183208146240",
    "to": "2311254104558146",
    "amount": 50
  }
}

Author

Dominik Cebula

• https://dominikcebula.com/
• https://blog.dominikcebula.com/
• https://www.udemy.com/user/dominik-cebula/