Transaction Manager

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Project Description

The project is crafted in Java 17, leveraging the Spring Boot Framework, and using PostgreSQL as the database. Also uses Docker to deploy both the application and the database within a cloud environment.

To access real-time exchange rates, I chose the ExchangeRate-API because it offered extensive usage for free and allowed me to specify the base currency without any charges. To make it simpler, only the following currencies were used:

USD: United States Dollar
EUR: Euro
GBP: British Pound Sterling
JPY: Japanese Yen
AUD: Australian Dollar
CAD: Canadian Dollar
CNY: Chinese Yuan
INR: Indian Rupee
CHF: Swiss Franc
SEK: Swedish Krona
NZD: New Zealand Dollar
KRW: South Korean Won
SGD: Singapore Dollar
TRY: Turkish Lira
RUB: Russian Ruble
ZAR: South African Rand
BRL: Brazilian Real
KPW: North Korean Won

Note: The ExchangeRate-API does not support the North Korean Won (KPW). However, for testing purposes and to ensure that a fund transfer fails when the exchange rate cannot be retrieved, this currency is supported within the application. You can view the list of supported and unsupported currencies here.

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Running the Application:

Setup Instructions

Clone the project to your local machine:

git clone https://github.com/renatompf/transaction_manager.git

Running the Project

Once the project is on your device, execute the following command to run it:

make run

This command initiates the database, imports the necessary data, and starts the program execution. You can access the application at localhost:8080.

Running Tests

At last, to run the tests you can make:

make test

Stopping the Project

In case you want to stop everything, you can do the following:

make stop

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API Endpoints Overview:

Account Endpoints

These endpoints are dedicated to managing User Accounts. Each user account is crucial for identifying the owner of respective bank accounts.

Create Account

• Endpoint: POST /accounts
• Description: Creates a new user account based on the provided request data.
• Request Body: CreateAccountRequest
• Response: AccountDTO
• HTTP Response Code: 201 (Created)

Example:

POST /accounts
Content-Type: application/json

{
  "firstName": "Albert",
  "lastName": "Einstein",
  "email": "albert.einstein@example.com",
  "dateOfBirth": "1879-03-14"
}

Get All Accounts

• Endpoint: GET /accounts
• Description: Retrieves a paginated list of all user accounts.
• Parameters: Pageable (for pagination)
• Response: Paginated list of AccountDTO
• HTTP Response Code: 200 (OK)

Example:

GET /accounts?page=0&size=10

Get Account by ID

• Endpoint: GET /accounts/{id}
• Description: Retrieves an user account by its ID.
• Path Variable: id (Account ID)
• Response: AccountDTO
• HTTP Response Code: 200 (OK)

Example:

GET /accounts/1

Delete Account by ID

• Endpoint: DELETE /accounts/{id}
• Description: Deletes an user account by its ID.
• Path Variable: id (Account ID)
• Response: Boolean indicating successful deletion
• HTTP Response Code: 200 (OK)

Example:

DELETE /accounts/1

Bank Accounts Endpoints

These endpoints are dedicated to managing Bank Accounts.

Create Bank Account

• Endpoint: POST /bank-accounts
• Description: Creates a new bank account based on the provided request data.
• Request Body: CreateBankAccountRequest
• Response: BankAccountDTO
• HTTP Response Code: 201 (Created)

Example:

POST /bank-accounts
Content-Type: application/json

{
  "ownerId": 1, // User Account ID
  "currency": "USD",
  "balance": 300000
}

Get All Bank Accounts

• Endpoint: GET /bank-accounts
• Description: Retrieves a paginated list of all bank accounts.
• Parameters: Pageable (for pagination)
• Response: Paginated list of BankAccountDTO
• HTTP Response Code: 200 (OK)

Example:

GET /bank-accounts?page=0&size=10

Get Bank Account by ID

• Endpoint: GET /bank-accounts/{id}
• Description: Retrieves a bank account by its ID.
• Path Variable: id (Bank Account ID)
• Response: BankAccountDTO
• HTTP Response Code: 200 (OK)

Example:

GET /bank-accounts/1

Delete Bank Account by ID

• Endpoint: DELETE /bank-accounts/{id}
• Description: Deletes a bank account by its ID.
• Path Variable: id (Bank Account ID)
• Response: Boolean indicating successful deletion
• HTTP Response Code: 200 (OK)

Example:

DELETE /bank-accounts/1

Transaction Endpoints

These endpoints are dedicated to managing Transactions.

Create New Transaction

• Endpoint: POST /transactions
• Description: Creates a new transaction based on the provided request data.
• Request Body: CreateNewTransactionRequest
• Response: TransactionDTO
• HTTP Response Code: 201 (Created)

Example:

POST /transactions
Content-Type: application/json

{
  "from": 2, // Source Bank Account ID
  "to": 1,  // Destination Bank Account ID
  "amount": 1000 // The amount will be considered to be in the same currency as the Souce Bank Account and will be converted if needed.
}

(Please check Notes, point 1)

Get All Transactions

• Endpoint: GET /transactions
• Description: Retrieves a paginated list of all transactions.
• Parameters: Pageable (for pagination)
• Response: Paginated list of TransactionDTO
• HTTP Response Code: 200 (OK)

Example:

GET /transactions?page=0&size=10

Get Transaction by ID

• Endpoint: GET /transactions/{id}
• Description: Retrieves a transaction by its ID.
• Path Variable: id (Transaction ID)
• Response: TransactionDTO
• HTTP Response Code: 200 (OK)

Example:

GET /transactions/1

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Notes:

1. When creating a new transaction, the ExchangeRate-API is called to check real-time data. That can only happen by using an API KEY. This API KEY is exposed in the application.properties file. If for some reason, the calls made to the ExchangeRate-API starting failing, even for the most common currencies. Try to generate one here and replace it in the application.properties file.