Java Spring Factory Pattern Example

This is a Java Spring project that demonstrates the implementation of the Factory pattern. The Factory pattern is a creational design pattern that provides an interface for creating objects but allows subclasses to decide which class to instantiate.

Prerequisites

To run this project, you need to have the following installed:

• Java 17
• Apache Maven

Getting Started

Follow the steps below to get a local copy of the project and run it on your machine.

1. Clone the repository:

   git clone https://github.com/DenilssonMontoya/java-spring-factory-pattern.git

2. Navigate to the project directory:

   cd java-spring-factory-pattern

3. Build the project using Maven:

   ./mvnw clean install

4. Run the application:

   ./mvnw spring-boot:run

5. The application should now be running on http://localhost:8080.

Implementation Details

This project demonstrates the Factory pattern by providing an example of a FeeCalculatorIF interface and its concrete implementations: CorporateAccountFeeCalculator and PersonalAccountFeeCalculator. The FeeCalculatorFactory class acts as the factory, responsible for creating instances of different types of fee calculator based on a provided account type.

The key components of this implementation are as follows:

• FeeCalculatorIf interface: Defines the contract for all fee-calculators in the system. It includes the method calculateFee().

• CorporateAccountFeeCalculator and PersonalAccountFeeCalculator classes: Concrete implementations of the FeeCalculatorIf interface. They provide specific behavior for fee calculation.

• AccountType annotation type: Single value annotation that allows us to assign a value related to the account types.

• FeeCalculatorFactory class: The factory class that encapsulates the logic for creating instances of different fee calculator types based on the provided account type.

• AccountController class: A Spring MVC controller that demonstrates the usage of the factory pattern. It exposes two REST endpoints /account/v1/create and /account/v1/calculate-fee/{accountId}, the first one allows to create an account and the second one accepts an account id then returns the result of invoking the calculateFee() method on the corresponding fee-calculator instance created by the factory.