Clean Architecture: Implementation Using Quarkus + Gradle Multi-Project. Part 3
Welcome back to the third installment of our blog post series on Clean Architecture with Quarkus and Java 17. In this chapter, we're diving deep into the heart of our system by configuring the
business
module group. This pivotal group houses essential interfaces that define the interactions between our application's core logic, external services, and data repositories.
As we venture further into our architectural journey, we recognize the importance of a well-structured and modular
business
layer. Here, we'll define the contracts that encapsulate our business use cases, data management operations, and external service integrations. By enforcing clear boundaries between these responsibilities, we ensure that our system remains adaptable, maintainable, and aligned with the principles of Clean Architecture.
Throughout this chapter, we'll explore the nuances of setting up the
business
module group, and we'll emphasize the significance of interface-driven development. Let's begin our exploration into configuring the interfaces that define the core of our system's functionality.
Configuring Business Repository Module: Defining Data Persistence Contracts
In this chapter, we're focusing on the
business-repository
module, a key component of the
business
layer. This module is dedicated to encapsulating data repository interfaces that define how our application interacts with the database for persistence operations.
The
business-repository
module serves as a bridge between our core business domain models and the underlying data storage mechanisms. By enforcing clear contracts through interfaces, we ensure that our data persistence operations remain decoupled from implementation details. This separation enhances maintainability, facilitates testing, and fosters a clean and modular architecture.
Dependency Setup
By depending on the
domain-model
module, we establish a direct relationship between our data repository contracts and the core domain models they interact with. This ensures that our repository interfaces align seamlessly with the underlying data structure.
Let's take a look at how to configure the
business-repository
module's dependencies:
dependencies {
implementation project(':domain-model')
}
By including the
implementation project(':domain-model')
line, we establish the necessary relationship between the
business-repository
module and the core domain models.
In this segment, we've configured the
business-repository
module's dependencies, specifically establishing a connection with the
domain-model
module. This setup ensures that our data repository interfaces are directly tied to the core domain models, promoting a cohesive and maintainable architecture.
Configuring Business Service Module: Integrating External Libraries and Services
In this section, we're delving into the configuration of the
business-service
module, a vital piece of the
business
layer. This module acts as a bridge between our core domain models and external libraries and services contracts, encapsulating the integration logic that brings these entities together.
The
business-service
module plays a critical role in orchestrating the interaction between our application's core domain models and external services. These services might include APIs, microservices, or third-party systems. By encapsulating the integration logic within this module, we establish a clear boundary between our internal business logic and the external world.
Dependency Setup
Before we proceed, let's grasp the dependencies that the
business-service
module relies on. Just like the
business-repository
module, the
business-service
module also depends on the
domain-model
module. This dependency ensures that the service contracts defined in this module align seamlessly with the core domain models.
Let's take a closer look at how to configure the
business-service
module's dependencies:
dependencies {
implementation project(':domain-model')
}
By including the
implementation project(':domain-model')
line, we establish a direct relationship between the
business-service
module and the core domain models.
Integrating External Services
The primary role of the
business-service
module is to manage the integration between our core domain models and external service contracts. This includes orchestrating data transformation, request-response interactions, error handling, and more.
In this segment, we've explored the configuration of the
business-service
module, focusing on its dependencies and the integration logic it encapsulates. By depending on the
domain-model
module and managing external service interactions, this module ensures that our core business logic remains insulated from the complexities of external services.
Configuring Business Usecase Module: Encapsulating Business Logic
In this chapter, we're diving into the configuration of the
business/usecase
module. As a central component of the
business
layer, this module encapsulates the contracts for business logic use cases. It's the place where the core application's behavior is defined.
Usecases and Their Significance
The
business/usecase
module plays a pivotal role in articulating the business rules and logic that drive our application. By encapsulating these rules in well-defined use case contracts, we achieve several benefits: clear separation of concerns, maintainability, testability, and adherence to Clean Architecture principles.
Dependency Setup
Before we proceed, let's understand the dependencies that the
business/usecase
module relies on. Similar to previous modules, the
business/usecase
module also depends on the
domain-model
module. This dependency establishes a direct connection between the core business logic and the use cases that operate on it.
Here's how you can configure the
business/usecase
module's dependencies:
dependencies {
implementation project(':domain-model')
}
By including the
implementation project(':domain-model')
line, we establish a direct relationship between the
business/usecase
module and the core domain models.
Defining Usecase Contracts
The core responsibility of the
business/usecase
module is to define contracts for the various business logic use cases. These contracts outline the methods and behaviors that the application's behavior adheres to.
In this segment, we've explored the configuration of the
business/usecase
module, focusing on its dependencies setup and the encapsulation of business logic use case contracts. By defining clear contracts for application behavior, we ensure a well-structured, maintainable, and testable codebase.
You can find the code of this section in the branch: steps/4-configuring-business-interfaces
