Arquitetura em Camadas: Estruturas Eficazes para Desenvolvimento de Software

Introduction to Layered Architecture

Layered architecture is a key approach in software system design. This method organizes a system into different levels of abstraction, assigning specific responsibilities to each layer. This division not only simplifies maintenance and scalability but also isolates responsibilities, creating a more efficient development environment.

What Is Layered Architecture?

In layered architecture, the system is divided into several layers, each focusing on a specific aspect. Layers provide services to the layer above and consume services from the layer below. This structure ensures that changes in one layer minimally impact others, promoting clearer internal organization.

Common Layers in Layered Architecture

The number of layers can vary, depending on the system's complexity and goals. Common layers include:

• Presentation: Manages the user interface and communication with browsers.
• Business: Executes specific operations and business flows.
• Persistence: Responsible for saving and retrieving information.
• Database: Stores data physically.

How Do Layers Interact?

Layers form a strict hierarchy. Each layer accesses only the layer directly below it. For example:

• The presentation layer communicates with the business layer.
• The business layer connects to the persistence layer.
• The persistence layer interacts with the database.

This well-defined flow is crucial to ensure each layer's responsibilities are respected. Thus, changes in one layer do not directly affect others, easing maintenance and system evolution.

Layered Architecture vs. Other Models

It's common to confuse layered architecture with other approaches, such as monoliths or microservices. However, layered architecture is an internal organization model, while deployment models refer to how the system is structured.

You can have:

• A layered monolith
• A layered microservice
• Clean architecture in layers

Variations of Layered Architecture

There are various variations in layered architecture that can include a service layer or group layers into modules. This allows for greater flexibility and customization, depending on project needs. For example, including a service layer can facilitate communication between business and persistence layers, offering a cleaner and more organized interface.

Practical Implementation Examples

Simple Layered Structure Example

// Presentation Layer
function renderUser(user) {
  console.log(`Name: ${user.name}`);
}

// Business Layer
function getUser(userId) {
  return userService.getUserById(userId);
}

// Service Layer
const userService = {
  getUserById(id) {
    return persistenceLayer.getUser(id);
  }
};

// Persistence Layer
const persistenceLayer = {
  getUser(id) {
    // Data retrieval simulation
    return { id, name: 'John' };
  }
};

In this example, each function represents a different layer, showing how communication and responsibility are divided in a layered architecture.

Benefits of Layered Architecture

1. Easier Maintenance: Changes in one layer do not affect others.
2. Scalability: New functionalities can be added without restructuring the entire system.
3. Isolation of Responsibilities: Each layer has a specific function, reducing complexity.
4. Flexibility: Allows for the introduction of new layers or services as needed.

Conclusion

Layered architecture is a powerful approach for structuring software systems. By dividing the system into distinct layers, you can isolate responsibilities, ease maintenance, and promote scalability. This technique not only improves code organization but also ensures your system can adapt to changes over time. Considering layered architecture means investing in a design that can evolve and expand as needed, ensuring the longevity and efficiency of your software.