Typical Layers in Layered Architecture

Layered architecture is a common design pattern in Java applications. It organizes code into separate layers, each with a specific responsibility. This separation improves maintainability, testability, and scalability. The most typical layers are presentation, business, and data access.

Presentation Layer

The presentation layer is responsible for interacting with users or external systems. Its main responsibilities include:

• Displaying data to users;
• Receiving user input and forwarding requests to the business layer;
• Handling input validation and user feedback;
• Managing user interface logic.

In Java applications, this layer is often implemented using technologies such as JavaFX, Swing, or web frameworks like Spring MVC.

Business Layer

The business layer (sometimes called the service layer) contains the core logic of the application. Its responsibilities are:

• Processing requests from the presentation layer;
• Enforcing business rules and workflows;
• Coordinating data transfer between layers;
• Managing transactions and application-specific logic.

This layer is typically implemented using plain Java classes or frameworks like Spring. It should not contain code related to user interfaces or direct data storage.

Data Access Layer

The data access layer (also known as the persistence layer) handles communication with databases or other storage systems. Its responsibilities include:

• Retrieving and storing data in persistent storage;
• Mapping database records to Java objects and vice versa;
• Managing database connections and queries;
• Isolating the business layer from storage details.

Common Java technologies for this layer include JDBC, JPA, and frameworks like Hibernate. By isolating data access logic, you make it easier to change storage solutions or optimize performance without affecting business logic.

Each layer communicates only with the layer directly below or above it. This clear separation helps you organize complex applications and makes future changes more manageable.