🛒 Market Management System – Overview

This project is a simple market management system implemented in Java using a clean and modular architecture. It is divided into five main layers:

• exception
• model
• repository
• service
• ui

The goal is to practice separation of concerns and prepare the codebase for future scalability (e.g., JPA, databases, REST APIs).

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📦 Model Layer

This layer contains the domain entities. All classes are POJOs (Plain Old Java Objects) with fields, constructors, and getters/setters. They will be ready for future JPA/Hibernate annotations.

CarritoItem

Represents an item inside the shopping cart. Attributes:

• cantidad (int)
• producto (Producto)

Producto (abstract)

Base class for products in the system. Attributes:

• id (int)
• nombre (String)
• precioBase (double)
• stock (int)

ProductoAlimenticio

Extends Producto. New attribute:

• fecha_caducidad (Date)

ProductoElectronico

Extends Producto. New attribute:

• garantia (int)

Venta

Represents a completed sale. Attributes:

• id
• fecha
• items (List)
• total (double)

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🗃️ Repository Layer

This layer defines interfaces that describe how data is accessed. Each repository has an in-memory implementation using Map to store data.

CarritoRepository

• insertar(id, item)
• buscarItem(id)
• buscarTodos()
• vaciarCarrito()

ProductoRepository

• insertar()
• actualizar()
• borrar()
• buscarPorId()
• buscarTodos()

VentaRepository

• insertarVenta()
• mostrarHistorial()

Memory implementations:

• CarritoRepositoryMemory
• ProductoRepositoryMemory
• VentaRepositoryMemory

These mimic a database and will be replaceable by JPA in the future.

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⚙️ Service Layer

This layer contains the business logic.

CarritoService

Uses:

• ProductoRepository (product catalog)
• CarritoRepository (current cart)
• VentaRepository (sale history)

Implements:

• getCatalog() → returns all products
• agregarAlCarrito(id, cantidad)
• verCarrito()
• buscarProducto(id)
• calcularSubtotal(item)
• calcularTotal(items)
• pagar() → creates a Venta, adds to history, and empties the cart

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🖥️ UI Layer

This layer handles console input/output.

MenuPrincipal

Contains:

• A Scanner
• Methods to display menus, show catalog, show cart, show product info, show sale info
• Utility methods: pedirID, pedirCantidad, pausar

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▶️ Main

The Main class coordinates the entire flow:

1. Instantiates repositories (catalog, empty cart, sale history)

2. Instantiates the service

3. Instantiates the UI

4. Runs a while loop with a switch menu:

   • 1: Show catalog and add items to cart
   • 2: View current cart
   • 3: Pay → generate a sale and store it
   • 4: Exit

Aquí tienes un recordatorio profesional, corto y claro para poner al final de tu README:

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⚠️ Pending Improvements (To-Do)

This project is functional, but several improvements are planned for the next iteration:

• Add custom exceptions for validation and error handling
• Refactor services into smaller, more cohesive units
• Further separate UI logic from business logic
• Improve domain models (POJOs) to prepare for future scalability (JPA, REST APIs, databases)

These upgrades will make the system more robust, modular, and easier to extend.

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