FitZone - Client Management System

A console-based client management system for fitness zone memberships built with Java and MySQL.

📋 Overview

FitZone enables comprehensive CRUD (Create, Read, Update, Delete) operations on client records, including:

• Listing all clients
• Searching by identifier
• Adding new clients
• Modifying existing client information
• Deleting clients

The system uses a dual-identifier approach where idClient serves as the database primary key with auto-increment functionality, while membershipNumber serves as the business identifier with unique constraint enforcement.

🏗️ System Architecture

FitZone follows a classic three-tier layered architecture with clear separation of concerns:

Layer	Components	Responsibilities
Presentation	ZonaFitApp class	Menu display, user input handling, operation coordination
Domain	Client class	Business entity representation, data encapsulation
Data Access	IClientDAO interface, ClientDAO implementation	Database operations abstraction, SQL execution
Persistence	MySQL fit_zone_db database	Data storage, constraint enforcement

🛠️ Technology Stack

Component	Technology	Version	Purpose
Programming Language	Java	25	Application development
Build Tool	Maven	4.0.0	Dependency management, build automation
Database	MySQL	8.0.44	Data persistence
JDBC Driver	MySQL Connector/J	9.5.0	Database connectivity
Character Encoding	UTF-8	-	Source file and database encoding

Maven Coordinates: fit_zone:FitZone:1.0-SNAPSHOT

🚀 Key Features

CRUD Operations

FitZone provides six main operations through its console menu interface:

Operation	Method	Description
List Clients	showClientsList()	Retrieves and displays all clients ordered by idClient
Search Client	searchClient()	Searches for a client by database ID or membership number
Add Client	addNewClient()	Creates a new client record with duplicate prevention
Modify Client	modifyClient()	Updates client information identified by membership number
Delete Client	removeClient()	Removes a client record by either identifier type
Exit	Return flag	Terminates the application loop

🗄️ Database Schema

The persistence layer consists of a single MySQL database with one primary table:

Database: fit_zone_db
Character Set: utf8mb4 with utf8mb4_0900_ai_ci collation
Engine: InnoDB

Primary Table: clients

Column Name	Data Type	Constraints	Purpose
idClient	INT	PRIMARY KEY, AUTO_INCREMENT	Database primary key
first_name	VARCHAR(50)	NOT NULL	Client's first name
last_name1	VARCHAR(50)	NOT NULL	Client's primary surname
last_name2	VARCHAR(50)	NULL	Client's secondary surname (optional)
membership_number	INT	UNIQUE	Business identifier for the client
registration_date	TIMESTAMP	DEFAULT CURRENT_TIMESTAMP	Automatic creation timestamp
last_updated	TIMESTAMP	ON UPDATE CURRENT_TIMESTAMP	Automatic modification timestamp

🎯 Application Entry Point

The application starts through the ZonaFitApp class with the following initialization sequence:

1. Main Method: Entry point that calls MainApp()
2. MainApp() Method: Initializes the application
   • Creates IClientDAO instance using ClientDAO implementation
   • Initializes Scanner for user input
   • Enters menu loop until exit flag is set
3. Menu Loop: Continuously displays menu and processes user selections
4. Error Handling: Try-catch block wraps menu operations with console error output

📦 Build Configuration

The project uses Maven for build management with the following configuration:

• Project Coordinates:

  • Group ID: fit_zone
  • Artifact ID: FitZone
  • Version: 1.0-SNAPSHOT

• Compiler Settings:

  • Source Compatibility: Java 25
  • Target Compatibility: Java 25
  • Source Encoding: UTF-8

• Dependencies:

  • com.mysql:mysql-connector-j:9.5.0

🎨 Design Patterns

FitZone implements several established software design patterns:

• DAO (Data Access Object) Pattern: Abstracts database operations through IClientDAO interface
• Layered Architecture: Clear separation between presentation, domain, and data access layers
• Factory Pattern (Simplified): SQLConnection.getConnection() centralizes connection creation
• Domain Model Pattern: Client class represents core business concept with data encapsulation

⚠️ Current Limitations

Limitation	Impact
Hardcoded database credentials	Security risk, deployment inflexibility
No connection pooling	Performance degradation under load
Console-only interface	Limited accessibility and usability
No configuration file support	Cannot change settings without recompilation
Limited error handling	Exceptions may not provide actionable information
No audit logging	Cannot track who performed operations or when
Timestamp fields not mapped	registration_date and last_updated unused in Java

📁 Source Files

• pom.xml - Maven configuration and dependencies
• src/main/java/fit_zone/presentation/ZonaFitApp.java - Main application class
• src/main/resources/db/fit_zone_db.sql - Database creation script

🚀 Getting Started

1. Database Setup: Execute the SQL script to create the database and table
2. Build: Use Maven to compile the project: mvn clean compile
3. Run: Execute the ZonaFitApp class to start the application
4. Configure: Update database connection settings in the SQLConnection class

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For detailed architecture patterns, technology specifications, and component interactions, refer to the comprehensive documentation in the source code.