🏋️ Advanced Gym Membership System

A console-based Gym Management System built using Java that helps manage members, trainers, membership plans, attendance, and fee payments with multithreading and file handling support.

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🚀 Features

• 🆔 Auto ID generation for members
• 👤 Add / Remove gym members
• 🔄 Update membership plan
• 📅 Attendance tracking with date
• 💰 Fee payment & payment history
• 🧵 Multithreaded attendance marking
• 💾 Save & Load data using file handling
• 🔍 Search member by ID
• 📋 View all members

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🛠️ Technologies Used

• Java
• OOP (Object-Oriented Programming)
• Collections (ArrayList)
• Multithreading
• File Handling (Serialization)
• Java Time API (LocalDate)
• Exception Handling

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📁 Project Structure

GymManagementSystem
 ├── Main.java
 ├── GymManager.java
 ├── Member.java
 ├── Trainer.java
 ├── Plan.java
 ├── Payment.java
 ├── Attendance.java
 ├── AttendanceThread.java
 └── FileHandler.java

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▶️ How to Run

1. Clone the repository

git clone https://github.com/yogeshkumarsaini/gym-management-system.git

2. Open in any Java IDE (IntelliJ / Eclipse / VS Code)

3. Compile and run:

javac Main.java
java Main

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📌 Sample Menu

🏋️ GYM MENU
1 Add Member
2 Remove Member
3 Update Plan
4 Mark Attendance
5 Pay Fees
6 View Members
7 Save
8 Load
0 Exit

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🧠 OOP Concepts Used

• Encapsulation
• Association
• Abstraction
• Class & Objects

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🔐 Data Storage

All member data is stored in:

gym.dat

using Java Serialization.