Interactive Library System

A console & GUI-based Library Management System built in Java as part of the CMP5332 Object-Oriented Programming module at BCU (Birmingham City University) — Group D7.

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Features

• Book Management — Add, list, view details, and soft-delete books
• Patron Management — Add, list, view details, and soft-delete patrons
• Borrowing System — Issue, renew, and return books with due-date tracking
• Loan Tracking — Tracks who borrowed which book and when it is due
• Data Persistence — Books, patrons, and loans are saved to/loaded from text files
• Dual Interface — Interactive command-line (CLI) and a full Swing-based GUI
• Unit Tests — JUnit 5 + Mockito test suite for Book and Patron models

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Project Structure

src/bcu/D7/librarysystem/
├── main/
│   ├── Main.java              # Entry point (CLI REPL)
│   ├── CommandParser.java     # Parses user input into Command objects
│   └── LibraryException.java  # Custom exception class
├── model/
│   ├── Book.java              # Book entity with soft-delete & loan status
│   ├── Patron.java            # Patron entity (max 2 books per patron)
│   ├── Loan.java              # Loan entity (patron + book + dates)
│   └── Library.java           # Central library: holds books & patrons
├── commands/
│   ├── Command.java           # Command interface + help message
│   ├── AddBook.java           # Add a new book
│   ├── AddPatron.java         # Add a new patron
│   ├── BorrowBook.java        # Borrow a book
│   ├── RenewBook.java         # Renew a borrowed book
│   ├── ReturnBook.java        # Return a borrowed book
│   ├── DeleteBook.java        # Soft-delete a book
│   ├── DeletePatron.java      # Soft-delete a patron
│   ├── ShowBook.java          # Show detailed book info
│   ├── ShowPatron.java        # Show detailed patron info
│   ├── ListBooks.java         # List all books
│   ├── ListPatrons.java       # List all patrons
│   ├── LoadGUI.java           # Launch the Swing GUI
│   └── Help.java              # Display available commands
├── data/
│   ├── DataManager.java       # Interface for data load/store
│   ├── LibraryData.java       # Orchestrates all data managers
│   ├── BookDataManager.java   # Reads/writes books.txt
│   ├── PatronDataManager.java # Reads/writes patrons.txt
│   └── LoanDataManager.java   # Reads/writes loans.txt
├── gui/
│   ├── MainWindow.java        # Main Swing window with menus
│   ├── AddBookWindow.java     # Dialog to add a book
│   ├── AddPatronWindow.java   # Dialog to add a patron
│   ├── IssueBookWindow.java   # Dialog to issue a book
│   └── ReturnBookWindow.java  # Dialog to return a book
└── test/
    ├── BookTest.java          # Unit tests for Book (JUnit 5 + Mockito)
    └── PatronTest.java        # Unit tests for Patron (JUnit 5 + Mockito)

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How to Run

CLI Mode

# Compile (from the project root)
javac -d out src/bcu/D7/librarysystem/**/*.java

# Run
java -cp out bcu.D7.librarysystem.main.Main

GUI Mode

From the CLI, type loadgui after launching, or run the MainWindow directly.

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Available Commands

Command	Description
addbook	Add a new book
addpatron	Add a new patron
listbooks	List all books
listpatrons	List all patrons
showbook <id>	Show detailed book info
showpatron <id>	Show detailed patron info
borrow <pid> <bid>	Borrow a book
renew <pid> <bid>	Renew a borrowed book
return <pid> <bid>	Return a borrowed book
loadgui	Launch the Swing GUI
help	Show this help message
exit	Exit the program

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Data Storage

Data is persisted in resources/data/ as plain text files:

• books.txt — Book records
• patrons.txt — Patron records
• loans.txt — Loan records

All data is loaded on startup and saved on exit.

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Built With

• Java (standard edition, no frameworks)
• Swing — GUI toolkit
• JUnit 5 + Mockito — Unit testing
• Plain text files — Data persistence