About this library

A multi-user library system showing the same Java OOP design from the Computer Programming 2 syllabus — ported to ES2022 so it runs as a static GitHub Pages site.

How it works

• Members sign in to borrow books, see their active loans and any outstanding fines.
• Librarians issue and return loans, register new books and members.
• Admins do everything: manage staff, run reports, export the catalogue as CSV.

Loan rules

• Standard loan period: 14 days.
• Overdue fine: $0.25 per day, computed automatically on return.
• A book cannot be loaned if no copies are available.

Demo accounts

Java OOP concepts implemented

• Encapsulation — private # fields with validated setters.
• Inheritance — abstract User extended by Admin / Librarian / Member.
• Polymorphism — describePermissions() overridden in every subclass.
• Abstraction / interfaces — generic Persistable<T> DAO contract.
• Exception hierarchy — LibraryException → Authentication, BookNotAvailable, Validation, NotFound.
• File I/O — RFC-4180-aware CSV import / export.
• Multi-user with auth + authorisation — role-based dashboards, requireAction() guards.