LibraryManagement.java

import java.util.ArrayList;
import java.util.Scanner;

class Book {
    private String title;
    private String author;
    private String isbn;
    private boolean isAvailable;

    public Book(String title, String author, String isbn) {
        this.title = title;
        this.author = author;
        this.isbn = isbn;
        this.isAvailable = true;
    }

    public String getIsbn() {
        return isbn;
    }

    public boolean isAvailable() {
        return isAvailable;
    }

    public void setAvailable(boolean available) {
        isAvailable = available;
    }

    public void displayBookDetails() {
        System.out.println("Title: " + title);
        System.out.println("Author: " + author);
        System.out.println("ISBN: " + isbn);
        System.out.println("Status: " + (isAvailable ? "Available" : "Borrowed"));
    }
    
    public String getTitle() {
        return title;
    }
}

class Member {
    private int memberId;
    private String name;
    private ArrayList<Book> borrowedBooks;
    private static int nextMemberId = 101;

    public Member(String name) {
        this.memberId = nextMemberId++;
        this.name = name;
        this.borrowedBooks = new ArrayList<>();
    }

    public int getMemberId() {
        return memberId;
    }

    public String getName() {
        return name;
    }

    public ArrayList<Book> getBorrowedBooks() {
        return borrowedBooks;
    }

    public void displayMemberDetails() {
        System.out.println("Member ID: " + memberId);
        System.out.println("Name: " + name);
        System.out.println("Borrowed Books: " + borrowedBooks.size());
        if (!borrowedBooks.isEmpty()) {
            System.out.println(" Currently Borrowed Books ");
            for (Book book : borrowedBooks) {
                System.out.println("  - " + book.getIsbn() + " (" + book.getTitle() + ")");
            }
        }
    }
}

class Library {
    private ArrayList<Book> books;
    private ArrayList<Member> members;

    public Library() {
        this.books = new ArrayList<>();
        this.members = new ArrayList<>();
    }

    public void addBook(Book book) {
        books.add(book);
        System.out.println("Book '" + book.getTitle() + "' added to the library.");
    }

    public void registerMember(Member member) {
        members.add(member);
        System.out.println("Member '" + member.getName() + "' registered with ID: " + member.getMemberId());
    }

    public void lendBook(String isbn, int memberId) {
        Book bookToLend = findBook(isbn);
        Member member = findMember(memberId);

        if (bookToLend == null) {
            System.out.println("Error: Book with ISBN " + isbn + " not found.");
            return;
        }

        if (member == null) {
            System.out.println("Error: Member with ID " + memberId + " not found.");
            return;
        }

        if (!bookToLend.isAvailable()) {
            System.out.println("Error: Book '" + bookToLend.getTitle() + "' is currently borrowed.");
            return;
        }

        bookToLend.setAvailable(false);
        member.getBorrowedBooks().add(bookToLend);
        System.out.println("Book '" + bookToLend.getTitle() + "' successfully lent to " + member.getName());
    }

    public void returnBook(String isbn, int memberId) {
        Book bookToReturn = findBook(isbn);
        Member member = findMember(memberId);

        if (bookToReturn == null) {
            System.out.println("Error: Book with ISBN " + isbn + " not found.");
            return;
        }

        if (member == null) {
            System.out.println("Error: Member with ID " + memberId + " not found.");
            return;
        }

        if (!member.getBorrowedBooks().remove(bookToReturn)) {
            System.out.println("Error: The book '" + bookToReturn.getTitle() + "' was not borrowed by this member.");
            return;
        }

        bookToReturn.setAvailable(true);
        System.out.println("Book '" + bookToReturn.getTitle() + "' successfully returned by " + member.getName());
    }

    public void displayAllBooks() {
        System.out.println(" Library Book Catalog ");
        for (Book book : books) {
            book.displayBookDetails();
          
        }
    }

    public void displayAllMembers() {
        System.out.println("Registered Members ");
        for (Member member : members) {
            member.displayMemberDetails();
       
        }
    }

    private Book findBook(String isbn) {
        for (Book book : books) {
            if (book.getIsbn().equals(isbn)) {
                return book;
            }
        }
        return null;
    }

    private Member findMember(int memberId) {
        for (Member member : members) {
            if (member.getMemberId() == memberId) {
                return member;
            }
        }
        return null;
    }
}

public class LibraryManagement {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        Library library = new Library();

        // Adding some initial books and members for demonstration
        library.addBook(new Book("The Lord of the Rings", "J.R.R. Tolkien", "9780618640685"));
        library.addBook(new Book("Pride and Prejudice", "Jane Austen", "9780141439518"));
        library.addBook(new Book("To Kill a Mockingbird", "Harper Lee", "9780061120084"));

        library.registerMember(new Member("Alice"));
        library.registerMember(new Member("Bob"));

        while (true) {
            System.out.print("\033[H\033[2J");
            System.out.flush();
            
            System.out.println("      Library Management System       ");
            
            System.out.println("1. Lend a Book");
            System.out.println("2. Return a Book");
            System.out.println("3. Display All Books");
            System.out.println("4. Display All Members");
            System.out.println("5. Exit");
           
            System.out.print("Enter your choice: ");

            String choice = scanner.nextLine();

            switch (choice) {
                case "1":
                    System.out.print("Enter ISBN of the book to lend: ");
                    String isbnToLend = scanner.nextLine();
                    System.out.print("Enter member ID: ");
                    try {
                        int memberIdToLend = Integer.parseInt(scanner.nextLine());
                        library.lendBook(isbnToLend, memberIdToLend);
                    } catch (NumberFormatException e) {
                        System.out.println("Invalid member ID. Please enter a number.");
                    }
                    break;
                case "2":
                    System.out.print("Enter ISBN of the book to return: ");
                    String isbnToReturn = scanner.nextLine();
                    System.out.print("Enter member ID: ");
                    try {
                        int memberIdToReturn = Integer.parseInt(scanner.nextLine());
                        library.returnBook(isbnToReturn, memberIdToReturn);
                    } catch (NumberFormatException e) {
                        System.out.println("Invalid member ID. Please enter a number.");
                    }
                    break;
                case "3":
                    library.displayAllBooks();
                    break;
                case "4":
                    library.displayAllMembers();
                    break;
                case "5":
                    System.out.println("\nExiting the Library Management System. Goodbye!");
                    return;
                default:
                    System.out.println("\nInvalid choice. Please try again.");
                    break;
            }
            System.out.println("\nPress Enter to continue...");
            scanner.nextLine();
        }
    }
}