Library Management System

[NandiniGanvir]

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

class Book {
private String title;
private String author;
private String genre;
private boolean available;

public Book(String title, String author, String genre) {
    this.title = title;
    this.author = author;
    this.genre = genre;
    this.available = true;
}

public String getTitle() {
    return title;
}

public String getAuthor() {
    return author;
}

public String getGenre() {
    return genre;
}

public boolean isAvailable() {
    return available;
}

public void setAvailable(boolean available) {
    this.available = available;
}

}

class Patron {
private String name;
private String contactInfo;
private ArrayList borrowedBooks;

public Patron(String name, String contactInfo) {
    this.name = name;
    this.contactInfo = contactInfo;
    this.borrowedBooks = new ArrayList<>();
}

public String getName() {
    return name;
}

public String getContactInfo() {
    return contactInfo;
}

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

public void borrowBook(Book book) {
    borrowedBooks.add(book);
    book.setAvailable(false);
}

public void returnBook(Book book) {
    borrowedBooks.remove(book);
    book.setAvailable(true);
}

}

public class LibraryManagementSystem {
private HashMap<String, Book> books;
private HashMap<String, Patron> patrons;
private HashMap<Book, Patron> borrowedBooks;

public LibraryManagementSystem() {
    this.books = new HashMap<>();
    this.patrons = new HashMap<>();
    this.borrowedBooks = new HashMap<>();
}

public void addBook(String title, String author, String genre) {
    Book book = new Book(title, author, genre);
    books.put(title, book);
}

public void addPatron(String name, String contactInfo) {
    Patron patron = new Patron(name, contactInfo);
    patrons.put(name, patron);
}

public void borrowBook(String patronName, String bookTitle) {
    Patron patron = patrons.get(patronName);
    Book book = books.get(bookTitle);
    if (patron != null && book != null && book.isAvailable()) {
        patron.borrowBook(book);
        borrowedBooks.put(book, patron);
        System.out.println("Book \"" + bookTitle + "\" borrowed by " + patronName);
    } else {
        System.out.println("Book \"" + bookTitle + "\" is not available for borrowing or patron \"" + patronName + "\" does not exist.");
    }
}

public void returnBook(String patronName, String bookTitle) {
    Patron patron = patrons.get(patronName);
    Book book = books.get(bookTitle);
    if (patron != null && book != null && !book.isAvailable() && patron.getBorrowedBooks().contains(book)) {
        patron.returnBook(book);
        borrowedBooks.remove(book);
        System.out.println("Book \"" + bookTitle + "\" returned by " + patronName);
    } else {
        System.out.println("Book \"" + bookTitle + "\" was not borrowed by patron \"" + patronName + "\".");
    }
}

public static void main(String[] args) {
    LibraryManagementSystem library = new LibraryManagementSystem();

    // Add books
    library.addBook("Book1", "Author1", "Genre1");
    library.addBook("Book2", "Author2", "Genre2");

    // Add patrons
    library.addPatron("Patron1", "ContactInfo1");
    library.addPatron("Patron2", "ContactInfo2");

    // Patron1 borrows Book1
    library.borrowBook("Patron1", "Book1");

    // Patron2 tries to borrow Book1 (should fail)
    library.borrowBook("Patron2", "Book1");

    // Patron1 returns Book1
    library.returnBook("Patron1", "Book1");

    // Patron2 borrows Book1
    library.borrowBook("Patron2", "Book1");
}

}