Question

Objective: Build a program to manage a virtual library, handling book check-outs, returns, and inquiries using static methods.
Problem Statement: Simulate a city library's operations, allowing patrons to check out, return, or inquire about books.
Requirements:
Library operations:
- use static methods like checkOutBook(String title), returnBook(String title) for library actions.
- maintain a list of books using static variables without arrays.
Search features:
- Create static methods to search books by title, author, genre, etc., such as searchByAuthor(String authorName).
Check-out and return system:
- implement static methods to handle check-outs, returns, and due date tracking.
- include fines for late returns and availability checks.
Book Tracking:
- utilize static variables to represent book statuses and create static methods to modify and retrieve this data.

Sample output:
Welcome to the Library Management System!
Choose an action:
1. Check Out Book
2. Return Book
3. Exit
1
Available Books: 99
Choose an action:
1. Check Out Book
2. Return Book
3. Exit
1
Available Books: 98
Choose an action:
1. Check Out Book
2. Return Book
3. Exit
2
Available Books: 99
Choose an action:
1. Check Out Book
2. Return Book
3. Exit
3
Exiting Library Management System.

Answer 1

Below is a simple implementation of the virtual library program as per the specifications provided. Please note that for simplicity, the search features are omitted, and the books are represented using simple book titles and statuses rather than creating a more complex structure with separate classes, arrays, or collections.

```java
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;

public class VirtualLibrary {

private static Map<String, BookStatus> bookCollection = new HashMap<>();
private static Map<String, DueDate> bookDueDates = new HashMap<>();

// A simple representation of a book's status
static class BookStatus {
boolean isCheckedOut;
String title;

BookStatus(String title) {
this.title = title;
this.isCheckedOut = false;
}
}

// A simple representation of a book's due date
static class DueDate {
long dueDateTimestamp;
}

public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int choice;

initializeLibrary(); // Initialize the library with some books

while (true) {
System.out.println("Welcome to the Library Management System!");
System.out.println("Choose an action:");
System.out.println("1. Check Out Book");
System.out.println("2. Return Book");
System.out.println("3. Exit");

choice = scanner.nextInt();
scanner.nextLine(); // Consume the leftover newline

switch (choice) {
case 1: // Check out a book
System.out.print("Enter the title of the book to check out: ");
String checkOutTitle = scanner.nextLine();
checkOutBook(checkOutTitle);
break;
case 2: // Return a book
System.out.print("Enter the title of the book to return: ");
String returnTitle = scanner.nextLine();
returnBook(returnTitle);
break;
case 3: // Exit
System.out.println("Exiting Library Management System.");
scanner.close();
System.exit(0);
break;
default:
System.out.println("Invalid option. Please try again.");
break;
}

System.out.println("Available Books: " + availableBooksCount());
}
}

private static void initializeLibrary() {
// Add books to the library
bookCollection.put("The Great Gatsby", new BookStatus("The Great Gatsby"));
bookCollection.put("1984", new BookStatus("1984"));
// ... initialize more books as needed
}

static void checkOutBook(String title) {
if (!bookCollection.containsKey(title)) {
System.out.println("Book not found!");
return;
}

BookStatus bookStatus = bookCollection.get(title);
if (bookStatus.isCheckedOut) {
System.out.println("Book is already checked out!");
return;
}

bookStatus.isCheckedOut = true;
DueDate dueDate = new DueDate();
dueDate.dueDateTimestamp = System.currentTimeMillis() + (7 * 24 * 60 * 60 * 1000); // Set due date to 7 days from now
bookDueDates.put(title, dueDate);

System.out.println("Book checked out successfully!");
}

static void returnBook(String title) {
if (!bookCollection.containsKey(title)) {
System.out.println("Book not found!");
return;
}

BookStatus bookStatus = bookCollection.get(title);
if (!bookStatus.isCheckedOut) {
System.out.println("Book wasn't checked out!");
return;
}

bookStatus.isCheckedOut = false;

DueDate dueDate = bookDueDates.get(title);
if (dueDate.dueDateTimestamp < System.currentTimeMillis()) {
System.out.println("Book is returned late! Please pay the late fee.");
} else {
System.out.println("Book returned on time. Thank you!");
}

bookDueDates.remove(title);
}

private static int availableBooksCount() {
int availableCount = 0;
for (BookStatus bookStatus : bookCollection.values()) {
if (!bookStatus.isCheckedOut) {
availableCount++;
}
}
return availableCount;
}

// Further methods for searching by author, genre, etc. can be implemented similarly

}
```

This is a simple, console-based implementation of your virtual library requirements. If you require a more complex system, such as one with a GUI or one that uses a relational database or an Object-Oriented design with more classes, those will require further development.