DSA Java Project – Library Book Management System

Program 1

// Library Book Management System
import java.util.Scanner;

class Book {
    int id;
    String title;
    String author;
    Book prev;
    Book next;

    Book(int id, String title, String author) {
        this.id = id;
        this.title = title;
        this.author = author;
        this.prev = null;
        this.next = null;
    }
}

class Library {
    private Book head;

    public void addBook(int id, String title, String author) {
        Book newBook = new Book(id, title, author);
        if (head == null) {
            head = newBook;
        } else {
            Book temp = head;
            while (temp.next != null) {
                temp = temp.next;
            }
            temp.next = newBook;
            newBook.prev = temp;
        }
        System.out.println("Book added successfully.");
    }

    public void displayBooks() {
        if (head == null) {
            System.out.println("Library is empty.");
            return;
        }
        Book temp = head;
        System.out.println("\nBooks in Library:");
        while (temp != null) {
            System.out.println("ID: " + temp.id + ", Title: " + temp.title + ", Author: " + temp.author);
            temp = temp.next;
        }
    }
public void searchBookById(int id)
{
       Book temp=head;
       while(temp!=null)
       {
          if(temp.id==id)
          {
            System.out.println("Book found: ID = " + temp.id + ", Author = " + temp.author +",Title = " + temp.title);
                return;
          }
          temp=temp.next;
       }
       System.out.println("Book not found with "+id +" id");
}

    public void searchBook(String title) {
        Book temp = head;
        while (temp != null) 
        {
            if (temp.title.equalsIgnoreCase(title)) {
                System.out.println("Book found: ID = " + temp.id + ", Author = " + temp.author);
                return;
            }
            temp = temp.next;
        }
        System.out.println("Book not found with "+title +" title");
    }


    public void searchBookByAuthor(String author) {
        Book temp = head;
        boolean flag=true;
        while (temp != null) 
        {
            if (temp.author.equalsIgnoreCase(author)) {
                System.out.println("Book found: ID = " + temp.id + ", Title = " + temp.title +", Author = " + temp.author);
                flag=false;
            }
            temp = temp.next;
        }
        if(flag==true)
        System.out.println("Book not found with "+author +" Author");
    }



    public void deleteBook(int id) {
        Book temp = head;
        while (temp != null && temp.id != id) {
            temp = temp.next;
        }
        if (temp == null) {
            System.out.println("Book not found.");
            return;
        }
        System.out.println("Book found: ID = " + temp.id + ", Title = " + temp.title +", Author = " + temp.author);
        String choice;
        Scanner scan = new Scanner(System.in);
        System.out.println("Are you sure want to delete(yes/no)");
        choice=scan.next();
      if(choice.toUpperCase().equalsIgnoreCase("YES"))  
      {
        if (temp.prev != null)
            temp.prev.next = temp.next;
        else
            head = temp.next;

        if (temp.next != null)
            temp.next.prev = temp.prev;

        System.out.println("Book deleted successfully.");
      }   
    }

    public void updateBook(int id, Scanner sc) {
        Book temp = head;
        while (temp != null) {
            if (temp.id == id) {
                System.out.print("Enter new title: ");
                sc.nextLine(); // clear buffer
                temp.title = sc.nextLine();
                System.out.print("Enter new author: ");
                temp.author = sc.nextLine();
                System.out.println("Book updated successfully.");
                return;
            }
            temp = temp.next;
        }
        System.out.println("Book not found.");
    }
}

public class LibraryManagementSystem {
    public static void main(String[] args) {
        Library lib = new Library();
        Scanner sc = new Scanner(System.in);
        int choice, id;
        String title, author;

        do {
            System.out.println("\n------------- Library Menu-----------");
            System.out.println("1. Add Book");
            System.out.println("2. Display Books");
            System.out.println("3. Search Book by Title");
            System.out.println("4. Delete Book by ID");
            System.out.println("5. Update Book by ID");
            System.out.println("6. Search Book by ID");
            System.out.println("7. Search Book by Author");
            System.out.println("8. Exit");
            System.out.println("---------------------------------------------");
            System.out.print("Enter your choice: ");
            choice = sc.nextInt();

            switch (choice) {
                case 1:
                    System.out.print("Enter Book ID: ");
                    id = sc.nextInt();
                    sc.nextLine(); // consume newline
                    System.out.print("Enter Title: ");
                    title = sc.nextLine();
                    System.out.print("Enter Author: ");
                    author = sc.nextLine();
                    lib.addBook(id, title, author);
                    break;
                case 2:
                    lib.displayBooks();
                    break;
                case 3:
                    sc.nextLine(); // clear buffer
                    System.out.print("Enter title to search: ");
                    title = sc.nextLine();
                    lib.searchBook(title);
                    break;
                case 4:
                    System.out.print("Enter Book ID to delete: ");
                    id = sc.nextInt();
                    lib.deleteBook(id);
                    break;
                case 5:
                    System.out.print("Enter Book ID to update: ");
                    id = sc.nextInt();
                    lib.updateBook(id, sc);
                    break;
                case 6:
                    System.out.print("Enter Book ID to Search: ");
                    id = sc.nextInt();
                    lib.searchBookById(id);
                    break;
                case 7:
                System.out.print("Enter author name to Search: ");
                 author=sc.next();
                 lib.searchBookByAuthor(author);
                 break;
                case 8:
                    System.out.println("Exiting program.");
                    break;
                default:
                    System.out.println("Invalid choice!");
            }
        } while (choice != 8);

        sc.close();
    }
}