Java case

study
A.Hrushikesh varma

2023002077
The Library Management System is a simple,
yet effective Java-based application designed to
manage books and members in a library. It
allows librarians to add books, register
members, track book borrowing, and
display records while ensuring data integrity
through exception handling.
CODE:
import java.util.Scanner;

class LibraryItem {
protected String title;
protected int itemId;

public LibraryItem(String title, int itemId) {

this.title = title;
this.itemId = itemId;
}

public void displayDetails() {

 System.out.println("Title: " + title + ", Item ID: " + itemId);
}
}

interface Borrowable {
boolean borrowItem(int quantity);
}

class Book extends LibraryItem implements Borrowable {

private String author;
private int stock;

public Book(String title, int itemId, String author, int stock)

throws StockException {
super(title, itemId);
if (stock < 0) {
throw new StockException("Stock cannot be negative.");
}
this.author = author;
this.stock = stock;
}

@Override
public void displayDetails() {
super.displayDetails();
System.out.println("Author: " + author + ", Stock: " +
stock);
}
 @Override
public boolean borrowItem(int quantity) {
if (quantity <= stock) {
stock -= quantity;
return true;
}
return false;
}
}

class StockException extends Exception {

public StockException(String message) {
super(message);
}
}

class Member {
private int memberId;
private String name;
private int age;

public Member(int memberId, String name, int age) throws

InvalidMemberException {
if (!name.matches("[a-zA-Z ]+") || age < 16 || age > 100)
{
 throw new InvalidMemberException("Invalid member
details: Name should only contain letters, and age should be
between 16 and 100.");
}
this.memberId = memberId;
this.name = name;
this.age = age;
}

public void printMemberInfo() {

System.out.println("Member ID: " + memberId + ", Name:
" + name + ", Age: " + age);
}
}

class InvalidMemberException extends Exception {

public InvalidMemberException(String message) {
super(message);
}
}

public class LibraryManagement {

private static Book[] books = new Book[5];
private static Member[] members = new Member[3];
private static int bookCount = 0;
private static int memberCount = 0;

public static Book searchBookByTitle(String title) {

 for (Book book : books) {
if (book != null && book.title.equalsIgnoreCase(title)) {
return book;
}
}
return null;
}

public static void main(String[] args) {

Scanner scanner = new Scanner(System.in);
int choice;

do {
System.out.println("\nLibrary Management System");
System.out.println("1. Add a book");
System.out.println("2. Register a member");
System.out.println("3. Borrow a book");
System.out.println("4. Display all books and members");
System.out.println("5. Exit");
System.out.print("Enter your choice: ");
choice = scanner.nextInt();
scanner.nextLine();

switch (choice) {
case 1:
if (bookCount < books.length) {
System.out.print("Enter book title: ");
 String title = scanner.nextLine();
System.out.print("Enter item ID: ");
int itemId = scanner.nextInt();
scanner.nextLine();
System.out.print("Enter author: ");
String author = scanner.nextLine();
System.out.print("Enter stock: ");
int stock = scanner.nextInt();
try {
books[bookCount++] = new Book(title,
itemId, author, stock);
} catch (StockException e) {
System.out.println(e.getMessage());
}
} else {
System.out.println("Book storage full!");
}
break;
case 2:
if (memberCount < members.length) {
System.out.print("Enter member ID: ");
int memberId = scanner.nextInt();
scanner.nextLine();
System.out.print("Enter name: ");
String name = scanner.nextLine();
System.out.print("Enter age: ");
int age = scanner.nextInt();
 try {
members[memberCount++] = new
Member(memberId, name, age);
} catch (InvalidMemberException e) {
System.out.println(e.getMessage());
}
} else {
System.out.println("Member storage full!");
}
break;
case 3:
System.out.print("Enter book title: ");
String title = scanner.nextLine();
System.out.print("Enter quantity: ");
int quantity = scanner.nextInt();
Book book = searchBookByTitle(title);
if (book != null && book.borrowItem(quantity)) {
System.out.println("Book borrowed
successfully!");
} else {
System.out.println("Book not available or
insufficient stock.");
}
break;
case 4:
System.out.println("\nBooks:");
for (Book b : books) {
if (b != null) b.displayDetails();
 }
System.out.println("\nMembers:");
for (Member m : members) {
if (m != null) m.printMemberInfo();
}
break;
case 5:
System.out.println("Exiting...");
break;
default:
System.out.println("Invalid choice!");
}
} while (choice != 5);
scanner.close();
}
}

OUTPUT: