Build a Library Book Manager in Java

PROBLEM UNDERSTANDING

Input and expected output

No input required

Java Basics

COMPLETE JAVA 17 PROGRAM

Complete Java 17 implementation

import java.util.*;record Book(String isbn,String title){}class Library{private final Map<String,Book> books=new LinkedHashMap<>();void add(Book book){books.put(book.isbn(),book);}Optional<Book> find(String isbn){return Optional.ofNullable(books.get(isbn));}}class Main{public static void main(String[] args){Library library=new Library();library.add(new Book("101","Java Basics"));System.out.println(library.find("101").map(Book::title).orElse("Not found"));}}

PROGRAM EXPLANATION

Algorithm and explanation

1. Initialize the deterministic sample values used for build a library book manager in java.
2. Create the required object and apply Repository pattern and Optional to its state or behavior.
3. Print the final result and compare it with the documented sample output.

This Java 17 example demonstrates Repository pattern, Optional, and Map through a complete, executable program. The values are intentionally small so students can trace each statement, verify the output, and then modify the example safely in the online compiler.

EFFICIENCY

Time and space complexity

DEBUGGING CHECKLIST

Common mistakes

Try it yourself