feat: Creating a Library Management System containing related classes and tests

lesson_09/oop/oop_app/src/main/java/com/codedifferently/lesson9/LibraryManagementSystem/Book.java

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+package com.codedifferently.lesson9.LibraryManagementSystem;
+
+/** Represents a book in the library. */
+public class Book {
+ private String title;
+ private String author;
+ private String isbn;
+ private int numberOfPages;
+ private boolean checkedOut;
+
+ /**
+ * Constructs a new Book instance with the given parameters.
+ *
+ * @param title The title of the book.
+ * @param isbn The ISBN of the book.
+ * @param author The author(s) of the book.
+ * @param numberOfPages The number of pages in the book.
+ */
+ public Book(String title, String isbn, String author, int numberOfPages) {
+ this.title = title;
+ this.isbn = isbn;
+ this.author = author;
+ this.numberOfPages = numberOfPages;
+ this.checkedOut = false; // Initially, the book is not checked out
+ }
+
+ /**
+ * Gets the author(s) of the book.
+ *
+ * @return The author(s) of the book.
+ */
+ public String getAuthor() {
+ return author;
+ }
+
+ /**
+ * Sets the author(s) of the book.
+ *
+ * @param author The author(s) of the book.
+ */
+ public void setAuthor(String author) {
+ this.author = author;
+ }
+
+ /**
+ * Gets the ISBN of the book.
+ *
+ * @return The ISBN of the book.
+ */
+ public String getIsbn() {
+ return isbn;
+ }
+
+ /**
+ * Sets the ISBN of the book.
+ *
+ * @param isbn The ISBN of the book.
+ */
+ public void setIsbn(String isbn) {
+ this.isbn = isbn;
+ }
+
+ /**
+ * Gets the number of pages in the book.
+ *
+ * @return The number of pages in the book.
+ */
+ public int getNumberOfPages() {
+ return numberOfPages;
+ }
+
+ /**
+ * Sets the number of pages in the book.
+ *
+ * @param numberOfPages The number of pages in the book.
+ */
+ public void setNumberOfPages(int numberOfPages) {
+ this.numberOfPages = numberOfPages;
+ }
+
+ /**
+ * Gets the title of the book.
+ *
+ * @return The title of the book.
+ */
+ public String getTitle() {
+ return title;
+ }
+
+ /**
+ * Sets the title of the book.
+ *
+ * @param title The title of the book.
+ */
+ public void setTitle(String title) {
+ this.title = title;
+ }
+
+ /**
+ * Checks if the book is currently checked out.
+ *
+ * @return True if the book is checked out, false otherwise.
+ */
+ public boolean isCheckedOut() {
+ return checkedOut;
+ }
+
+ /**
+ * Sets the checked out status of the book.
+ *
+ * @param checkedOut True if the book is to be checked out, false otherwise.
+ */
+ public void setCheckedOut(boolean checkedOut) {
+ this.checkedOut = checkedOut;
+ }
+}

lesson_09/oop/oop_app/src/main/java/com/codedifferently/lesson9/LibraryManagementSystem/Library.java

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+package com.codedifferently.lesson9.LibraryManagementSystem;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Represents a library that manages a collection of books and patrons. */
+public class Library {
+ private List<Book> books;
+ private List<Patron> patrons;
+
+ /** Constructs a new Library instance with empty collections of books and patrons. */
+ public Library() {
+ this.books = new ArrayList<>();
+ this.patrons = new ArrayList<>();
+ }
+
+ /**
+ * Adds a book to the library's collection.
+ *
+ * @param book The book to be added.
+ */
+ public void addBook(Book book) {
+ books.add(book);
+ }
+
+ /**
+ * Removes a book from the library's collection.
+ *
+ * @param book The book to be removed.
+ */
+ public void removeBook(Book book) {
+ books.remove(book);
+ }
+
+ /**
+ * Registers a new patron with the library.
+ *
+ * @param patron The patron to be registered.
+ */
+ public void registerPatron(Patron patron) {
+ patrons.add(patron);
+ }
+
+ /**
+ * Checks out a book to a patron.
+ *
+ * @param book The book to be checked out.
+ * @param patron The patron who is checking out the book.
+ */
+ public void checkOutBook(Book book, Patron patron) {
+ if (!books.contains(book)) {
+ throw new IllegalArgumentException("Book not found in the library");
+ }
+ if (!patrons.contains(patron)) {
+ throw new IllegalArgumentException("Patron not registered in the library");
+ }
+ if (book.isCheckedOut()) {
+ throw new IllegalStateException("Book is already checked out");
+ }
+ book.setCheckedOut(true);
+ patron.addCheckedOutBook(book);
+ }
+
+ /**
+ * Returns a book that was checked out by a patron.
+ *
+ * @param book The book to be returned.
+ * @param patron The patron who is returning the book.
+ */
+ public void returnBook(Book book, Patron patron) {
+ if (!books.contains(book)) {
+ throw new IllegalArgumentException("Book not found in the library");
+ }
+ if (!patrons.contains(patron)) {
+ throw new IllegalArgumentException("Patron not registered in the library");
+ }
+ if (!book.isCheckedOut()) {
+ throw new IllegalStateException("Book is not checked out");
+ }
+ book.setCheckedOut(false);
+ patron.removeCheckedOutBook(book);
+ }
+
+ /**
+ * Gets the list of books in the library.
+ *
+ * @return The list of books in the library.
+ */
+ public List<Book> getBooks() {
+ return books;
+ }
+
+ /**
+ * Gets the list of patrons registered in the library.
+ *
+ * @return The list of patrons registered in the library.
+ */
+ public List<Patron> getPatrons() {
+ return patrons;
+ }
+}

lesson_09/oop/oop_app/src/main/java/com/codedifferently/lesson9/LibraryManagementSystem/Patron.java

@@ -0,0 +1,65 @@
+package com.codedifferently.lesson9.LibraryManagementSystem;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/** Represents a patron of the library. */
+public class Patron {
+ private String name;
+ private List<Book> checkedOutBooks;
+
+ /**
+ * Constructs a new Patron instance with the given name.
+ *
+ * @param name The name of the patron.
+ */
+ public Patron(String name) {
+ this.name = name;
+ this.checkedOutBooks = new ArrayList<>();
+ }
+
+ /**
+ * Gets the name of the patron.
+ *
+ * @return The name of the patron.
+ */
+ public String getName() {
+ return name;
+ }
+
+ /**
+ * Sets the name of the patron.
+ *
+ * @param name The name of the patron.
+ */
+ public void setName(String name) {
+ this.name = name;
+ }
+
+ /**
+ * Gets the list of books checked out by the patron.
+ *
+ * @return The list of checked out books.
+ */
+ public List<Book> getCheckedOutBooks() {
+ return checkedOutBooks;
+ }
+
+ /**
+ * Adds a book to the list of books checked out by the patron.
+ *
+ * @param book The book to be added.
+ */
+ public void addCheckedOutBook(Book book) {
+ checkedOutBooks.add(book);
+ }
+
+ /**
+ * Removes a book from the list of books checked out by the patron.
+ *
+ * @param book The book to be removed.
+ */
+ public void removeCheckedOutBook(Book book) {
+ checkedOutBooks.remove(book);
+ }
+}

lesson_09/oop/oop_app/src/test/java/com/codedifferently/lesson9/LibraryManagementSystemTest/BookTest.java

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+package com.codedifferently.lesson9.LibraryManagementSystemTest;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import com.codedifferently.lesson9.LibraryManagementSystem.Book;
+import org.junit.jupiter.api.Test;
+
+/** Test class for the {@link com.codedifferently.lesson9.LibraryManagementSystem.Book} class. */
+public class BookTest {
+
+ /** Test the constructor of the Book class. */
+ @Test
+ public void testBookConstructor() {
+ // Arrange
+ String title = "The Pragmatic Programmer";
+ String isbn = "9780135957059";
+ String author = "David Thomas, Andrew Hunt";
+ int numberOfPages = 320;
+
+ // Act
+ Book book = new Book(title, isbn, author, numberOfPages);
+
+ // Assert
+ assertEquals(title, book.getTitle());
+ assertEquals(isbn, book.getIsbn());
+ assertEquals(author, book.getAuthor());
+ assertEquals(numberOfPages, book.getNumberOfPages());
+ }
+}

lesson_09/oop/oop_app/src/test/java/com/codedifferently/lesson9/LibraryManagementSystemTest/LibraryTest.java

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+package com.codedifferently.lesson9.LibraryManagementSystemTest;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.codedifferently.lesson9.LibraryManagementSystem.Book;
+import com.codedifferently.lesson9.LibraryManagementSystem.Library;
+import com.codedifferently.lesson9.LibraryManagementSystem.Patron;
+import java.util.List;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+public class LibraryTest {
+ private Library library;
+ private Book book;
+ private Patron patron;
+
+ @BeforeEach
+ public void setUp() {
+ library = new Library();
+ book = new Book("The Pragmatic Programmer", "9780135957059", "David Thomas, Andrew Hunt", 320);
+ // Add the book to the library
+ library.addBook(book);
+ patron = new Patron("John Doe");
+ library.registerPatron(patron);
+ }
+
+ @Test
+ public void testAddBook() {
+ List<Book> books = library.getBooks();
+ assertEquals(1, books.size());
+ assertEquals(book, books.get(0));
+ }
+
+ @Test
+ public void testRemoveBook() {
+ library.removeBook(book);
+ List<Book> books = library.getBooks();
+ assertEquals(0, books.size());
+ }
+
+ @Test
+ public void testCheckOutBook() {
+ library.checkOutBook(book, patron);
+ assertTrue(book.isCheckedOut());
+ assertTrue(patron.getCheckedOutBooks().contains(book));
+ }
+
+ @Test
+ public void testReturnBook() {
+ library.checkOutBook(book, patron);
+ library.returnBook(book, patron);
+ assertFalse(book.isCheckedOut());
+ assertFalse(patron.getCheckedOutBooks().contains(book));
+ }
+}