feat: adds Lesson 10 homework assignment and stretch requirement.

lesson_10/README.md

@@ -18,6 +18,14 @@
 * Read HFDP 1-2.
 * Complete [Applying SOLID principles](#applying-solid-principles) exercise.
 
-## Applying SOLID Principles
+## Applying SOLID Principles (Library Management System, Part II)
 
-* TODO(anthonydmays): Add details
+In this assignment, you will be given starting implementations for the `Library`, `Book`, and `Patron` classes. You will need to add the following enhancements to support new functionality:
+
+* We now want to support the concept of a `Librarian`. A librarian should be able to check out or check in books just like other patrons. Books can no longer be added or removed from the `Library` without a librarian.
+* We also want to support other types of media formats, including `Dvd`, `Magazine`, and `Newspaper` types. Patrons cannot check out `Magazine` or `Newspaper` items.
+* [Stretch] Add the ability to search for items in the library by title, ISBN, author, or type. Extra credit will not be assigned unless the previous requirements have been met.
+
+You will need to make changes to code in the [solid/][solid-folder] sub-folder and submit your PR for credit. Don't forget to follow the Conventional Commit spec for your commit messages and pull requests title and descriptions.
+
+[solid-folder]: ./solid/

lesson_10/solid/solid_app/src/main/java/com/codedifferently/lesson10/library/Book.java

@@ -0,0 +1,104 @@
+package com.codedifferently.lesson10.library;
+
+import com.codedifferently.lesson10.library.exceptions.LibraryNotSetException;
+import com.codedifferently.lesson10.library.exceptions.WrongLibraryException;
+import java.util.List;
+import java.util.Objects;
+
+/** Represents a book. */
+public class Book {
+ private Library library;
+ private String title;
+ private String isbn;
+ private List<String> authors;
+ private int numberOfPages;
+
+ /**
+ * Create a new book with the given title, ISBN, authors, and number of pages.
+ *
+ * @param title The title of the book.
+ * @param isbn The ISBN of the book.
+ * @param authors The authors of the book.
+ * @param numberOfPages The number of pages in the book.
+ */
+ public Book(String title, String isbn, List<String> authors, int numberOfPages) {
+ this.title = title;
+ this.isbn = isbn;
+ this.authors = authors;
+ this.numberOfPages = numberOfPages;
+ }
+
+ /**
+ * Get the id of the book.
+ *
+ * @return The id of the book.
+ */
+ public String getId() {
+ return this.isbn;
+ }
+
+ /**
+ * Get the library that the book is in.
+ *
+ * @param library The library that the book is in.
+ * @throws WrongLibraryException If the book is not in the library.
+ */
+ public void setLibrary(Library library) throws WrongLibraryException {
+ if (library != null && !library.hasBook(this)) {
+ throw new WrongLibraryException(
+ "Book " + this.getId() + " is not in library " + library.getId());
+ }
+ this.library = library;
+ }
+
+ /** Get the title of the book. */
+ public String getTitle() {
+ return title;
+ }
+
+ /** Get the ISBN of the book. */
+ public String getIsbn() {
+ return isbn;
+ }
+
+ /** Get the authors of the book. */
+ public List<String> getAuthors() {
+ return authors;
+ }
+
+ /** Get the number of pages in the book. */
+ public int getNumberOfPages() {
+ return numberOfPages;
+ }
+
+ /**
+ * Check if the book is checked out.
+ *
+ * @return True if the book is checked out, false otherwise.
+ * @throws LibraryNotSetException If the library is not set for the book.
+ */
+ public boolean isCheckedOut() throws LibraryNotSetException {
+ if (this.library == null) {
+ throw new LibraryNotSetException("Library not set for book " + this.getId());
+ }
+ return library.isCheckedOut(this);
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) return true;
+ if (!(o instanceof Book)) return false;
+ Book book = (Book) o;
+ return Objects.equals(getIsbn(), book.getIsbn());
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(getId());
+ }
+
+ @Override
+ public String toString() {
+ return "Book{" + "id='" + getId() + '\'' + ", title='" + getTitle() + '\'' + '}';
+ }
+}

lesson_10/solid/solid_app/src/main/java/com/codedifferently/lesson10/library/Library.java

@@ -0,0 +1,181 @@
+package com.codedifferently.lesson10.library;
+
+import com.codedifferently.lesson10.library.exceptions.BookCheckedOutException;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+/** Represents a library. */
+public class Library {
+ private Set<String> bookIds = new HashSet<>();
+ private Set<String> checkedOutIsbns = new HashSet<>();
+ private Map<String, Set<Book>> checkedOutBooksByPatron = new HashMap<>();
+ private Set<String> patronIds = new HashSet<>();
+ private String id;
+
+ /**
+ * Create a new library with the given id.
+ *
+ * @param id The id of the library.
+ */
+ public Library(String id) {
+ this.id = id;
+ }
+
+ /**
+ * Get the id of the library.
+ *
+ * @return The id of the library.
+ */
+ public String getId() {
+ return this.id;
+ }
+
+ /**
+ * Add a book to the library.
+ *
+ * @param book The book to add.
+ */
+ public void addBook(Book book) {
+ this.bookIds.add(book.getId());
+ book.setLibrary(this);
+ }
+
+ /**
+ * Remove a book from the library.
+ *
+ * @param book The book to remove.
+ */
+ public void removeBook(Book book) throws BookCheckedOutException {
+ if (this.isCheckedOut(book)) {
+ throw new BookCheckedOutException("Cannot remove checked out book.");
+ }
+ this.bookIds.remove(book.getId());
+ book.setLibrary(null);
+ }
+
+ /**
+ * Add a patron to the library.
+ *
+ * @param patron The patron to add.
+ */
+ public void addPatron(Patron patron) {
+ this.patronIds.add(patron.getId());
+ this.checkedOutBooksByPatron.put(patron.getId(), new HashSet<>());
+ patron.setLibrary(this);
+ }
+
+ /**
+ * Remove a patron from the library.
+ *
+ * @param patron The patron to remove.
+ */
+ public void removePatron(Patron patron) throws BookCheckedOutException {
+ if (this.checkedOutBooksByPatron.get(patron.getId()).size() > 0) {
+ throw new BookCheckedOutException("Cannot remove patron with checked out books.");
+ }
+ this.patronIds.remove(patron.getId());
+ this.checkedOutBooksByPatron.remove(patron.getId());
+ patron.setLibrary(null);
+ }
+
+ /**
+ * Check out a book to a patron.
+ *
+ * @param book The book to check out.
+ * @param patron The patron to check out the book to.
+ * @return True if the book was checked out, false otherwise.
+ */
+ public boolean checkOutBook(Book book, Patron patron) {
+ if (!this.canCheckOutBook(book, patron)) {
+ return false;
+ }
+ this.checkedOutIsbns.add(book.getIsbn());
+ this.checkedOutBooksByPatron.get(patron.getId()).add(book);
+ return true;
+ }
+
+ private boolean canCheckOutBook(Book book, Patron patron) {
+ if (!this.hasBook(book)) {
+ return false;
+ }
+ if (this.isCheckedOut(book)) {
+ return false;
+ }
+ if (!this.hasPatron(patron)) {
+ return false;
+ }
+ return true;
+ }
+
+ /**
+ * Check if the library has the given book.
+ *
+ * @param book The book to check for.
+ * @return True if the library has the book, false otherwise.
+ */
+ public boolean hasBook(Book book) {
+ return this.bookIds.contains(book.getId());
+ }
+
+ /**
+ * Check if the given book is checked out.
+ *
+ * @param book The book to check.
+ * @return True if the book is checked out, false otherwise.
+ */
+ public boolean isCheckedOut(Book book) {
+ return this.checkedOutIsbns.contains(book.getIsbn());
+ }
+
+ /**
+ * Check if the library has the given patron.
+ *
+ * @param patron The patron to check for.
+ * @return True if the library has the patron, false otherwise.
+ */
+ public boolean hasPatron(Patron patron) {
+ return this.patronIds.contains(patron.getId());
+ }
+
+ /**
+ * Return a book to the library.
+ *
+ * @param book The book to return.
+ * @param patron The patron returning the book.
+ * @return True if the book was returned, false otherwise.
+ */
+ public boolean checkInBook(Book book, Patron patron) {
+ if (!this.hasBook(book)) {
+ return false;
+ }
+ this.checkedOutIsbns.remove(book.getIsbn());
+ this.checkedOutBooksByPatron.get(patron.getId()).remove(book);
+ return true;
+ }
+
+ /**
+ * Get the books checked out by a patron.
+ *
+ * @param patron The patron to get the books for.
+ * @return The books checked out by the patron.
+ */
+ public Set<Book> getCheckedOutByPatron(Patron patron) {
+ return this.checkedOutBooksByPatron.get(patron.getId());
+ }
+
+ @Override
+ public String toString() {
+ return "Library{"
+ + "bookIds="
+ + bookIds
+ + ", checkedOutIsbns="
+ + checkedOutIsbns
+ + ", checkedOutBooksByPatron="
+ + checkedOutBooksByPatron
+ + ", patronIds="
+ + patronIds
+ + '}';
+ }
+}

lesson_10/solid/solid_app/src/main/java/com/codedifferently/lesson10/library/Patron.java

@@ -0,0 +1,79 @@
+package com.codedifferently.lesson10.library;
+
+import com.codedifferently.lesson10.library.exceptions.LibraryNotSetException;
+import com.codedifferently.lesson10.library.exceptions.WrongLibraryException;
+import java.util.Objects;
+import java.util.Set;
+
+/** Represents a patron of a library. */
+public class Patron {
+ private Library library;
+ private String name;
+ private String email;
+
+ /**
+ * Create a new patron with the given name and email.
+ *
+ * @param name The name of the patron.
+ * @param email The email of the patron.
+ */
+ public Patron(String name, String email) {
+ this.name = name;
+ this.email = email;
+ }
+
+ /**
+ * Get the library that the patron is in.
+ *
+ * @param library The library that the patron is in.
+ * @throws WrongLibraryException If the patron is not in the library.
+ */
+ public void setLibrary(Library library) throws WrongLibraryException {
+ if (library != null && !library.hasPatron(this)) {
+ throw new WrongLibraryException(
+ "Patron " + this.getId() + " is not in library " + library.getId());
+ }
+ this.library = library;
+ }
+
+ /** Get the name of the patron. */
+ public String getName() {
+ return this.name;
+ }
+
+ /** Get the email of the patron. */
+ public String getId() {
+ return this.email;
+ }
+
+ /**
+ * Gets the books currently checked out to the patron.
+ *
+ * @return The books currently checked out to the patron.
+ * @throws LibraryNotSetException If the library is not set for the patron.
+ */
+ public Set<Book> getCheckedOutBooks() throws LibraryNotSetException {
+ if (this.library == null) {
+ throw new LibraryNotSetException("Library not set for patron " + this.getId());
+ }
+ return this.library.getCheckedOutByPatron(this);
+ }
+
+ @Override
+ public boolean equals(Object o) {
+ if (this == o) return true;
+ if (!(o instanceof Patron)) return false;
+ Patron patron = (Patron) o;
+ return Objects.equals(getId(), patron.getId());
+ }
+
+ @Override
+ public int hashCode() {
+ return Objects.hash(getId());
+ }
+
+ @Override
+ public String toString() {
+ return "Patron{" + "id='" + getId() + '\'' + ", name='" + getName() + '\'' + '}';
+ }
+}

lesson_10/solid/solid_app/src/main/java/com/codedifferently/lesson10/library/exceptions/BookCheckedOutException.java

@@ -0,0 +1,7 @@
+package com.codedifferently.lesson10.library.exceptions;
+
+public class BookCheckedOutException extends RuntimeException {
+ public BookCheckedOutException(String message) {
+ super(message);
+ }
+}

lesson_10/solid/solid_app/src/main/java/com/codedifferently/lesson10/library/exceptions/LibraryNotSetException.java

@@ -0,0 +1,7 @@
+package com.codedifferently.lesson10.library.exceptions;
+
+public class LibraryNotSetException extends RuntimeException {
+ public LibraryNotSetException(String message) {
+ super(message);
+ }
+}