Question

Can someone please help me add appropriate descriptive comments to each line of code in the project explaining why the code is in the application.

import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

public class BookManager {
private List<Book> bookList;
  
public BookManager() {
bookList = new BookCatalog().getCatalog();
}
  
public List<Book> getBooks(Predicate<Book> condition) {
List<Book> books = new ArrayList<>();
for (Book b: bookList) {
if (condition.test(b)) {
books.add(b);
}
}
return books;
}
}

import java.util.List;

public class BookManagerApp {

public static void main(String[] args) {
BookManager manager = new BookManager();
  
List<Book> booksByTitle = manager.getBooks(
b -> b.getTitle().contains("Java"));
System.out.println("\nBOOKS BY TITLE:");
printList(booksByTitle);
  
List<Book> booksByCategory = manager.getBooks(
b -> b.getCategory().equals(Book.JAVA));
System.out.println("\nBOOKS BY CATEGORY:");
printList(booksByCategory);
  
List<Book> booksByFormat = manager.getBooks(
b -> b.getFormat().equals(Book.PAPERBACK));
System.out.println("\nBOOKS BY FORMAT:");
printList(booksByFormat);
}
  
public static void printList(List<Book> bookList) {
for (Book b : bookList) {
System.out.println(b);
}
}
}

Answer 1

import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

public class BookManager {
// create a list to store the Book objects
private List<Book> bookList;
// In constructor creating the list of books by calling the getCatalog
public BookManager() {
// getting the list of books from the catalog
bookList = new BookCatalog().getCatalog();
}
  
// return the list of all books as List
public List<Book> getBooks(Predicate<Book> condition) {
List<Book> books = new ArrayList<>();
//iterating the List and checking the condition
for (Book b: bookList) {
// if condition is met than add it to result
if (condition.test(b)) {
   //adding to another list
books.add(b);
}
}
//returning the list
return books;
}
}

import java.util.List;

public class BookManagerApp {

public static void main(String[] args) {
BookManager manager = new BookManager();

// here we are filter the books using the contains function so now
// it will hold the books which are related to java
List<Book> booksByTitle = manager.getBooks(
b -> b.getTitle().contains("Java"));
System.out.println("\nBOOKS BY TITLE:");
printList(booksByTitle);
// here we are filter the books using the contains function so now
// it will hold the books which are related to java category
List<Book> booksByCategory = manager.getBooks(
b -> b.getCategory().equals(Book.JAVA));
System.out.println("\nBOOKS BY CATEGORY:");
printList(booksByCategory);

// here we are filter the books using the contains function so now
// it will hold the books which are related to same format
List<Book> booksByFormat = manager.getBooks(
b -> b.getFormat().equals(Book.PAPERBACK));
System.out.println("\nBOOKS BY FORMAT:");
printList(booksByFormat);
}
  
public static void printList(List<Book> bookList) {
// iterating the list and printing the each book
for (Book b : bookList) {
System.out.println(b);
}
}
}