@Override
  public Map<Reader, List<Book>> findAllWithBooks() {
    var selectAllReadersWithBooks =
        """
                SELECT reader.id, reader.name, book.name AS bookName, book.author AS authorName
                FROM reader LEFT JOIN book ON reader.id = book.reader_id
                """;
    try (var connection = DBUtil.getConnection();
        var selectAllReadersWithBooksStatement = connection.createStatement()) {
      var resultSet = selectAllReadersWithBooksStatement.executeQuery(selectAllReadersWithBooks);
      Map<Reader, List<Book>> map = new HashMap<>();
      while (resultSet.next()) {
        var book = new Book(resultSet.getString("bookName"), resultSet.getString("authorName"));
        map.computeIfAbsent(mapResultSetToReader(resultSet), k -> new ArrayList<>()).add(book);
      }
      return map;
    } catch (SQLException e) {
      throw new DaoOperationException("Error finding readers with borrowed books list!");
    }
  }

 private void showAllReadersWithBorrowedBooks() {
    Map<Reader, List<Book>> map = libraryService.findAllReadersWithBooks();
    map.forEach(
        (reader, books) -> {
          if (books.get(0).getName() == null) {
            System.out.println(
                reader.getName()
                    + ":"
                    + SET_GREEN_TEXT_COLOR
                    + "no books borrowed"
                    + SET_DEFAULT_TEXT_COLOR);
          } else {
            System.out.print(SET_GREEN_TEXT_COLOR + reader.getName() + ": ");
            var booksInfo =
                books.stream()
                    .map(book -> SET_GREEN_TEXT_COLOR + book.getName() + " by " + book.getAuthor())
                    .collect(Collectors.joining(", "));
            System.out.println(booksInfo + SET_DEFAULT_TEXT_COLOR);
          }
        });
  }
package entity;

import java.util.Objects;

public class Book {
  private long id;
  private String name;
  private  String author;
  private long readerId;

  public Book(String name, String author) {
    this.name = name;
    this.author = author;
  }

  public Book() {
  }

  public void setReaderId(long readerId) {
    this.readerId = readerId;
  }

  public void setId(long id) {
    this.id = id;
  }

  public void setName(String name) {
    this.name = name;
  }

  public void setAuthor(String author) {
    this.author = author;
  }

  public String getName() {
    return name;
  }

  public String getAuthor() {
    return author;
  }

  @Override
  public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;
    Book book = (Book) o;
    return id == book.id;
  }

  @Override
  public int hashCode() {
    return Objects.hash(id);
  }

  @Override
  public String toString() {
    return "Book{"
        + "id="
        + id
        + ", name='"
        + name
        + '\''
        + ", author='"
        + author
        + '\''
        + ", readerId="
        + readerId
        + '}';
  }
}