content: package com.bookstore;
  
  import com.bookstore.dto.AuthorNameAge;
  import com.bookstore.service.BookstoreService;
  
  import org.springframework.boot.ApplicationRunner;
  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;
  import org.springframework.context.annotation.Bean;
  
  import java.util.List;
  
  @SpringBootApplication
  public class MainApplication {
      private final BookstoreService bookstoreService;
  
      public MainApplication(BookstoreService bookstoreService) {
          this.bookstoreService = bookstoreService;
      }
  
      public static void main(String[] args) {
          SpringApplication.run(MainApplication.class, args);
      }
  
      @Bean
      public ApplicationRunner init() {
          return args -> {
              List<AuthorNameAge> authors = bookstoreService.fetchAuthorsNamesAndAges();
              System.out.println("Number of authors:" + authors.size());
  
              for (AuthorNameAge author : authors) {
                  System.out.println("Author name: " + author.getName()
                          + " | Age: " + author.getAge());
              }
  
              System.out.println("============================================");
  
              List<String> names = bookstoreService.fetchAuthorsNames();
              System.out.println("Number of items:" + names.size());
              System.out.println(names);
          };
      }
  }