Immutables Library Examples

import org.immutables.value.Value;

import java.util.List;
import java.util.Optional;

@Value.Immutable
public interface Book {
    String title();

    Optional<String> excerpt();

    Float price();

    List<String> tags();

}

import org.immutables.value.Value;

import java.util.List;

@Value.Immutable
public interface Library {
    String name();

    List<Book> books();

    boolean opened();
}

public class AppTest {

    public static void main(final String[] args) {
        Book book1 = ImmutableBook.builder()
                .title("One first book")
                .excerpt("Lorem ipsum dolor sit.")
                .addTags("foo", "bar", "baz")
                .price(12.5F)
                .build();

        Book book2 = ImmutableBook.builder()
                .title("Another book")
                .addTags("xoxo", "trololol")
                .price(20.2F)
                .build();

        Library library = ImmutableLibrary.builder()
                .name("My first library")
                .opened(true)
                .addBooks(book1, book2)
                .build();

        System.out.println(library.toString());
    }
}