Book.java

package org.adoptopenjdk.lambda.tutorial.exercise3;

/*
 * #%L
 * lambda-tutorial
 * %%
 * Copyright (C) 2013 Adopt OpenJDK
 * %%
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as
 * published by the Free Software Foundation, either version 2 of the 
 * License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public 
 * License along with this program.  If not, see
 * <http://www.gnu.org/licenses/gpl-2.0.html>.
 * #L%
 */

/**
 * Class representing a book
 */
public final class Book {
    
    private final String title;
    private final Author author;
    private final Publisher publisher;

    public Book(String title, Author author, Publisher publisher) {
        this.title = title;
        this.author = author;
        this.publisher = publisher;
    }

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

        Book book = (Book) o;

        if (!author.equals(book.getAuthor())) return false;
        if (!publisher.equals(book.getPublisher())) return false;
        if (!title.equals(book.getTitle())) return false;

        return true;
    }

    @Override
    public int hashCode() {
        int result = title.hashCode();
        result = 31 * result + author.hashCode();
        result = 31 * result + publisher.hashCode();
        return result;
    }

    public String getTitle() {
        return title;
    }

    public Author getAuthor() {
        return author;
    }

    public Publisher getPublisher() {
        return publisher;
    }
}