Author.java

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "authors")
public class Author {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String name;

    @ManyToMany(fetch = FetchType.LAZY)
    private List<Book> books;

    // Getters / Setters...
}

Book.java

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "books")
public class Book {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long id;

    private String name;

    private String isbn;

    @ManyToMany(mappedBy = "books", fetch = FetchType.LAZY)
    private List<Author> authors;

    // Getters / Setters...
}