Print specific element of an arraylist in Java based on a given parameter

There's this task I'm working on, in which I have to make an arraylist based on an Author class, which has as its properties: ID, author's name, book and nationality. This aside, I had to make another class, which receives as a parameter the ID, and returns the corresponding author's info. My problem is that I wrote the code, but no matter what ID my input receives, it always retrieves the same author's information. Could anyone help me on this?

Author.java

public class Author {
    
    private int id;
    private String name;
    private string book;
    private string country;
    
    public Author(int id, String name, String book, String country) {
        this.id = id;
        this.name = name;
        this.book = book;
        this.country = country;
    }
    
    public int getId() {
        return id;
    }

    public String getName() {
        return name;
    }
    
    public int getBook() {
        return book;
    }

    public int getCountry() {
        return country;
    }
    
    @Override
    public String toString() {
        return "Id: " + this.id + ", Name: " + this.name + ", Book:" + this.book + ", Country:" + this.country;
    }
}

GetAuthor.java (class used to retrieve Author's info based on the ID)

public class GetAuthor {
    
    public Author returnAuthor(int id, ArrayList<Author> list) {
        
        Author author = null;
        id = 0;
        for (int i = 0 ; i < list.size() ; i++) {
            if(author == null || author(i).getId() == id) {
                author = list.get(i);
                id = list.get(i).getId();
            }
        }
        return author;  
    }
}

Main.java

public class Main {

    public static void main(String[] args) {
             
        Author w1 = new Author(1, "Franz Kafka", " The Metamorphosis", "Austria");
        Author w2 = new Author(2, "Neil Gaiman", "Sandman", "England");
        Author w3 = new Author(3, "Jack Kerouac", "On The Road", "USA");

        ArrayList<Author> authors = new ArrayList<>();
        authors.add(w1);
        authors.add(w2);
        authors.add(w3);

        for(int i = 0 ; i < authors.size() ; i++){
            System.out.println(authors.get(i));
            }
        
        Scanner scan = new Scanner(System.in);
        System.out.print("Enter the author's ID: ");

        int num = scan.nextInt();
        
        GetAuthor theAuthor = new GetAuthor();
        Author author = theAuthor.returnAuthor(num,authors);
        
        System.out.println(author);  
    }
}