Book

package library;

import java.sql.Date;

public class Book implements Comparable<Book> {

    String title;
    String author;
    Date date;
    String ISBN;
    String format;
    String publisher;
    float price;
    String[] keywords;
    String[] inputArray;
    String input;

    public Book(String title_param, String author_param, java.util.Date date_param, String ISBN_param,
            String format_param, String publisher_param, float price_param, String keywords_param) {

        title = title_param;
        author = author_param;
        date = (Date) date_param;
        ISBN = ISBN_param;
        format = format_param;
        publisher = publisher_param;
        price = price_param;
        keywords = keywords_param.split(",");

    }

    public void setUserInput(String userIn) {
        input = userIn;
    }

    private int getRelevance(String userInput) {
        inputArray = userInput.split(",");
        int num = 0;

        for (int i = 0; i != keywords.length; i++) {
            String in = inputArray[i];

            for (int l = 0; l != keywords.length; l++) {
                if (in.equals(keywords[l]))
                    num++;
            }
        }

        return num;
    }

    public int compareTo(Book o) {
        if (this.getRelevance(input) > o.getRelevance(input)) {
            return 1;
        } else if (this.getRelevance(input) < o.getRelevance(input)) {
            return -1;
        }

        return 0;
    }
}