package ora.ch6;import java.io.InputStream;import java.io.IOException;/** * A class that represents a book listing * at an online book set, including the number * of reviews for the book and its sales ranking. */public class BookInfo {    int    id;          // Used when persisting    String isbn;        // The book ISBN    String title;       // The book title    int    reviews;     // Number of reviews    int    ranking;     // Current ranking    int    lastReviews; // Last review count    int    lastRanking;  // Last ranking    public BookInfo(String isbn) {        this.isbn = isbn;    }    public String getIsbn() {        return isbn;    }    public String getTitle() {        return title;    }    public int getReviews() {        return reviews;    }    public int getRanking() {        return ranking;    }    public int getLastReviews() {        return lastReviews;    }    public int getLastRanking() {        return lastRanking;    }    // Installs details parsed from an input stream    public void setFromInputStream(InputStream is) {        // Use an InputHelper to search the input        InputHelper helper = new InputHelper(is);        try {            // Default new values to current values            int newRanking = this.ranking;            int newReviews = this.reviews;            boolean found = helper.moveAfterString("buying info: ");            if (!found) {                return;            }            // Gather the title from the rest of this line            StringBuffer titleBuffer = helper.getRestOfLine();            // Look for the number of reviews            found = helper.moveAfterString("Based on ");            if (!found) {                return;            }            // Gather the number of reviews from the current location            String reviewString = helper.gatherNumber();            // Look for the sales rank            found = helper.moveAfterString("Sales Rank: ");            if (!found) {                return;            }            // Gather the number from the current location            String rankingString = helper.gatherNumber();            // Having safely found everything, set the new title            title = titleBuffer.toString().trim();            // Now convert the reviews and ranking to integers.            // If they fail to convert, just leave the existing            // values.            try {                newRanking = Integer.parseInt(rankingString);            } catch (NumberFormatException ex) {            }            if (newRanking != ranking) {                lastRanking = ranking;                ranking = newRanking;                if (lastRanking == 0) {                    // First time, set last and current                    // to the same value                    lastRanking = ranking;                }            }            try {                newReviews = Integer.parseInt(reviewString);            } catch (NumberFormatException ex) {            }            if (newReviews != reviews) {                lastReviews = reviews;                reviews = newReviews;                if (lastReviews == 0) {                    // First time, set last and current                    // to the same value                    lastReviews = reviews;                }            }        } catch (IOException ex) {        } finally {            // Allow garbage collection            helper.dispose();            helper = null;        }    }}