Book

public class Book {
String name;
String writer;
int year;
double price;
public Book(String name, String writer, int year, double price) {
    super();
    this.name = name;
    this.writer = writer;
    this.year = year;
    this.price = price;
}
public String getName() {
    return name;
}
public void setName(String name) {
    this.name = name;
}
public String getWriter() {
    return writer;
}
public void setWriter(String writer) {
    this.writer = writer;
}
public int getYear() {
    return year;
}
public void setYear(int year) {
    this.year = year;
}
public double getPrice() {
    return price;
}
public void setPrice(double price) {
    this.price = price;
}

public boolean newBook(int year) {
    if(year - this.year <= 3)
        return true;
    else
        return false;
}

public double newPrice(double percent) {
    return (double) (this.price += this.price*percent/100);
}
}