【重构】【重构：第一个案例】

// 简单的纯数据类
public class Movie {
    public static final int CHILDREN = 2;
    public static final int REGULAR = 0;
    public static final int NEW_RELEASE = 1;

    private String _title;
    private int _priceCode;

    public Movie(String title, int priceCode) {
        _title = title;
        _priceCode = priceCode;
    }

    public String getTitle() {
        return _title;
    }

    public int getPriceCode() {
        return _priceCode;
    }

    public void set_title(String _title) {
        this._title = _title;
    }
}

// 表明某个顾客租了一部影片
public class Rental {
    private Movie _movie;
    private int _daysRent;

    public Rental(Movie movie, int daysRent) {
        _movie = movie;
        _daysRent =daysRent;
    }

    public Movie getMovie() {
        return _movie;
    }

    public int getDaysRent() {
        return _daysRent;
    }
}

import java.util.Vector;

public class Customer {
    private String _name;
    private Vector _rentals = new Vector();

    public Customer(String name) {
        _name = name;
    }

    public void addRental(Rental arg) {
        _rentals.addElement(arg);
    }

    public String getName() {
        return _name;
    }
}