重构之一起点

以你之姓@ 2022-08-11 00:40 117阅读 0赞

这是一个影片出租店用的程序，计算每一位顾客的消费金额打印详单。操作者告诉程序：顾客租了那些影片，租期多长，程序会根据租赁时间和影片类型算出费用。影片分为三类：普通片，儿童片和新片。除了计算费用，还要为常客计算积分，积分会根据租片种类是否为新片而有所不同。

package movie;
    
    import java.util.Enumeration;
    import java.util.Vector;
    
    public class Customer {
    	private String _name;
    	private Vector _rentals = new Vector();
    
    	public Customer(String name) {
    		this._name = name;
    	}
    
    	public void addRental(Rental rental) {
    		this._rentals.add(rental);
    	}
    
    	public String getName() {
    		return this._name;
    	}
    
    	public String statement() {
    		double totalAmount = 0;
    		int frequentRenterPoints = 0;
    		Enumeration rentals = this._rentals.elements();
    		String result = "Rental Record for " + getName() + "\n";
    		while (rentals.hasMoreElements()) {
    			double thisAmount = 0;
    			Rental each = (Rental) rentals.nextElement();
    			// ....
    //			switch (each.get_movie().get_priceCode()) {
    //			case Movie.REGULAR:
    //				thisAmount += 2;
    //				if (each.get_daysRented() > 2)
    //					thisAmount += (each.get_daysRented() - 2) * 1.5;
    //
    //				break;
    //			case Movie.NEW_RELEASE:
    //				thisAmount += 3;
    //				break;
    //			case Movie.CHILDRENS:
    //				thisAmount += 1.5;
    //				if (each.get_daysRented() > 3)
    //					thisAmount += (each.get_daysRented() - 3) * 1.5;
    //				break;
    //			default:
    //				break;
    //			}
    			thisAmount = amountFor(each);
    			frequentRenterPoints ++;
    			if((each.get_movie().get_priceCode() == Movie.NEW_RELEASE) && each.get_daysRented() > 1)
    				frequentRenterPoints ++;
    			result += "\t" + each.get_movie().get_title() + "\t" + String.valueOf(thisAmount) + "\n";
    		}
    		
    		return result;
    	}
    	
    	private double amountFor(Rental aRental){
    		int thisAmount = 0;
    		switch (aRental.get_movie().get_priceCode()) {
    		case Movie.REGULAR:
    			thisAmount += 2;
    			if (aRental.get_daysRented() > 2)
    				thisAmount += (aRental.get_daysRented() - 2) * 1.5;
    
    			break;
    		case Movie.NEW_RELEASE:
    			thisAmount += 3;
    			break;
    		case Movie.CHILDRENS:
    			thisAmount += 1.5;
    			if (aRental.get_daysRented() > 3)
    				thisAmount += (aRental.get_daysRented() - 3) * 1.5;
    			break;
    		default:
    			break;
    		}
    		return thisAmount;
    	}
    
    }

package movie;
    
    public class Movie {
    	public static final int CHILDRENS = 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) {
    		this._title = title;
    		this._priceCode = priceCode;
    	}
    
    	public String get_title() {
    		return _title;
    	}
    
    	public void set_title(String _title) {
    		this._title = _title;
    	}
    
    	public int get_priceCode() {
    		return _priceCode;
    	}
    
    	public void set_priceCode(int _priceCode) {
    		this._priceCode = _priceCode;
    	}
    
    }

package movie;
    
    public class Rental {
    	private Movie _movie;
    	private int _daysRented;
    	
    	public Rental(Movie movie, int daysRented) {
    		this._movie = movie;
    		this._daysRented = daysRented;
    	}
    
    	public Movie get_movie() {
    		return _movie;
    	}
    
    	public void set_movie(Movie _movie) {
    		this._movie = _movie;
    	}
    
    	public int get_daysRented() {
    		return _daysRented;
    	}
    
    	public void set_daysRented(int _daysRented) {
    		this._daysRented = _daysRented;
    	}
    	
    	
    }