1 import java.util.*;
2
3 public class Customer {
4 private String _name;
5 private ArrayList _rentals = new ArrayList();
6
7 public Customer(String name) {
8 _name = name;
9 }
10
11 public void addRental(Rental arg) {
12 _rentals.add(arg);
13 }
14
15 public String getName() {
16 return _name;
17 }
18
19 // How many times do we traverse the rentals ArrayList?
20 // Does it matter?
21 public String statement()
22 {
23 StringBuffer buffer = new StringBuffer(_rentals.size() * 25);
24 buffer.append("Rental Record for " + getName() + "\n");
25 for(int i = 0, n = _rentals.size(); i < n; i++){
26 Rental rental = (Rental) _rentals.get(i);
27 //show figures for this rental
28 buffer.append("\t");
29 buffer.append(rental.getMovie().getTitle());
30 buffer.append("\t");
31 buffer.append(rental.getCharge());
32 buffer.append("\n");
33 }
34 //add footer lines
35 buffer.append("Amount owed is " + getTotalCharge() + "\n");
36
37 buffer.append("You earned " +
38 getTotalFrequentRenterPoints() +
39 " frequent renter points");
40 return buffer.toString();
41 }
42
43 private double getTotalCharge()
44 {
45 double result = 0;
46 for(int i = 0, n = _rentals.size(); i < n; i++)
47 result += ((Rental) _rentals.get(i)).getCharge();
48 return result;
49 }
50
51 private int getTotalFrequentRenterPoints()
52 {
53 int result = 0;
54 for(int i = 0, n = _rentals.size(); i < n; i++)
55 result += ((Rental)_rentals.get(i)).getFrequentRenterPoints();
56 return result;
57 }
58
59 private static long stressTest(Customer customer, Rental rental, int numberRentals)
60 {
61 for(int i = 0; i < numberRentals; i++)
62 customer.addRental(rental);
63 long startTime = System.currentTimeMillis();
64 double totalCharge = customer.getTotalCharge();
65 String statement = customer.statement();
66 return System.currentTimeMillis() - startTime;
67 }
68
69 public static void main(String argv[])
70 {
71 Customer harry = new Customer("Harry");
72 Movie movie = new Movie("Gone With The Wind", Movie.REGULAR);
73 Rental rental = new Rental(movie, 3);
74 harry.addRental(rental);
75 System.out.println(harry.statement());
76 Customer tom = new Customer("Tom");
77 // Suppose we have 1000000 rentals. How long will it take
78 // to compute the total chare?
79 int numberRentals = 1000000;
80 long timeToCompute = stressTest(tom, rental, 1000000);
81 System.out.println("time elapsed for " + numberRentals +
82 " rentals = " + timeToCompute);
83 }
84 }
85 // Output:
86 // $ java -classpath . Customer
87 // Rental Record for Harry
88 // Gone With The Wind 3.5
89 // Amount owed is 3.5
90 // You earned 1 frequent renter points
91 // time elapsed for 1000000 = 330, totalCharge is 3500000.0