public class MailSystem
1: import java.util.ArrayList;
3: /**
4: A system of voice mail boxes.
5: */
6: public class MailSystem
7: {
8: /**
9: Constructs a mail system with a given number of mailboxes
10: @param mailboxCount the number of mailboxes
11: */
12: public MailSystem(int mailboxCount)
13: {
14: mailboxes = new ArrayList<Mailbox>();
16: // Initialize mail boxes.
18: for (int i = 0; i < mailboxCount; i++)
19: {
20: String passcode = "" + (i + 1);
21: String greeting = "You have reached mailbox " + (i + 1)
22: + ". \nPlease leave a message now.";
23: mailboxes.add(new Mailbox(passcode, greeting));
24: }
25: }
27: /**
28: Locate a mailbox.
29: @param ext the extension number
30: @return the mailbox or null if not found
31: */
32: public Mailbox findMailbox(String ext)
33: {
34: int i = Integer.parseInt(ext);
35: if (1 <= i && i <= mailboxes.size())
36: return mailboxes.get(i - 1);
37: else return null;
38: }
40: private ArrayList<Mailbox> mailboxes;
41: }