001package horstmann.ch02_mail; 002import java.util.ArrayList; 003 004/** 005 A system of voice mail boxes. 006 */ 007public class MailSystem 008{ 009 /** 010 Constructs a mail system with a given number of mailboxes 011 @param mailboxCount the number of mailboxes 012 */ 013 public MailSystem(int mailboxCount) 014 { 015 mailboxes = new ArrayList<Mailbox>(); 016 017 // Initialize mail boxes. 018 019 for (int i = 0; i < mailboxCount; i++) 020 { 021 String passcode = "" + (i + 1); 022 String greeting = "You have reached mailbox " + (i + 1) 023 + ". \nPlease leave a message now."; 024 mailboxes.add(new Mailbox(passcode, greeting)); 025 } 026 } 027 028 /** 029 Locate a mailbox. 030 @param ext the extension number 031 @return the mailbox or null if not found 032 */ 033 public Mailbox findMailbox(String ext) 034 { 035 int i = Integer.parseInt(ext); 036 if (1 <= i && i <= mailboxes.size()) 037 return mailboxes.get(i - 1); 038 else return null; 039 } 040 041 private ArrayList<Mailbox> mailboxes; 042}