Account.java

package org.prevayler.demos.demo2.business;
import java.util.*;

public class Account implements java.io.Serializable {
  private static final long serialVersionUID=3998522662411373397L;
  private long number;
  private String holder;
  private long balance=0;
  private List transactionHistory=new ArrayList();
  private transient Set listeners;
  private Account(){
  }
  Account(  long number,  String holder) throws InvalidHolder {
    this.number=number;
    holder(holder);
  }
  public long number(){
    return number;
  }
  public String toString(){
    return numberString() + " - " + holder;
  }
  public String numberString(){
    return numberString(number);
  }
  static String numberString(  long number){
    return (new java.text.DecimalFormat("00000").format(number));
  }
  public String holder(){
    return holder;
  }
  public void holder(  String holder) throws InvalidHolder {
    verify(holder);
    this.holder=holder;
    notifyListeners();
  }
  public long balance(){
    return balance;
  }
  public void deposit(  long amount,  Date timestamp) throws InvalidAmount {
    verify(amount);
    register(amount,timestamp);
  }
  public void withdraw(  long amount,  Date timestamp) throws InvalidAmount {
    verify(amount);
    register(-amount,timestamp);
  }
  private void register(  long amount,  Date timestamp){
    balance+=amount;
    transactionHistory.add(new AccountEntry(amount,timestamp));
    notifyListeners();
  }
  private void verify(  long amount) throws InvalidAmount {
    if (amount <= 0)     throw new InvalidAmount("Amount must be greater than zero.");
    if (amount > 10000)     throw new InvalidAmount("Amount maximum (10000) exceeded.");
  }
  public List transactionHistory(){
    return transactionHistory;
  }
  public void addAccountListener(  AccountListener listener){
    listeners().add(listener);
  }
  public void removeAccountListener(  AccountListener listener){
    listeners().remove(listener);
  }
  private Set listeners(){
    if (listeners == null)     listeners=new HashSet();
    return listeners;
  }
  private void notifyListeners(){
    Iterator it=listeners().iterator();
    while (it.hasNext()) {
      ((AccountListener)it.next()).accountChanged();
    }
  }
public class InvalidAmount extends Exception {
    private static final long serialVersionUID=3343517565045905857L;
    InvalidAmount(    String message){
      super(message);
    }
  }
  private void verify(  String holder) throws InvalidHolder {
    if (holder == null || holder.equals(""))     throw new InvalidHolder();
  }
public class InvalidHolder extends Exception {
    private static final long serialVersionUID=-3234126892127577122L;
    InvalidHolder(){
      super("Invalid holder name.");
    }
  }
}