Master of Science thesis Fighting Spam

System.out.println("withdrawFromUpFront 20.0 from Bents account");
System.out.println(accounts.toString());
/*
try
{
PASTE IN THE CES !!!!!!!!!!!!!!!!!!!!!!!!!!!!
acc.withdrawFromUpFront(amount);
}
catch(Exception ex)
{
String error = "The client could pay for the coins. Terminating! (..not
the client...just the connection). "+ex.getMessage();
Debugger.debug(getClass(), 1,error);
throw new Exception(error);
}
*/
}
catch(Exception ex)
{
}
}
}
10.4.5.b BankAccount
package SpamCash.Servers.CES;
import java.security.cert.Certificate;
import java.util.Vector;
public class BankAccount
{
public String username;
public String password;
public double balance;
public double paidUpFront;
public Certificate cert;
public Vector activationNumbers;
public BankAccount(String username, String password, double balance)
{
this.username = username;
this.password = password;
this.balance = balance;
activationNumbers = new Vector();
}
public void deposit(double amount) throws Exception
{
if(amount >= 0)
balance += amount;
else
throw new Exception("BankAccount: Cannot deposit a negative amount!
("+amount+")");
}
public void withdraw(double amt) throws Exception
{
if(amt