Frustrating- logic error, but where?

[Sal Velinus]

Ok, I eliminated the constructor problem (still don't know why it occurred), but now a new problem.
This is supposed to be a checking account with a savings account as overdraft protection. That part seems ok, except the overdraft method (trfFunds()) doesn't seem to work, and I can't see why. The program subtracts any amount from checking, putting it into negative values, when it should instead withdraw from savings, deposit in checking, then withdraw from savings. It should throw an NSF exception if there's not enough in savings.
Instead, it leaves savings alone and deducts any amount from checking (both are initialized to $500).
I've been over and over this and can't find the error. It compiles and runs ok, just doesn't work correctly. Relevant code below. Thanks for any help!
Test driver code:

public static void main(String[] args)
    {
Customer rudeBoy = Customer.example1();
System.out.println(rudeBoy);
        try
        {
            System.out.println("Legal withdrawal from checking");
    rudeBoy.getAcct(0).withdraw(300);
    System.out.println(rudeBoy);
    
            System.out.println("Legal withdrawal from checking using savings");
    rudeBoy.getAcct(0).withdraw(400);
    System.out.println(rudeBoy);
    
    System.out.println("Illegal withdrawal from checking");
    rudeBoy.getAcct(0).withdraw(300);
    System.out.println(rudeBoy);
        }
        catch(NSFException e)
        {
            System.out.println("XInsufficient funds in: " + e.getAcctNum());
            System.out.println("\tBalance is: " + e.getBalance() + "\n");
        }

Checking code:

public void withdraw(double amt) //throws NSFException
{
        if ( amt <= getBalance())
        {
            setBalance(getBalance() - amt);
        }
        else
        {
            if (trfFunds(amt, this))
            {
                setBalance(getBalance() - amt);
            }
/**            else
            {
                throw new NSFException("NSF funds in overdraft account", getTrfAcct(), getBalance());
            } */
        }
    }

DemandAccount code (base class to Checking) that hold trfFunds()):

public boolean trfFunds(double amtShort, DemandAccount requestor)
{
        boolean trf = false;
        if (amtShort <= requestor.getTrfAcct.getBalance())
        {
            trf = true;
            try
            {
                requestor.getTrfAcct.withdraw(amtShort);
            }
            catch(NSFException e)
            {
                System.out.println("Demand Account Exception: Insufficient funds in: " + e.getAcctNum());
                System.out.println("\tBalance is: " + e.getBalance() + "\n");
            }
            requestor.deposit(amtShort);
        }
        return trf;
    }

Thanks!
[ April 23, 2002: Message edited by: Greg Adams ]

[Dirk Schreckmann]

One problem (or so I think):
It looks like that if the withdraw(double) method discovers that the account funds are inadequate, it invokes trfFunds(double, DemandAccount), which invokes withdraw(double), which invokes trfFunds(double, DemandAccount), which invokes withdraw(double), which invokes trfFunds(double, DemandAccount), which invokes withdraw(double), etc.
Or did I miss something?
[ April 23, 2002: Message edited by: Dirk Schreckmann ]

[Sal Velinus]

Checking and savings are both subclasses of abstract class DemandAccount, which is a subclass of Abstract class Account.
Checking has it's own withdraw() method, which calls trfFunds() in DemandAccount. Savings uses the withdraw method in DemandAccount. requestor is the Checking account instance, while trfAcct is the Savings instance designated as the overdraft.
So, I don't think it's an endless loop. Checking's withdraw() calls trfFunds(), which then calls Savings withdraw(). At least it's supposed to. If Savings balance is too low, an exception is thrown. At least it's supposed to.

[Dirk Schreckmann]

OK. I have a feeling that my powers of guessing will only get bounced around a bit here with things like: "Nope. I didn't tell you about this." or "Nope. I didn't tell you about that."
So, in the sake of maximizing my powers, could you please post everything relevant in its simplest form with very clear identifiers (please not too many acronyms - I can hand a couple).
Good Luck.
[ April 24, 2002: Message edited by: Dirk Schreckmann ]

[Sal Velinus]

Well, ok, but it's several files worth. I didn't want to clutter the board.
DemandAccount

package banking;
public abstract class DemandAccount extends Account
{
    public DemandAccount()
    {}
    public DemandAccount(double newBal)
    {
        super(newBal);
    }
    public void deposit(double amt) 
    {
        setBalance(getBalance() + amt);
    }
    public void withdraw(double amt) throws NSFException
    {
        if (amt <= getBalance())
        {
           setBalance(getBalance() - amt);
        }
        else
        {
          throw new NSFException("\nDemandAccount Exception", getAcctNum(), getBalance());
        }
    }
    public boolean trfFunds(double amtShort, DemandAccount requestor)
    {
        boolean trf = false;
        if (amtShort <= requestor.getTrfAcct.getBalance())
        {
            trf = true;
            try
            {
                requestor.getTrfAcct.withdraw(amtShort);
            }
            catch(NSFException e)
            {
                System.out.println("Demand Account Exception: Insufficient funds in: " + e.getAcctNum());
                System.out.println("\tBalance is: " + e.getBalance() + "\n");
            }
            requestor.deposit(amtShort);
        }
        return trf;
    }
}

Checking

package banking;
public class Checking extends DemandAccount
{  
    private DemandAccount trfAcct;
                
    public Checking()
    {this(0.0);}
    public Checking(double newBal)
    {
        super(newBal);
        setAcctNum("CHK" + createNextAcctNum());
    }
        public Checking(double newBal, DemandAccount odAcct)
    {
        this(newBal);
        setTrfAcct(odAcct);
    }
        public DemandAccount getTrfAcct()
    {
        return trfAcct;
    }
        
    public void setTrfAcct(DemandAccount otherAcct)
    {
        trfAcct = otherAcct;
    }
        public void withdraw(double amt) //throws NSFException
    {
        if ( amt <= getBalance())
        {
            setBalance(getBalance() - amt);
        }
        else
        {
            if (trfFunds(amt, this))
            {
                setBalance(getBalance() - amt);
            }
/**            else
            {
                throw new NSFException("NSF funds in overdraft account", getTrfAcct(), getBalance());
            } */
        }
    }
        public String toString()
    {   
        return (super.toString() + "\n\tTransfer Account Info: \n" + getTrfAcct() +  '\n');
    }

    public static DemandAccount example1()
    {
        return( new Checking(500.0, Savings.example1()));
    }   
}

Savings

package banking;
public class Savings extends DemandAccount
{
    
        private static double interestRate;
        public Savings()
    {this(0.0);}
        public Savings(double newBal)
    {
        super(newBal);
        setAcctNum("SAV" + createNextAcctNum());
    }        
    
        public static double getInterestRate()
    {
        return interestRate;
    }
    
    public static void setInterestRate(double newRate)
    {
        interestRate = newRate;
    }
        
    
    public String toString()
    {
        return (super.toString() +  "\n\tInterest Rate: " + (getInterestRate() * 100) + "%\n\n");
    }
    
    public static DemandAccount example1()
    {
        return( new Savings(500.0));
    }   
}

TestBanking (the driver class to test the classes)

package testScripts;
import banking.*;
import accountOwners.*;
public class TestBanking
{
    
    public static void main(String[] args)
    {
        Customer rudeBoy = Customer.example1();
        System.out.println(rudeBoy);
        try
        {
            System.out.println("Legal withdrawal from checking");
            rudeBoy.getAcct(0).withdraw(300);
            System.out.println(rudeBoy);
    
            System.out.println("Legal withdrawal from checking using savings");
            rudeBoy.getAcct(0).withdraw(400);
            System.out.println(rudeBoy);
            
            System.out.println("Illegal withdrawal from checking");
            rudeBoy.getAcct(0).withdraw(300);
            System.out.println(rudeBoy);
        }
        catch(NSFException e)
        {
            System.out.println("XInsufficient funds in: " + e.getAcctNum());
            System.out.println("\tBalance is: " + e.getBalance() + "\n");
        }
    }
}

and finally Customer

package accountOwners;
import banking.*;
import java.util.*;
public class Customer
{
    private String name;
    private Account[] accts;
    
    public Customer()
    {
        this("Anonymous");
    }
        public Customer(String newName)
    {
        setName(newName);
        Account[] x = new Account[3];
        setAccts(accts);
    } 
    
    
    public Account[] getAccts()
    {
        return accts;
    }
    
    public Account getAcct(int i)
    {
        return accts[i];
    }
    public String getName()
    {
        return name;
    }
    public void setAccts(Account[] allAccts)
    {
        accts = allAccts;
    }
    public void setName(String newName)
    {
        name = newName;
    }
    
    public void addAnAccount(Account x, int index)
    {
        if (accts.length >= index)
        {
            accts[index] = x;
        }
        else
        {
            Account[] newAccts = new Account[index + 1];
            System.arraycopy(accts, 0, newAccts, 0, accts.length);
            newAccts[index] = x;
            accts = newAccts;
        }
    }
    public String toString()
    {
        String x = "";
        System.out.println("\nCustomer: " + getName() + " Accounts:\n");
        for (int i = 0; i < accts.length; i++)
        {
            if (accts[i] != null)
            {
                x = x + "Index [" + i + "]\n" +  accts[i].toString();
            }
        }
        return x;       
    }
    public static Customer example1()
    {
        Customer bob = new Customer("Bob");
        bob.addAnAccount(Checking.example1(), 0);
//      bob.accts[0] = Savings.example1();
//      bob.accts[1] = Checking.example1();
        
        return bob;
    }
}

Hope that's better, I appreciate the help.
[ April 24, 2002: Message edited by: Dirk Schreckmann ]