This is not coming easy to me. HELP!

/* Accounting class

Anderson, Franceschi

*/

import javax.swing.JOptionPane;

import java.text.DecimalFormat;

import javax.swing.JFrame;

import java.awt.Graphics;

import java.util.ArrayList;

import java.io.FileInputStream;

import java.io.ObjectInputStream;

import java.io.FileOutputStream;

import java.io.ObjectOutputStream;

import java.io.IOException;

import java.io.EOFException;

import java.io.FileNotFoundException;

public class Accounting extends JFrame

{

private BankAccount bankAccount;

public Accounting( )

{

super( "Reading objects from a file" );

bankAccount = new BankAccount( getBackground( ) );

setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );

setSize( 300, 300 );

setVisible( true );

}

public void balanceCheckBook( )

{

//

// ***** Student writes the body of this method *****

//

// Using a while loop, read the file transactions.obj

// The file transactions.obj contains transaction objects

//

//You will need to call the animate method inside

//the body of the loop that reads the objects

//

// The animate method takes two arguments:

//a Transaction object, representing the transaction

//a double, representing the new checkbook balance

//So if these two variables are transaction and balance,

// then the call to animate will be:

//

//animate( transaction, balance );

//

//You should make that call in the body of your while

//loop, after you have updated the checkbook balance

//

//

//end of student code

//

}

public void writeTransactions( ArrayList transactionList )

{

//

// writing to file transactions.obj

//

try

{

FileOutputStream fos = new FileOutputStream( "transactions.obj" );

ObjectOutputStream oos = new ObjectOutputStream( fos );

Transaction tempTransaction;

for ( int i = 0; i < transactionList.size( ) ; i++ )

{

tempTransaction = ( Transaction ) transactionList.get( i );

oos.writeObject( tempTransaction );

}

oos.close( );

}

catch ( IOException ioe )

{

System.out.println( ioe.toString( ) );

System.out.println( ioe.getMessage( ) );

}

}

public void animate( Transaction currentTransaction, double currentBalance )

{

// set the currentTransaction data member in the bankAccount object

bankAccount.setCurrentTransaction( currentTransaction );

// set the currentBalance data member in the bankAccount object

bankAccount.updateBalance( currentBalance );

repaint( );

try

{

Thread.sleep( 3000 ); // wait for the animation to finish

}

catch ( Exception e )

{

}

}

public void paint( Graphics g )

{

super.paint( g );

if ( bankAccount != null )

bankAccount.draw( g );

}

public static void main( String [] args )

{

Accounting app = new Accounting( );

// Generate an ArrayList of Transaction objects to write to file Transaction.obj

ArrayList transactionList = new ArrayList( );

Check c1 = new Check( -500.00 );

transactionList.add( c1 );

Deposit d1 = new Deposit( 3000.00 );

transactionList.add( d1 );

Withdrawal w1 = new Withdrawal( -400.00 );

transactionList.add( w1 );

c1 = new Check( -300.00 );

transactionList.add( c1 );

// write transactions as objects to file transaction.obj

app.writeTransactions( transactionList );

// read transaction.obj, balance the checkbook

app.balanceCheckBook( );

}

}