// Fig. 17.4: CreateSequentialFile.java
// Demonstrating object output with class ObjectOutputStream.
// The objects are written sequentially to a file.
import java.io.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import com.deitel.jhtp3.ch17.BankUI;
import com.deitel.jhtp3.ch17.BankAccountRecord;

public class CreateSequentialFile extends JFrame {
   private ObjectOutputStream output;
   private BankUI userInterface;
   private JButton enter, open;

   public CreateSequentialFile()
   {
      super( "Creating a Sequential File of Objects" );

      getContentPane().setLayout( new BorderLayout() );
      userInterface = new BankUI();
      
      enter = userInterface.getDoTask();
      enter.setText( "Enter" );
      enter.setEnabled( false );  // disable button to start
      enter.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               addRecord();
            }
         }
      );

      addWindowListener(
         new WindowAdapter() {
            public void windowClosing( WindowEvent e )
            {
               if ( output != null ) {
                  addRecord();
                  closeFile();
               }
               else
                  System.exit( 0 );
            }
         }
      );
      open = userInterface.getDoTask2();

      open.setText( "Save As" );
      open.addActionListener(
         new ActionListener() {
            public void actionPerformed( ActionEvent e )
            {
               openFile();
            }
         }
      );
      getContentPane().add( userInterface, 
                            BorderLayout.CENTER );

      setSize( 300, 200 );
      show();
   }

   private void openFile()
   {
      JFileChooser fileChooser = new JFileChooser();
      fileChooser.setFileSelectionMode(
         JFileChooser.FILES_ONLY );
      
      int result = fileChooser.showSaveDialog( this );

      // user clicked Cancel button on dialog
      if ( result == JFileChooser.CANCEL_OPTION )
         return;

      File fileName = fileChooser.getSelectedFile();
      
      if ( fileName == null ||
           fileName.getName().equals( "" ) )
         JOptionPane.showMessageDialog( this, 
            "Invalid File Name",            
            "Invalid File Name",
            JOptionPane.ERROR_MESSAGE );
      else {
         // Open the file
         try {
            output = new ObjectOutputStream(
                        new FileOutputStream( fileName ) );
            open.setEnabled( false );
            enter.setEnabled( true );
         }
         catch ( IOException e ) {
            JOptionPane.showMessageDialog( this,
               "Error Opening File", "Error",
               JOptionPane.ERROR_MESSAGE );
         }      
      }
   }

   private void closeFile() 
   {
      try {
         output.close();
         System.exit( 0 );
      }
      catch( IOException ex ) {
         JOptionPane.showMessageDialog( this,
            "Error closing file",
            "Error", JOptionPane.ERROR_MESSAGE );
         System.exit( 1 );
      }
   }

   public void addRecord()
   {
      int accountNumber = 0;
      BankAccountRecord record;
      String fieldValues[] = userInterface.getFieldValues();
     
      // If the account field value is not empty
      if ( ! fieldValues[ 0 ].equals( "" ) ) {
         // output the values to the file
         try {
            accountNumber =
               Integer.parseInt( fieldValues[ 0 ] );

            if ( accountNumber > 0 ) {
               record = new BankAccountRecord(
                  accountNumber, fieldValues[ 1 ],
                  fieldValues[ 2 ],
                  Double.parseDouble( fieldValues[ 3 ] ) );
               output.writeObject( record );
               output.flush();
            }

            // clear the TextFields
            userInterface.clearFields();
         }
         catch ( NumberFormatException nfe ) {
            JOptionPane.showMessageDialog( this,
               "Bad account number or balance",
               "Invalid Number Format",
               JOptionPane.ERROR_MESSAGE );
         }
         catch ( IOException io ) {
            closeFile();
         }
      }
   }

   public static void main( String args[] )
   {
      new CreateSequentialFile();
   }
}

/**************************************************************************
 * (C) Copyright 1999 by Deitel & Associates, Inc. and Prentice Hall.     *
 * All Rights Reserved.                                                   *
 *                                                                        *
 * DISCLAIMER: The authors and publisher of this book have used their     *
 * best efforts in preparing the book. These efforts include the          *
 * development, research, and testing of the theories and programs        *
 * to determine their effectiveness. The authors and publisher make       *
 * no warranty of any kind, expressed or implied, with regard to these    *
 * programs or to the documentation contained in these books. The authors *
 * and publisher shall not be liable in any event for incidental or       *
 * consequential damages in connection with, or arising out of, the       *
 * furnishing, performance, or use of these programs.                     *
 *************************************************************************/