// Fig. 14.18: CreateSequentialFile.java
// Writing objects sequentially to a file with class ObjectOutputStream.
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.util.NoSuchElementException;
import java.util.Scanner;

import com.deitel.jhtp6.ch14.AccountRecordSerializable;

public class CreateSequentialFile
{
   private ObjectOutputStream output; // outputs data to file

   // allow user to specify file name
   public void openFile()
   {
      try // open file
      {
         output = new ObjectOutputStream(
            new FileOutputStream( "clients.ser" ) );
      } // end try
      catch ( IOException ioException )
      {
         System.err.println( "Error opening file." );
      } // end catch
   } // end method openFile

   // add records to file
   public void addRecords()
   {
      AccountRecordSerializable record; // object to be written to file
      int accountNumber = 0; // account number for record object
      String firstName; // first name for record object
      String lastName; // last name for record object
      double balance; // balance for record object

      Scanner input = new Scanner( System.in );

      System.out.printf( "%s\n%s\n%s\n%s\n\n",
         "To terminate input, type the end-of-file indicator ",
         "when you are prompted to enter input.",
         "On UNIX/Linux/Mac OS X type <ctrl> d then press Enter",
         "On Windows type <ctrl> z then press Enter" );

      System.out.printf( "%s\n%s", 
         "Enter account number (> 0), first name, last name and balance.",
         "? " );

      while ( input.hasNext() ) // loop until end-of-file indicator
      {
         try // output values to file
         {
            accountNumber = input.nextInt(); // read account number
            firstName = input.next(); // read first name
            lastName = input.next(); // read last name
            balance = input.nextDouble(); // read balance

            if ( accountNumber > 0 )
            {
               // create new record
               record = new AccountRecordSerializable( accountNumber,
                  firstName, lastName, balance );
               output.writeObject( record ); // output record
            } // end if
            else
            {
               System.out.println(
                  "Account number must be greater than 0." );
            } // end else
         } // end try
         catch ( IOException ioException )
         {
            System.err.println( "Error writing to file." );
            return;
         } // end catch
         catch ( NoSuchElementException elementException )
         {
            System.err.println( "Invalid input. Please try again." );
            input.nextLine(); // discard input so user can try again
         } // end catch

         System.out.printf( "%s %s\n%s", "Enter account number (>0),",
            "first name, last name and balance.", "? " );
      } // end while
   } // end method addRecords

   // close file and terminate application 
   public void closeFile() 
   {
      try // close file
      {
         if ( output != null )
            output.close();
      } // end try
      catch ( IOException ioException )
      {
         System.err.println( "Error closing file." );
         System.exit( 1 );
      } // end catch
   } // end method closeFile
} // end class CreateSequentialFile

/*************************************************************************
* (C) Copyright 1992-2005 by Deitel & Associates, Inc. and               *
* Pearson Education, Inc. All Rights Reserved.                           *
*                                                                        *
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