/*
  Author  : Michael Robinson
  Program : filesLargeSize.java
  Purpose : This program uses the Formatter class 
            this is a very quick way
            to create the file called fileone then we
            write data into into and finally
            close it.
            ************** WARNING ******************
            this program will produce a text file
            of size close to three gigabytes 
                         
  Updated : Jan 29, 2099
*/


import java.util.*;
import java.io.*;
import java.text.DecimalFormat;


public class filesLargeSize 
{
    //create the public global object recordsFormat of class DecimalFormat
    public static DecimalFormat recordsFormat = new DecimalFormat( " #,###" );
            

    public static void writeFile()
    {
        System.out.println( "\n  Writting records into the text LargeFile"  );
        
        try
        {
            //creates the bufferedWrite object of BufferedWriter class to write data
            //into the LargeFile text file. This class allows us to write very large
            //files limited by the storage available  
            BufferedWriter bufferedWrite = new BufferedWriter( new FileWriter( "LargeFile") );

            String record = "Java uses the File class in java.io.File";
 
            int x = 0; 
            while( x < 69999999 ) 
            {
                bufferedWrite.write( record + "\n" ); //write record to file
                x++;
            }
            bufferedWrite.close();
            
            System.out.println( "\n  Records written = " + recordsFormat.format(x) ); 
            
        }
        catch( Exception e )
        {
            e.printStackTrace();
        }

    }//end public static void writeFile()


    public static void readFile()
    {
        System.out.println( "\n  Reading records from the text LargeFile"  );
            
        try
        {
            //creates the bufferedReader object of BufferedReader class to read data from the
            //LargeFile text file. This class allows us to read from very large files
            BufferedReader bufferedReader = new BufferedReader( new FileReader( "LargeFile") );
            
            String record = bufferedReader.readLine(); //read record from file
            
            int x = 1; 
            while( record != null )
            {
                record = bufferedReader.readLine(); //read record from file
                x++;
            }
            bufferedReader.close();
            
            System.out.println( "  Records read = " + recordsFormat.format(x-1)  + "\n\n");
            
        }
        catch( Exception e )
        {
            e.printStackTrace();
        }

    }//end public static void readFile()
    
    
    public static void main( String args[] ) 
    {
        Scanner kb = new Scanner( System.in );
           
        System.out.println( "\n\n\n************** WARNING ******************" );
        System.out.println( "  this program will produce a text file" );
        System.out.println( "    of size close to three gigabytes" );
        System.out.print( "\n      Do you want to continue (Y/N): " );
 
        //read the keyboard and assign value entered to the keyboard String variable
        String keyboard = kb.nextLine(); 
           
        //extract the first character of the keyboard String and assign it to the String letter   
        String letter = keyboard.substring(0,1).toUpperCase();

        //displays the distance from Y's ASCII code. 0 means that the letter entered was Y   
        System.out.println( "\n      ASCII distance from Y to " + letter + " = " + letter.compareTo( "Y" )  ); 
           
        if( letter.compareTo( "Y" ) != 0 ) 
        {   
            System.out.print( "\n   I received " + letter + " Exiting program, Thank You\n\n\n" );
            System.exit(0); //exit/terminate this program at this point
        }
        
        writeFile();  //call this method
        readFile();   //call this method

    }//end public static void main( String args[] ) 

}//end public class filesLargeSize