/**
 Demonstrates use of the class File with text files.
*/
import java.io.*;
import java.util.*;

public class FileClassDemo
{
    public static void main(String[] args)
    {
        String name = null;
        System.out.println("I will show you the first line");
        System.out.println("in a text file you name.");
        System.out.println("The file must contain one or more lines.");
        System.out.println("Enter file name:");
        Scanner keyboard = new Scanner(System.in);

        name = keyboard.next( );
        File fileObject = new File(name);

        while (( ! fileObject.exists( ))
                          || ( ! fileObject.canRead( )))
        {
           if ( ! fileObject.exists( ))
              System.out.println("No such file");
           else // ! fileObject.canRead( )
              System.out.println("That file is not readable.");
           System.out.println("Enter file name again:");
           name = keyboard.next( );
           fileObject = new File(name);
        }

        try
        {
           BufferedReader fileInput =
                  new BufferedReader(new FileReader(name));
           System.out.println("The first line in the file is:");
           String firstLine = fileInput.readLine( );
           System.out.println(firstLine);
           fileInput.close( );
       }
       catch(IOException e)
       {
          System.out.println("Problem reading from file.");
       }
    }
}