This program prints the last k lines from a given file.

PrintLastKLines.java

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.util.Scanner;

/**
 * Created with IntelliJ IDEA.
 * User: Ravi
 * Date: 10/14/13
 * Time: 6:36 AM
 * To change this template use File | Settings | File Templates.
 */
public class PrintLastKLines {
    public static void main(String[] args)
    {
        try {
            Scanner reader = new Scanner(System.in);
            String strFilePath = reader.nextLine();
            Scanner fileReader = new Scanner(new FileReader(strFilePath));
            int kLines = Integer.parseInt(reader.nextLine());
            String[] strArrayLines = new String[kLines];
            int nLines = 0; //Total number of lines in the file
            int ind = 0;  //running index
            if( kLines > 0)
            {
                while( fileReader.hasNext() )
                {
                    strArrayLines[ind] = fileReader.nextLine();
                    ind = (ind + 1)%kLines;
                    nLines++;
                }
            }
            int i;
            //If the file contains less number of lines than kLines
            if( nLines < kLines )
            {
                //print from the beginning of the array
                for( i = 0; i < nLines; i++)
                {
                    System.out.println( strArrayLines[i] );
                }
            }
            else
            {
                for( i = 0; i < kLines; i++ )
                {
                    System.out.println( strArrayLines[ind] );
                    ind = (ind+1) % kLines;
                }
            }
        }
        catch (FileNotFoundException fnfe)
        {
            System.out.println( fnfe.getMessage() );
        }
        catch(NumberFormatException nfe)
        {
            System.out.println( nfe.getMessage() );
        }
    }
}