BCA JAVA 2015 SLIP 13

import java.util.*;

import java.io.*;

class Slip13

{

      public static void main(String a[]) throws Exception

      {

            BufferedReader br=new BufferedReader(new InputStreamReader(System.in));

            System.out.println("enter file name to copy");

            String f1=br.readLine();

           

            System.out.println("enter destination file");  

            String f2=br.readLine();

           

            FileReader fr=new FileReader(f1);

            FileWriter fw=new FileWriter(f2);

            int ch;

            while((ch=fr.read() ) != -1)

            {

                  char ch1=(char)ch;

                  if(Character.isUpperCase(ch1))

                  {

                        ch1=Character.toLowerCase(ch1);

                        fw.write(ch1);

                  }

                  else if(Character.isLowerCase(ch1))

                  {

                        ch1=Character.toUpperCase(ch1);    

                        fw.write(ch1);

                  }

                  else if(Character.isDigit(ch1))

                  {

                        ch1='*';

                        fw.write(ch1);

                  }

                  else if(Character.isSpace(ch1))

                  {

                        fw.write(ch1);

                  }

            }

            fr.close();

            fw.close();

      }

}