import java.io.Console;

import java.util.Arrays;

import java.io.IOException;

public class UseConsole

{

  static char [] oldPass;

  public static void main (String args[]) throws IOException

   {

    Console c = System.console();

    if (c == null)

    {

     System.err.println("Console Object is not available.");

     System.exit(1);

    }

   String login = c.readLine("Enter your login Name: ");

   oldPass = c.readPassword("Enter your Existing password: ");

   if (check(login, oldPass))

    {

     boolean flag;

     do

{  

char [] newPass1 = c.readPassword("Enter your new password: ");  

char [] newPass2 = c.readPassword("Enter new password again: ");  

flag = !Arrays.equals(newPass1, newPass2);

if (flag)

{

c.format("Mismatch the Passwords. Please try again.%n");

}    

else

{

change(newPass1);

c.format("Password for %s has changed.%n", login);

}

Arrays.fill(newPass1, ' ');

Arrays.fill(newPass2, ' ');

} while (flag);

}

}

//check method.

static boolean check(String login, char[] password) {

return true;

}

//change method.

static void change(char[] password) {

oldPass=password;

}

}