Create an interface “CreditCardInterface.

 

Create an interface “CreditCardInterface” with methods : viewCreditAmount(), useCard(), payCredit() and increaseLimit(). Create a class SilverCardCustomer (name, cardnumber (16 digits), creditAmount – initialized to 0, creditLimit - set to 50,000 ) which implements the above interface. Inherit class GoldCardCustomer from SilverCardCustomer having the same methods
but creditLimit of 1,00,000. Create an object of each class and perform operations. Display appropriate messages for success or failure of transactions. (Use method overriding)
i. useCard() method increases the creditAmount by a specific amount upto creditLimit ii. payCredit() reduces the creditAmount by a specific amount.
iii. increaseLimit() increases the creditLimit for GoldCardCustomers (only 3 times, not more than 5000Rs. each time)

credit.java 

import java.io.*;

interface CreditCard

{

void viewCreditAmount();

void increaseLimit()throws IOException;

void useCard()throws IOException ;

void payCard()throws IOException;

}

class SliverCardCustomer implements CreditCard

{

String name;

int card_no ;

double creditAmount;

double creaditLimit;

static int cnt;

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

SliverCardCustomer()

{

name="Noname" ;

card_no=0;

creditAmount=0;

creaditLimit=50000;

}

public void viewCreditAmount()

{

System.out.println("Your amount is : "+creditAmount) ;

}

public void getdata()throws IOException

{

System.out.println("Enter the name : ");

String name=(br.readLine());

System.out.println("Enter the card number :");

card_no=Integer.parseInt(br.readLine());

System.out.println("Enter Credit amount : ");

creditAmount=Double.parseDouble(br.readLine());

}

public void payCard()throws IOException

{

System.out.println("Enter amount to be pay");

double pay=Double.parseDouble(br.readLine()) ;

creditAmount=creditAmount-pay;

System.out.println("Balance is paid");

}

public void useCard()throws IOException

{

System.out.println("Enter amount : ");

double amount=Double.parseDouble(br.readLine());

if(amount<creditAmount)

{

creditAmount=creditAmount+amount;

viewCreditAmount();

System.out.println("Thanks for using the service") ;

}

else System.out.println("\nerror!");

}

public void increaseLimit()throws IOException

{

cnt++;

if(cnt<=3)

{

System.out.println("Enter amount limit to increse : ");

double amt=Double.parseDouble(br.readLine());

if(amt<=2500)

{

creaditLimit=creaditLimit+amt;

System.out.println("Amount limit to increse Successfully : ");

}

System.out.println("You can't increse creadit amount more than 2500 at a time ");

}

else

System.out.println("You can't increse limit more than 3 times ");

}

}

class GoldCardCustomer extends SliverCardCustomer

{

static int cnt;

public void increaseLimit()throws IOException

{

if(cnt<=3)

{

System.out.println("Enter amount limit to increse : ");

double amt=Double.parseDouble(br.readLine());

if(amt<=5000)

{

creaditLimit=creaditLimit+amt;

System.out.println("Amount limit to increse Successfully : ");

}

System.out.println("You can't increse creadit amount more than 2500 at a time ");

}

else

System.out.println("You can't increse limit more than 3 times ");

}

}

class credit

{

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

{

int ch ;

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

System.out.println("Enter the info for silver card holder : ");

SliverCardCustomer sc=new SliverCardCustomer();

sc.getdata();

System.out.println("Enter the info for Gold card holder : ");

GoldCardCustomer gc=new GoldCardCustomer();

gc.getdata();

do

{

System.out.println("1.Use silver card \n2.Pay credit for Silver card\n3.Increse limit for silver card ") ;

System.out.println("4.Use Gold card \n5.Pay credit for Gold card\n6.Increse limit for Gold card ") ;

System.out.println("0. exit") ;

System.out.println("Enter your choice : ") ;

ch=Integer.parseInt(br.readLine());

switch(ch)

{

case 1: sc.useCard();

break;

case 2:sc.payCard();

break ;

case 3:sc.increaseLimit();

break;

case 4:gc.useCard();

break;

case 5:gc.payCard();

break ;

case 6:gc.increaseLimit();

break;

case 0 :break;

}

}while(ch!=0);

}

}