Inheritance - Data Structures and Problem Solving Using Java - page 180

Implement a tax payer hierarchy that consists of a TaxPayer inter-
face and the classes SinglePayer and MarriedPayer that implement the
interface.

4.49

Implement a gzip and gunzip program that performs compression and
uncompression of files.

4.50

A book consists of an author, title, and ISBN number (all of which
can never change once the topic is created).
A library book is a book that also contains a due date and the current
holder of the topic, which is either a String representing a person who
has checked the topic out or null if the topic is currently not checked
out. Both the due date and holder of the topic can change over time.
A library contains library topics and supports the following
operations:

4.51

1. Add a library book to the library.

2. Check out a library book by specifying its ISBN number and

new holder and the due date.

3. Determine the current holder of a library book given its ISBN

number.

a. Write two interfaces: Book and LibraryBook that abstract the func-

tionality described above.

b. Write a library class that includes the three methods specified. In

implementing the Library class, you should maintain the library
books in an ArrayList . You may assume that there are never any
requests to add duplicate books.

A set of classes is used to handle the different ticket types for a the-
ater. All tickets have a unique serial number that is assigned when the
ticket is constructed and a price. There are many types of tickets.

4.52

a. Design a class hierarchy that encompasses the above three classes.

b. Implement the Ticket abstract class. This class should store a serial

number as its private data. Provide an appropriate abstract method to
get the price of the ticket, provide a method that returns the serial
number, and provide an implementation of toString that prints the
serial number and price information. The Ticket class must provide a
constructor to initialize the serial number. To do so, use the following
strategy: maintain a static ArrayList<Integer> representing previously
assigned serial numbers. Repeatedly generate a new serial number
using a random number generator until you obtain a serial number
not already assigned.