Introduction

This assignment asks you to write and compile a simple, but complete class specification. You should also write a test driver, a main() method, that demonstrates that it functions correctly. the goal here is to reinforce your understanding of the object-oriented approach to software development.

Additionally, you'll notice that the required class makes use of Java's Exception-handling facility. Newness galore! Please think carefully about not only where the exceptional conditions can occur, but also where the Exceptions should be defined, and where they are best handled -- and what that means for the access-specifier of each of the Exception classes. facility.

The Textbook class

Please implement a class specification for a class that models aspects of a textbook might be useful for an on-line ordering system:

• The textbook's title. This shall be set at initalization and accessible, but unchangeable.
• The textbook's author. This shall be set at initalization and accessible, but unchangeable.
• The textbook's number of pages. This shall be set at initalization and accessible, but unchangeable.
• The textbook's price. It may be set at initalization (or not) and can be changed later. It is also accessible.
• Reader's comments. These can be augmented, but not changed. In other words, comments can be added, but not removed or changed.
• A method, public String toString() that returns a String which presents the members of the class in a nicely formatted way.
• A Textbook cannot have a negative price or negative number of pages. An attempt to assign these types of attributes to a Textbook should result in a NegativePagesException, or a NegativePriceException. These conditions, and the proper generation of Exceptions, should be tested within your test driver (thing tr's and catch'es).

Notes

• Items listed in italics are strong suggestions for identifier names
• Getter (Accessor) methods can simply be name, getProperty(), where "get" is literal, and "Property" is the name of the attribute.
• Setter (Mutator) methods can simply be name, setProperty(), where "set" is literal, and "Property" is the name of the attribute.
• It might make sense, or be required, to have multiple forms of the constructor, e.g. more than one constructor, each with a different parameterization