Java程序辅导

CSC207 Lab 3 — Java Classes
1 Overview
You are going to implement three Java classes. Use your new repository – the one that you are using for A1.
https://markus.teach.cs.toronto.edu/git/csc207-2016-09/YOUR USERNAME
2 Log in and get things set up in Git and Eclipse
s1 drives and s2 navigates.
In this section, you will create the directory structure for lab 3 using the command line, create a Java project
in Eclipse, create a package and three classes inside the lab 3 directory structure using Eclipse, and then
add it all to the repository using the command line.
1. Using the command line, change the current directory to your repository. (You are welcome to check
out a fresh copy, or you can use the copy you have checked out for A1.)
2. In your repository, make a lab3 directory and a lab3/src directory.
3. Start Eclipse and use the default workspace. The next set of instructions all happen within Eclipse.
(a) Create a new Java Project called Week 3 Lab. Don’t use the default location; instead, use the
lab3 directory.
(b) Create a package called week3lab.
(c) Create a new empty Java class called Author. You’ll fill it in below. In the New Java Class dialog,
set the Source folder to Week 3 Lab/src and the Package to week3lab.
(d) Create two more classes, Book and Store, in that package.
4. In the command line, add week3lab to your repository and then run git status. You should see this:
On branch master
Your branch is up-to-date with ’origin/master’.
Changes to be committed:
(use "git reset HEAD ..." to unstage)
new file: week3lab/Author.java
new file: week3lab/Book.java
new file: week3lab/Store.java
There will also be an Untracked files section, which you can ignore.
5. Commit (using a commit message such as "Setup for lab 3") and then push the changes.
3 Implement class Author
Implement class Author. This class should have two private instance variables of type String — one for
the author’s first name and another for the author’s last name.
It should also have the following methods (use Eclipse to generate these for you!):
1. A constructor that takes a first name as the first argument and a last name as the second argument.
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2. Getters and setters for the instance variables. Eclipse will generate these names: getFirstName(),
setFirstName(), getLastName(), and setLastName().
3. Override toString() so that it returns a String representation of this Author. For example, for an
author whose first name is Russel and whose last name is Winder it should return the string "Winder,
Russel".
4. Add, commit, and push your changes. Because you are still learning your way around Java and Eclipse,
you can skip writing Javadoc. Don’t skip it on your assignments, though!
4 Implement class Book
Switch roles!
Implement class Book. This class should have four private instance variables: a String to store the book
title, an array of Authors to keep track of the book’s authors, a String for the book’s ISBN, and an int for
the book’s price in cents.
It should also have the following methods:
1. A constructor that takes a book’s title, authors, ISBN number, and price, in this order.
2. Getters and setters for the instance variables: getTitle(), setTitle(), getAuthors(), setAuthors(),
getISBN(), setISBN(), getPrice(), and setPrice().
3. Override toString() so that it returns a string representation of the Book as follows: for a book
titled “Developing Java Software” with authors Russel Winder and Graham Roberts, ISBN number
978-0470090251, and price $79.75 (represented as 7995 cents), it returns the string "Developing Java
Software (978-0470090251, $79.75, by Winder, Russel and Roberts, Graham)". Call (implic-
itly or explicitly) method toString in class Author.
Add, commit, and push your changes.
4.1 Why int for the price?
Java’s floating point types are no good for representing money. Two standard basic ways of managing cash
are to keep track of cash values in cents using type int and by using java.math.BigDecimal. (There are
other approaches.) To find out more, read here:
http://stackoverflow.com/questions/3730019/why-not-use-double-or-float-to-represent-currency
We will also discuss the basics of floating-point representation toward the end of the term.
5 Implement class Store
Switch roles!
Implement class Store. Write a main method that creates a Book titled “Developing Java Software” with
authors Russel Winder and Graham Roberts, ISBN number 978-0470090251, and price $79.75, and then
prints the Book’s string representation to standard output (using System.out.println).
Also create another Book, with a different Author, and print its representation.
Add, commit, and push your changes.
Show your work to your TA.
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