►Assignment 1: Java finger exercises
Assignment 1: Java finger exercises
1 Purpose
2 Getting started
3 Adding a class
4 Adding a method
5 Grading standards
5.1 The style guide
6 Submission
6.1 Deliverables
6.2 Instructions
6.7

Assignment 1: Java finger exercises

Due: Mon 09/19 at 8:59pm; self-evaluation due Tue 09/20 at 8:59pm

Starter files: code.zip

1 Purpose

The primary goal of this assignment is to get you writing Java (again or for the first time). As a secondary goal, completing this assignment will help you ensure that you have a properly configured and working Java development environment and IDE, and that you can use the submission system (to be described elsewhere).

2 Getting started

Before you start this assignment, you should make sure that you’ve set up a proper CS 3500 environment. More detailed instructions about how to do this are coming soon, but until then this might help:

3 Adding a class

This part of the assignment is a continuation of the code written in Lecture 2: The essence of objects. In particular, you will write a Java class Webpage (in package cs3500.hw01.publication) that implements the Publication interface from lecture, with the same functionality as web page objects created by the ISL+λ function new-webpage, as seen in the lecture notes.

  1. Write a class Webpage that implements the Publication interface. It must define a public constructor:

    public Webpage(String title, String url, String retrieved)

    The signature of the constructor, including the order of the arguments, is important to enable automated-test–based grading for functional correctness. Don’t forget to write a good Javadoc comment. See how to cite a webpage in MLA and APA style by looking at the Racket code in Lecture 2.

  2. Write a JUnit 4 test class, WebpageTest, that tests both public methods of Webpage.

4 Adding a method

Compared to the version from class this week, there are two changes in the code for this homework:

To complete this assignment:

  1. You must write sufficient tests to be confident that your implementation of the format method is correct. Your tests should exercise every non-trivially distinct possibility.

    It is recommended that you write these tests before attempting to implement the format method as specified below. Doing so will help you clarify how the method is supposed to work.

    The autograder for this portion of the homework is slightly tricky, and requires your code to be designed in a particular way. First, your tests must be placed in the AbstractDurationFormatTest class, and you must leave unchanged the portion of the file marked "Leave this section alone". Second, do not explicitly use new in your tests: as we did in class, use the hms and sec methods to construct examples of Durations.

    The autograder will run your tests against several new Duration classes with deliberately-buggy format implementations, and against one perfectly-correct implementation; to earn full credit on this autograder, you must have sufficient tests to catch all of these bugs. In other words, you will succeed on this homework if you write enough correct tests to comprehensively check the format method, such that at least one fails on any buggy implementation of it, but all tests pass on the correct implementation. Remember: test failures are good things!

  2. You must implement the Duration.format(String) method in the appropriate place(s). Your implementation must not use any of the string replacement methods such as replace or replaceAll. (We strongly suggest that you use iteration and not recursion to process a string.) The Javadoc description of this method is a sufficient specification for this method, but requires careful attention: an overly-hasty reading will probably miss some edge cases.

    The autograder will also test your implementation for correctness, regardless of whether you wrote your own test cases.

5 Grading standards

For this assignment, you will be graded on

5.1 The style guide

Coding style is important. For this class we follow Google’s Java style guide. It’s comprehesive but not very long, so I suggest reading the whole thing and then referring to it as needed.

While it can’t yet take on full responsibility for formatting code—much less for programming style more broadly—your IDE may be able to help you follow the code formatting portion of the style guide:

6 Submission

6.1 Deliverables

Your submission should include

Do ensure that your code compiles. Half of your grade is for correctness as determined by automated testing, so code that doesn’t compile is subject to a 50% penalty up front.

6.2 Instructions

You will submit your homework at https://cs3500.ccs.neu.edu. Log in with your CCS username and password. If you do not have one, you cannot submit your homework, so obtain one immediately and email the course staff. Once logged in, you will need to enter some simple profile information (name and nickname, mostly), and upload a picture of yourself so we recognize you. After completing that profile, you’ll be taken to a page like this one:

In this screen: