Description
Assignment Goals
To be able to write clean, encapsulated code
To be able to use the Java API documentation to learn how to use a library class
(GregorianCalendar)
Reminders
Please use the default package in your Java project. There will be a penalty for using a named
package.
Please include a Javadoc statemnt above each method. There will be a penalty for forgetting your
Javadoc statements.
In your test cases, please use descriptive names for your test case methods and/or comments
above each test case explaining what the method tests. This will help the TAs and SAs in grading.
There will be a penalty for forgetting this step.
Overview
Our goal this week is to write clean, encapsulated code. You should aim to produce code that is well
organized, uses helper methods and interfaces where appropriate, and follows good object-oriented
design techniques. We will pay particular attention to these issues in grading your work.
This assignment is designed to help you think about where data and computations belong in a welldesigned object-oriented program. Methods that produce the right answers–but aren’t structured
well–won’t earn you many points. Figuring out where to put the various pieces of data–and what
methods you need to create to work with the data–are part of the what you are being asked to figure
out.
Although the assignment is described in two parts, you’ll only be submitting the program for Part 2.
However, we suggest you work through Part 1 as an initial implementation, then make the
modifications described in Part 2.
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Part 1: The Weather Monitoring Tool
Your overall goal in this part of the assignment is to provide a program that reports weather trends. To
keep things simple, we are interested in two trends: average daily temperature during a particular
month and total rainfall during a particular month. To this end, you need to create
a WeatherMonitor class with (at least these) two methods:
averageTempForMonth , which takes a month (designated by a number such as 1 for January, 2 for
February, etc) and a year and produces the average temperature over all days that month.*
totalRainfallForMonth , which takes a month (designated by a number such as 1 for January, 2 for
February, etc) and a year and produces the total rainfall over all days that month.*
The weather data you are tracking is initially gathered from a weather sensor. The sensor
produces Reading s containing the Time of the reading (hour and minute, both ints), the temperature
in degrees Fahrenheit (use a double), and the amount of rainfall since the last reading (use a double).
Because the volume of readings is so high, your weather monitor will store daily weather reports that
each have all of the readings for that particular day. A DailyWeatherReport contains the date (use the
Java class GregorianCalendar , see description below) and two LinkedLists: one for the temperature
readings and one for the rainfall for that day.
To manage the daily weather data, your WeatherMonitor must also provide a
method addDailyReport that consumes a date and a list of readings (nominally for that date) and
stores a daily report for the given date. For Part 1 of this assignment, the WeatherMonitor’s daily
reports should be stored in a LinkedList. (You may assume that a daily report for the provided date
does not already exist.)
(* We won’t actually require you to provide examples of daily weather reports for every single day in a
month. Your calculations of averageTempForMonth and totalRainfallForMonth should produce the
averages over all days in the month for which there are daily weather reports.)
Gregorian Calendar class
The date field for a daily weather report should be of type GregorianCalendar . This is a type available
in the java.util library. Look at the Java API (https://docs.oracle.com/javase/8/docs
/api/index.html?overview-summary.html) to learn how to use GregorianCalendar . Here are a couple of
hints to get you started:
When constructing a date for a daily weather report, use this version of
the GregorianCalendar constructor:
public GregorianCalendar (int year, int month, int dayOfMonth)
To extract individual pieces of information from objects of type GregorianCalendar , use
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the get() method (inherited from the abstract Java class Calendar ). Here’s an example of how to
extract the month:
GregorianCalendar date = new GregorianCalendar(2016, 11, 17);
int month = date.get(GregorianCalendar.MONTH); // value of month will be 11
Part 2: Protecting and Encapsulating the Data
This set of exercises asks you to modify your code from Part 1 as needed to satisfy certain goals. Do
not turn in separate code for these exercises; just modify your existing code from Part 1 as needed to
meet these goals, then turn in the final (modified) version of your code.
Thinking ahead, you know that the weather monitor program should be able to support different data
structures for the daily weather reports. Edit your code as needed to encapsulate the type of the daily
weather reports from the overall WeatherMonitor class.
A WeatherMonitor constructor should take an interface type as its argument, and any fields that hold
a DailyWeatherReport object should have an interface type.
A rogue hacker wants to modify the weather data in order to create a false panic about a pending
natural disaster. The hacker has access to a WeatherMonitor object. Edit your code as needed to
guarantee that the hacker cannot change any of the daily weather reports or their readings.
For DailyWeatherReport , please do not write methods that simply return the lists of temperatures
and/or rainfall for that day.
Something to think about: in Part 1 you were asked to define two methods,
averageTempForMonth and totalRainfallForMonth . Presumably, the code you developed for these two
methods will have some similarities. We’ve talked about why duplicating code is undesirable. Were
you able to come up with a way to eliminate the duplicate code? For those of you who took CS
1101/1102, would you have handled the task of eliminating the duplicate code differently in Racket?
Grading
Homework 5 Grading Rubric (https://canvas.wpi.edu/courses/12951/files/1898805
/download?download_frd=1)
Due to the nature of this assignment, there is no CompileCheck program to test your code against.
Your programs will not be graded against an auto-tester. When grading your programs, we will be
looking for
programs that follow the principles of encapsulation
a set of test cases to show that your code behaves as specified above
the following classes (at minimum) with appropriate fields and methods
Homework 5 – Encapsulation https://canvas.wpi.edu/courses/12951/assignments/91159
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DailyWeatherReport
Reading
Time
WeatherMonitor
at least one interface, used appropriately
The three methods in the WeatherMonitor class
( addDailyReport , avgTempForMonth , totalRainfallForMonth ), must conform to the signatures described
above.
Programs must compile in order to receive credit. Code that is commented out will not be graded.
What to Turn In
Submit (via InstructAssist (https://ia.wpi.edu/cs2102/) ) a single zip file (not tar, rar, 7zip, etc)
containing all of your .java files that contain your classes, interfaces, and examples for this
assignment. The name of the project in InstructAssist is Homework 5. Do not submit the .class files.
