Description
Overview: You will write a program this week that is composed of three classes: the first class
defines ConicalFrustum objects, the second class defines ConicalFrustumList objects, and the third,
ConicalFrustumListApp, reads in a file name entered by the user then reads the list name and
ConicalFrustum data from the file, creates ConicalFrustum objects and stores them in an ArrayList,
creates a ConicalFrustumList object with the list name and ArrayList, prints the ConicalFrustumList
object, and then prints summary information about the ConicalFrustumList object.
A Conical Frustum is a Frustum created by slicing the top off a cone (with the cut made parallel to
the base), forming a lower base and an upper base that are circular and parallel.
r1 radius of top
r2 radius of bottom
h height
s slant height
S lateral surface area
V volume
A total surface area
V = π ∗ h
3 (r*
+ + r+
+ + (r* ∗ r+))
s = /(r* − r+)+ + h+
S = π * (r1 + r2) * s
A = π * (r12 + r22 + (r1 + r2) * s)
Source for figures and formulas: https://www.calculatorsoup.com/images/frustum001.gif
• ConicalFrustum.java (assuming that you successfully created this class in Project 4, just
copy the file to your new Project 5 folder and go on to ConicalFrustumList.java on page 4.
Otherwise, you will need to create ConicalFrustum.java as part of this project.)
Requirements: Create a ConicalFrustum class that stores the label, radius of top, radius of
bottom, and height where the radii and height are non-negative. The ConicalFrustum class also
includes methods to set and get each of these fields, as well as methods to calculate the volume,
slant height, lateral surface area, and total surface area of a ConicalFrustum object, and a method
to provide a String value that describes a ConicalFrustum object.
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Design: The ConicalFrustum class has fields, a constructor, and methods as outlined below.
(1) Fields (instance variables): label of type String, radius1 of type double, radius2 of type
double, and height of type double. Initialize the String to “” and the double
variables to 0 in their respective declarations. These instance variables should be private so
that they are not directly accessible from outside of the ConicalFrustum class, and these
should be the only instance variables (fields) in the class.
(2) Constructor: Your ConicalFrustum class must contain a public constructor that accepts four
parameters (see types of above) representing the label, radius1, radius2, and height. Instead
of assigning the parameters directly to the fields, the respective set method for each field
(described below) should be called since they are checking the validity of the parameter. For
example, instead of using the statement label = labelIn; use the statement
setLabel(labelIn); Below are examples of how the constructor could be used to
create ConicalFrustum objects. Note that although String and numeric literals are used for
the actual parameters (or arguments) in these examples, variables of the required type could
have been used instead of the literals.
ConicalFrustum example1 = new ConicalFrustum(“Small”, 0.5, 0.75, 0.25);
ConicalFrustum example2 = new ConicalFrustum(” Medium “, 5.1, 10.2, 15.9);
ConicalFrustum example3 = new ConicalFrustum(“Large”, 98.32, 199.0, 250.0);
(3) Methods: Usually a class provides methods to access and modify each of its instance
variables (known as get and set methods) along with any other required methods. The
methods for ConicalFrustum, which should each be public, are described below. See the
formulas in the figure above and the Code and Test section below for information on
constructing these methods.
o getLabel: Accepts no parameters and returns a String representing the label field.
o setLabel: Takes a String parameter and returns a boolean. If the String
parameter is not null, then the “trimmed” String is set to the label field and the
method returns true. Otherwise, the method returns false and the label is not set.
o getRadius1: Accepts no parameters and returns a double representing the radius1
field.
o setRadius1: Takes a double parameter and returns a boolean. If the double
parameter is non-negative, then the parameter is set to the radius1 field and the method
returns true. Otherwise, the method returns false and the radius1 field is not set.
o getRadius2: Accepts no parameters and returns a double representing the radius2
field.
o setRadius2: Takes a double parameter and returns a boolean. If the double
parameter is non-negative, then the parameter is set to the radius2 field and the method
returns true. Otherwise, the method returns false and the radius2 field is not set.
o getHeight: Accepts no parameters and returns a double representing the height
field.
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o setHeight: Accepts a double parameter and returns a boolean as follows. If the
double parameter is non-negative, then the parameter is set to the height field and the
method returns true. Otherwise, the method returns false and the height field is not
set.
o volume: Accepts no parameters and returns the double value for the volume of the
ConicalFrustum. [Be sure to avoid integer division in your expression.]
o slantHeight: Accepts no parameters and returns the double value for the slant height
of the ConicalFrustum.
o lateralSurfaceArea: Accepts no parameters and returns the double value for
the lateral surface area of the ConicalFrustum. Be sure to call your slantHeight
method as appropriate.
o totalSurfaceArea: Accepts no parameters and returns the double value for the
total surface area of the ConicalFrustum. Be sure to call your slantHeight method as
appropriate.
o toString: Returns a String containing the information about the ConicalFrustum
object formatted as shown below, including decimal formatting (“#,##0.0##”) for the
double values. Newline and tab escape sequences should be used to achieve the proper
layout. In addition to the field values (or corresponding “get” methods), the following
methods should be used to compute appropriate values in the toString method:
volume(), slantHeight(), lateralSurfaceArea(), and
totallSurfaceArea(). Each line should have no trailing spaces (e.g., there should
be no spaces before a newline (\n) character). The toString value for example1,
example2, and example3 respectively are shown below (the blank lines are not part
of the toString values).
ConicalFrustum “Small” with radius1 = 0.5, radius2 = 0.75, and height = 0.25 has:
volume = 0.311 cubic units
slant height = 0.354 units
lateral surface area = 1.388 units
total surface area = 3.941 square units
ConicalFrustum “Medium” with radius1 = 5.1, radius2 = 10.2, and height = 15.9 has:
volume = 3,031.546 cubic units
slant height = 16.698 units
lateral surface area = 802.608 units
total surface area = 1,211.172 square units
ConicalFrustum “Large” with radius1 = 98.32, radius2 = 199.0, and height = 250.0 has:
volume = 18,020,568.788 cubic units
slant height = 269.512 units
lateral surface area = 251,739.485 units
total surface area = 406,518.914 square units
Code and Test: As you implement your ConicalFrustum class, you should compile it and then
test it using interactions. For example, as soon you have implemented and successfully compiled
the constructor, you should create instances of ConicalFrustum in interactions (e.g., copy/paste
the examples on page 2). Remember that when you have an instance on the workbench, you can
unfold it to see its values. You can also open a viewer canvas window and drag the instance from
the Workbench tab to the canvas window. After you have implemented and compiled one or
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more methods, create a ConicalFrustum object in interactions and invoke each of your methods
on the object to make sure the methods are working as intended. You may find it useful to create
a separate class with a main method that creates an instance of ConicalFrustum then prints it out.
This would be similar to the ConicalFrustumApp class you will below, except that in the
ConicalFrustumApp class you will read in the values and then create and print the object.
• ConicalFrustumList.java
Requirements: Create a ConicalFrustumList class that stores the name of the list and an
ArrayList of ConicalFrustum objects. It also includes methods that return the name of the list,
number of ConicalFrustum objects in the ConicalFrustumList, total surface area, total volume,
average surface area, and average volume for all ConicalFrustum objects in the
ConicalFrustumList. The toString method returns a String containing the name of the list
followed by each ConicalFrustum in the ArrayList, and a summaryInfo method returns summary
information about the list (see below).
Design: The ConicalFrustumList class has two fields, a constructor, and methods as outlined
below. These instance variables should be private, and they should be the only instance variables
(fields) in the class.
(1) Fields (or instance variables): (1) a String representing the name of the list and (2) an
ArrayList of ConicalFrustum objects. These are the only fields (or instance variables) that
this class should have.
(2) Constructor: Your ConicalFrustumList class must contain a constructor that accepts a
parameter of type String representing the name of the list and a parameter of type ArrayList<
ConicalFrustum> representing the list of ConicalFrustum objects. These parameters should
be used to assign the fields described above (i.e., the instance variables).
(3) Methods: The methods for ConicalFrustumList are described below.
o getName: Returns a String representing the name of the list.
o numberOfConicalFrustums: Returns an int representing the number of
ConicalFrustum objects in the ConicalFrustumList. If there are zero ConicalFrustum
objects in the list, zero should be returned.
o totalSurfaceArea: Returns a double representing the total surface areas for all
ConicalFrustum objects in the list. If there are zero ConicalFrustum objects in the list,
zero should be returned.
o totalVolume: Returns a double representing the total volumes for all ConicalFrustum
objects in the list. If there are zero ConicalFrustum objects in the list, zero should be
returned.
o averageSurfaceArea: Returns a double representing the average for the total
surface area for all ConicalFrustum objects in the list. If there are zero ConicalFrustum
objects in the list, zero should be returned.
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o averageVolume: Returns a double representing the average volume for all
ConicalFrustum objects in the list. If there are zero ConicalFrustum objects in the list,
zero should be returned.
o toString: Returns a String (does not begin with \n) containing the name of the list
followed by each ConicalFrustum in the ArrayList. In the process of creating the return
result, this toString() method should include a while loop that calls the toString() method
for each ConicalFrustum object in the list (adding a \n before and after each). Be sure to
include appropriate newline escape sequences. For an example, see lines 3 through 21 in
the output below from ConicalFrustumListApp for the ConicalFrustum_data_1.txt input
file. [Note that the toString result should not include the summary items in lines 24
through 29 of the example. These lines represent the return value of the summaryInfo
method below which will be called from main.]
o summaryInfo: Returns a String (does not begin or end with \n) containing the name of
the list (which can change depending of the value read from the file) followed by various
summary items: number of ConicalFrustums, total surface area, total volume, average
surface area, and average volume. Use “#,##0.0##” as the pattern to format the double
values. For an example, see lines 24 through 29 in the output below from
ConicalFrustumListApp for the ConicalFrustum_data_1.txt input file. The second
example below shows the output from ConicalFrustumListApp for the
ConicalFrustum_data_0.txt input file which contains a list name but no ConicalFrustum
data.
Code and Test: Remember to import java.util.ArrayList. The totalSurfaceArea and
totalVolume methods each requires that you use a while loop to retrieve each object in the
ArrayList. As you implement your ConicalFrustumList class, you can compile it and then test it
using interactions. Alternatively, (1) you can create a class with a simple main method that
creates a ConicalFrustumList object and calls its methods; or (2) you can create the
ConicalFrustumListApp described next.
• ConicalFrustumListApp.java
Requirements: Create a ConicalFrustumListApp class with a main method that reads in the
name of the data file entered by the user and then reads list name and ConicalFrustum data from
the file, creates ConicalFrustum objects, stores them in a local ArrayList of ConicalFrustum
objects, creates a ConicalFrustumList object with the name of the list and the ArrayList of
ConicalFrustum objects, and then prints the ConicalFrustumList object followed summary
information about the ConicalFrustumList object. All input from the keyboard (System.in)
and output to the screen (System.out) for this project must be done in the main method.
• Design: The main method should prompt the user to enter a file name, and then read in the file
name with a Scanner on System.in. A second Scanner should be created with the file
name and then be used to read in the data file (see the Code section below for details). The first
record (or line) in the file contains the name of the list. This is followed by the data for the
ConicalFrustum objects. After each set of ConicalFrustum data is read in, a ConicalFrustum
object should be created and stored in the local ArrayList of ConicalFrustum objects. After the
file has been read in and the ArrayList has been populated, the main method should create a
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ConicalFrustumList object with the name of the list and the ArrayList of ConicalFrustum objects
as parameters in the constructor. It should then print the ConicalFrustumList object, then print
the summary information about the ConicalFrustumList (i.e., print the value returned by the
summaryInfo method for the ConicalFrustumList). The output from two runs of the main
method in ConicalFrustumListApp is shown below. The first is produced after reading in the
ConicalFrustum_data_1.txt file, and the second is produced after reading in the
ConicalFrustum_data_0.txt file. Your program output should be formatted exactly as shown.
Line # Program output
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
—-jGRASP exec: java ConicalFrustumListApp
Enter file name: conical_frustum_data_1.txt
Conical Frustum Test List
ConicalFrustum “Small” with radius1 = 0.5, radius2 = 0.75, and height = 0.25 has:
volume = 0.311 cubic units
slant height = 0.354 units
lateral surface area = 1.388 units
total surface area = 3.941 square units
ConicalFrustum “Medium” with radius1 = 5.1, radius2 = 10.2, and height = 15.9 has:
volume = 3,031.546 cubic units
slant height = 16.698 units
lateral surface area = 802.608 units
total surface area = 1,211.172 square units
ConicalFrustum “Large” with radius1 = 98.32, radius2 = 199.0, and height = 250.0 has:
volume = 18,020,568.788 cubic units
slant height = 269.512 units
lateral surface area = 251,739.485 units
total surface area = 406,518.914 square units
—– Summary for Conical Frustum Test List —–
Number of ConicalFrustum Objects: 3
Total Surface Area: 407,734.026
Total Volume: 18,023,600.645
Average Surface Area: 135,911.342
Average Volume: 6,007,866.882
—-jGRASP: operation complete.
Line # Program output
1
2
3
4
5
6
7
8
9
10
11
12
—-jGRASP exec: java ConicalFrustumListApp
Enter file name: conical_frustum_data_0.txt
Conical Frustum Empty Test List
—– Summary for Conical Frustum Empty Test List —–
Number of ConicalFrustum Objects: 0
Total Surface Area: 0.0
Total Volume: 0.0
Average Surface Area: 0.0
Average Volume: 0.0
—-jGRASP: operation complete.
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Code: Remember to import java.util.ArrayList, java.util.Scanner, and java.io.File, and
java.io.FileNotFoundException prior to the class declaration. Your main method declaration
should indicate that your main method throws FileNotFoundException.
After your program reads in the file name from the keyboard, it should read in the data file using
a Scanner object that was created on a file using the file name entered by the user.
… = new Scanner(new File(fileName));
You can assume that the first line in the data file is the name of the list, and then each set of four
lines contains the data from which a ConicalFrustum object can be created. After the name of the
list has been read and assigned to a local variable, a while loop should be used to read in the
ConicalFrustum data. The boolean expression for the while loop should be
(_________.hasNext()) where the blank is the name of the Scanner you created on the
file. Each iteration through the loop reads four lines (see note 3 below). As each of the lines is
read from the file, the respective local variables for the ConicalFrustum data items (label, radius,
and cylinder height) should be assigned, after which the ConicalFrustum object should be created
and added to a local ArrayList of ConicalFrustum objects. The next iteration of the loop should
then read the next set of three lines then create the next ConicalFrustum object and add it to the
local ArrayList of ConicalFrustum objects, and so on. After the file has been processed (i.e.,
when the loop terminates after the hasNext method returns false), name of the list and the
ArrayList of ConicalFrustum objects should be used to create a ConicalFrustumList object. The
list should be printed by printing a leading \n and the ConicalFrustumList object. Finally, the
summary information is printed by printing a leading \n and the value returned by the
summaryInfo method invoked on the ConicalFrustumList object.
Test: You should test your program minimally (1) by reading in the ConicalFrustum_data_1.txt
input file, which should produce the first output above, and (2) by reading in the
ConicalFrustum_data_0.txt input file, which should produce the second output above. Although
your program may not use all of the methods in ConicalFrustumList and ConicalFrustum, you
should ensure that all of your methods work according to the specification. You can either user
interactions in jGRASP or you can write another class and main method to exercise the methods.
Web-CAT will test all methods to determine your project grade.
General Notes
1. All input from the keyboard and all output to the screen should done in the main method.
Only one Scanner object on System.in should be created and this should be done in the main
method. All printing (i.e., using the System.out.print and System.out.println methods) should
be in the main method. Hence, none of your methods in the ConicalFrustum class should do
any input/output (I/O).
2. ConicalFrustum_data_1.txt and ConicalFrustum_data_0.txt – Be sure to download the data
files and store them in same folder as your source files. You should find the data files in the
jGRASP Browse tab and then open each data file in jGRASP to see the items that your
program will be reading from the file. Be sure to close the data files without changing them.
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3. Reading the data from the input file – Since each of the data items for label, radius1, radius2,
and height are on separate lines, within the while loop, each line should be read with a
.nextLine() on the file Scanner and then parsed into a double when appropriate. Below is an
example where label, radius1, radius2, and height are local variables and the blank should be
filled in with the variable for the Scanner for the input file.
label = _______.nextLine();
radius1 = Double.parseDouble(_______.nextLine());
radius2 = Double.parseDouble(_______.nextLine());
height = Double.parseDouble(_______.nextLine());
