Question

****Please read the following requirements and use java language w/ comments****

****Can make this a multi part question if needed****

Project requires a base class, a derived subclass, and an interactive driver (class with a main) that allows the user to utilize and manipulate the classes created. You may select one super class from the following:

              Superclass                                    Example subclasses

1. Ship class                                a) battleship, tugboat, icebreaker
2. Person class                           b) manager, salaryworker, hourlyworker
3. Aircraft class                         c) Learjet, cargoplane, fighter
4. Vehicle class                          d) car, truck, tank
5. Animal class                          e) dog, cat, bird

1. Create the “internals” for the selected superclass. This class should hold the minimum following data items:

• Appropriate properties (have at least 10 – try to select those with differing types).
• Constructors (have at least 4, ensure at least 2 have some error checking)
• Gets/Sets (build at least 6 of each)
• Utilities (A print at a minimum, you may add 1 or 2 more if desired – think this one through)
• [optional] You may create no more than 3 static methods, and 3 variables - if desired

2. Extend your base class with an appropriate subclass of your choice. Similar to your homework, add appropriate functionality.

• Add at least 2 additional data properties
• Add at least 2 additional constructors, 2 gets, and 2 sets
• Override the print utility to support your subclass specific items. You may (optionally) adjust, override, or overload any other appropriate methods.

3. In a separate class with your “main” (the driver), create a program that accomplishes the following:

• Your program should allow the creation and manipulation of an object of your subclass type.
• The program should contain a menu allowing the user to load/change (constructors/sets), delete, interrogate (retrieve data from [gets]), and print your subclass object. Obviously, you would use the subclass member methods (constructors/sets/gets/utilities) to accomplish the above requirements. Don’t have more than 10 options total
• Your menu should also include a “quit” selection – i.e. the program should loop to allow for multiple iterations. Place the program menu in a method (NON-member method, i.e. it will be in the driver class, NOT the super/sub class you created).

Answer 1

import java.io.IOException;

import java.lang.NullPointerException;

import java.util.Scanner;

class Animal {

// class properties

private int age;

private double height;

private double weight;

private String color;

private boolean isCarnivorous;

private String sex;

private int ageExpectency;

private boolean isPawed;

private boolean isDomestic;

private double speed;

// default constructor

public Animal() {

// System.out.println("Animal class constructor");

}

// parameterized constructors

// two of which are checking for valid ages

public Animal(int age) {

// "Constructing animal object with given age if greater than 0"

if(age>0) {

this.age = age;

} else {

throw new Error("Age cannot be less than zero");

}

}

public Animal(int age, double height, double weight) {

if(age>0) {

this.age = age;

this.height = height;

this.weight = weight;

} else {

throw new Error("Age cannot be less than zero");

}

}

public Animal(int age, double height, double weight, String color) {

this.age = age;

this.height = height;

this.weight = weight;

this.color = color;

}

// Getters and setters for private member variables

public int getAge() {

return age;

}

public void setAge(int age) {

this.age = age;

}

public double getHeight() {

return height;

}

public void setHeight(double height) {

this.height = height;

}

public double getWeight() {

return weight;

}

public void setWeight(double weight) {

this.weight = weight;

}

public String getColor() {

return color;

}

public void setColor(String color) {

this.color = color;

}

public boolean isCarnivorous() {

return isCarnivorous;

}

public void setCarnivorous(boolean isCarnivorous) {

this.isCarnivorous = isCarnivorous;

}

public String getSex() {

return sex;

}

public void setSex(String sex) {

this.sex = sex;

}

public int getAgeExpectency() {

return ageExpectency;

}

public void setAgeExpectency(int ageExpectency) {

this.ageExpectency = ageExpectency;

}

public boolean isPawed() {

return isPawed;

}

public void setPawed(boolean isPawed) {

this.isPawed = isPawed;

}

public boolean isDomestic() {

return isDomestic;

}

public void setDomestic(boolean isDomestic) {

this.isDomestic = isDomestic;

}

public double getSpeed() {

return speed;

}

public void setSpeed(double speed) {

this.speed = speed;

}

// class utilities

public void eat() {

System.out.println("Eating..");

}

public void sleep() {

System.out.println("Sleeping..");

}

public void print() {

System.out.println("Height: " + this.getHeight());

System.out.println("Weight: " + this.getWeight());

System.out.println("Sex: " + this.getSex());

}

// static method

public static boolean isSame(Animal a, Animal b) {

return a.equals(b);

}

}

class Dog extends Animal {

private String species;

private String petName;

// default constructor

Dog() {

// System.out.println("Dog class constructor");

}

// parameterized constructors

Dog(int age) {

super(age); // super keyword invokes super class constructor

}

Dog(int age, String species) {

super(age);

this.species = species;

}

// getter and setters for sub class properties

public String getSpecies() {

return species;

}

public void setSpecies(String species) {

this.species = species;

}

public String getPetName() {

return petName;

}

public void setPetName(String petName) {

this.petName = petName;

}

// utility methods of sub class

public void bark() {

System.out.println("Barking..");

}

// over riding super class method

@Override

public void print() {

System.out.println("Details about Dog");

System.out.println("Age: " + this.getAge());

System.out.println("Species: " + this.getSpecies());

System.out.println("Pet name: " + this.getPetName());

super.print(); // invoke super class print() method

}

}

public class Main {

public static void main(String[] args) throws IOException, NullPointerException {

Scanner in = new Scanner(System.in);

// an object of type sub class - Dog

Dog puppy = new Dog();

while(true) {

System.out.print("\nChoose an option:\n1. Create a Dog\n2. Set pet name\n3. Delete the object"

+ "\n4. Set basic details\n5. Print the object\n6. Exit\n>>>");

int option = in.nextInt();

switch(option) {

case 1:

puppy = new Dog(12, "Labrador");

continue;

case 2:

// this block will throw NullPointerException if invoked immediately after deleting dog object

// in other words, you need a dog first to set it's details

try {

in.nextLine();

System.out.print("Enter the pet name for your dog: ");

String name= in.nextLine(); //reads name

puppy.setPetName(name);

continue;

} catch(Exception e) {

System.out.println(e);

System.out.println("Create an object first");

continue; // we want the program to continue even after exception

}

case 3:

puppy = null;

continue;

case 4:

// this block will throw NullPointerException if invoked immediately after deleting dog object

// in other words, you need a dog first to set it's details

try {

System.out.print("Enter age: ");

puppy.setAge(in.nextInt());

System.out.print("Enter height: ");

puppy.setHeight(in.nextDouble());

System.out.print("Enter weight: ");

puppy.setWeight(in.nextDouble());

in.nextLine();

System.out.print("Enter Sex: ");

puppy.setSex(in.nextLine());

continue;

} catch(Exception e) {

System.out.println(e);

System.out.println("Create an object first");

continue; // we want the program to continue even after exception

}

case 5:

puppy.print();

continue;

case 6:

in.close(); // close the stream reader

System.out.println("Programs exits successfully");

return;

default:

System.out.println("Invalid input. Choose from menu");

}

}

}

}