Question

In java, design a class named Motorcycle that has the following fields:

• year – The year field is an int that holds the motorcycle’s year

• make – The make field references a String object that holds the make of the motorcycle.

• speed – The speed field is an int that holds the motorcycle’s current speed

The class should have the following constructor and other methods:

• Constructor – the constructor should accept the motorcycle’s year and make as arguments. These values should be

assigned to the object's year and make fields. The constructor should also assign 0 to the speed field.

• Accessors (getters) – Appropriate accessor methods should get the values stored in an objects year, make, and speed

fields.

• accelerate – the accelerate method should add 5 to the speed field each time it is called

• brake – the break method should subtract 5 from the speed field each time it is called.

Demonstrate the Motorcycle class in a program that creates a Motorcycle object, and then calls the accelerate method four times. After each call to the accelerate method, get the current speed of the motorcycle and display it. Then call the brake method three times. After each call to the brake method, get the current speed of the motorcycle and display it.

Create a UML class diagram for the Motorcycle class & include javadoc comments for each methods.

A sample run of demo program:

Enter the year your motorcycle was made

(User inputs year)

Enter the make of your motorcycle

(User inputs brand name)

Then Program prints to screen:

A 2017 (user inputted brand name) going 0.0 miles per hour.

A 2017 (user inputted brand name) going 10.00 miles per hour.

A 2017 (user inputted brand name) going 15.00 miles per hour.

A 2017 (user inputted brand name) going 10.00 miles per hour.

Answer 1

Hi,

Please find below code as per your requirement.

Added driver class MotorcycleTest.java to test functionality.

Let me know if you have any doubt/concern in answer via comments.

Hope this answer helps you.

Thanks.

/***********************JAVA CODE**********************/

/********************Motorcycle.java**********************/

/**
* This class used to perform accelerate and brake operation on motorcycle
*
*/
public class Motorcycle {

   //instance variable
   private int year;
   private String make;
   private int speed;

   /**
   * Parameterized constructor which accepting 2 parameters and speed set to 0.
   * @param year - year of motorcycle
   * @param make - make of motorcycle
   */
   public Motorcycle(int year, String make) {
       this.year = year;
       this.make = make;
       this.speed = 0;
   }

   /**
   * This is getter method for year
   * @return the year
   */
   public int getYear() {
       return year;
   }

   /**
   * This is getter method for make
   * @return the make
   */
   public String getMake() {
       return make;
   }

   /**
   * This is getter method for speed
   * @return the speed
   */
   public int getSpeed() {
       return speed;
   }

   /**
   * This method used to increase speed by 5.
   */
   public void accelerate() {
       this.speed += 5;
   }

   /**
   * This method used to decrease the speed by 5 till 0.
   */
   public void brake() {
       if(this.speed <= 0) {
           this.speed = 0;
       } else {
           this.speed -= 5;
       }
   }

}

/********************MotorcycleTest.java**********************/

import java.util.Scanner;

/**
* This class is driver class for Motorcycle class to test functionality
*
*/
public class MotorcycleTest {

   /**
   * This main method is starting point of this driver class which contains code to be tested.
   * @param args
   */
   public static void main(String[] args) {

       //Scanner class is used to take user input from console.
       Scanner sc = new Scanner(System.in);
      
       //Prompting user to give input for year
       System.out.print("Enter the year your motorcycle was made :");
       //Storing user input in variable
       int year = sc.nextInt();
      
       //Prompting user to give input for make
       System.out.print("Enter the make of your motorcycle :");
       //Storing user input in variable
       String make = sc.next();
      
       //Created class using constructor with user input given above
       Motorcycle motorcycle = new Motorcycle(year, make);
      
       //Calling accelerate method 4 times each time printing speed of motorcycle
       motorcycle.accelerate();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
       motorcycle.accelerate();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
       motorcycle.accelerate();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
       motorcycle.accelerate();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
      
       //Calling brake method 3 times each time printing speed of motorcycle
       motorcycle.brake();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
       motorcycle.brake();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
       motorcycle.brake();
       System.out.println("A "+year+" "+make+" going "+ motorcycle.getSpeed() +" miles per hour.");
      
   }

}