Question

Create four classes, Trainee, JumpingCalculator, JumpingTraining, and TrainProgLoader. Save them to Trainee.java, JumpingCalculator.java, JumpingTraining.java, and TrainProgLoader.java. Code the classes as specified as follows. Compile and run to test the program.

Trainee Class: This class represents a trainee.

Fields :

A private int data field named id;

A private String data field named name; o a private boolean data field named jumpTrain; o a private static int data field named numOfTrainee;

Methods:

A constructor that takes id and name as the parameters, and increments numOfTrainee by 1

A getName method that returns the name;

A static getNumOfTrainee method that returns the numOfTrainee field;

A setJumTrain method that takes a boolean parameter and sets the jumpTrain field;

A printInfo method that prints the three data fields: id, name, jumpTrain

JumpingCalculator Class: This class conducts the calculations.

Field:

A public static final double data field name g and is given a value 9.8. It is the gravity force.

Methods:

All the following three methods take two double parameters: velocity and angle. The angle is in degree. To convert degree to radians, use double Math.toRadians(degree). Read Projectile Motion Calculator to understand how the calculations are done.

A public static method distance that return a double value as the range of projectile;

A public static method timeOfFlight that return a double value as the time of flight;

A public static method height that return a double value as the maximum height.

JumpingTraining Class: This is the jumping training class that guides the user to pass the training.

Fields:

A public static final double data field named theDistance and is given a value 100.0.

Methods:

A public static method named run that takes no parameter and return a boolean value: true for pass and false for fail. o the run method first shows information on the criteria of passing the training, then prompts the user to input two double data: the velocity and the angle in degree;

The run method then calls the three methods in JumpingCalculator class, to calculate and display the jumping distance, jumping time, and jumping height;

The run method then decides whether the user passes the training or not, by checking if the jumping distance is within the specific range (between 95.0 and 105.0 in this case).

If the user passed the training, then terminates the method and returns true;

If the user failed the training, then asks the user if he would exit or continue.

If the user chooses to continue, then read the user's input again;

If the user chooses to exit, then terminate the method and return false.

TrainProgLoader Class: This class creates trainees and loads the JumpingTraining class.

Fields:

A public static final int data field named SIZE and is given a value of 3;

Methods:

The main method that does the following:

Creates a Trainee array containing a number of SIZE trainees (in this case 3 trainees);

Create the three members of the Trainee array, with id 1, 2, 3, and name "Neo", "Morpheus", and "Trinity";

Call the currentTrainee method to obtain user's choice of the id of current trainee;

If the user is a valid trainee (id exists), say hello to him, then load the jumping training program by calling the JumpingTraining class's run method;

Assign jumping training result (true=pass, false=fail) to the trainee by calling the trainee's setjumpTrain method;

Print the latest information of the trainee by calling the trainee's printInfo method.

a public static method named currentTrainee that:

Takes a Trainee array as the parameter;

Shows the number of trainees by calling Trainee's getNumOfTrainee method;

Shows each trainee's information by calling the trainee's printInfo method;

Asks the user to choose who he is, by giving the id number;

If the user's input is valid (id exists), then return the id number as an int value;

If the user's input is invalid, then ask the user to choose again;

Answer 1

Screenshot

Program

Trainee.java

/**
* Create a class Trainee
* with id,name and test status
* Her get and set trainee details
* @author deept
*
*/
public class Trainee {
   //Attributes
   private int id;
   private String name;
   private boolean jumpTrain;
   private static int numOfTrainee;
   //Constructor
   public Trainee(int id,String name) {
       this.id=id;
       this.name=name;
       numOfTrainee+=1;
       jumpTrain=false;
   }
   //Get name of the trainee
   public String getName() {
       return name;
   }
   //Get number of trainees
   public int getNumOfTrainee() {
       return numOfTrainee;
   }
   //Get id of the trainee
   public int getId() {
       return id;
   }
   //Set trainee test result
   public void setJumpTrain(boolean jumpTrain) {
       this.jumpTrain=jumpTrain;
   }
   //Display trainee detailes
   public void printInfo() {
       System.out.print("ID: "+id+", Name: "+name+", TestPassed=");
       if(jumpTrain) {
           System.out.println("True");
       }
       else {
           System.out.println("False");
       }
   }
}

JumpingCalculator.java

/**
* Class do calculatiions
* Here find juming distane , time and height
* @author deept
*
*/
public class JumpingCalculator {
   public static final double g=9.8;
   //Method return projectile distance
   public static double distance(double velocity,double angle) {
       return (2*Math.pow(velocity,2)*Math.sin(Math.toRadians(angle))*Math.cos(Math.toRadians(angle)))/g;
   }
   //Method return time taken
   public static double timeOfFlight(double velocity,double angle) {
       return (2*velocity*Math.sin(Math.toRadians(angle)))/g;
   }
   //Method return height
   public static double height(double velocity,double angle) {
       return (Math.pow(velocity,2)*Math.pow(Math.sin((2*Math.toRadians(angle))),2))/(2*g);
   }
}

JumpingTraining.java

import java.util.Scanner;
/**
* Class to rumn a test on trainee
* @author deept
*
*/
public class JumpingTraining {
   static final double theDistance=100.00;
   //Method get velocity and angle
   //Then calculate distance and check he/she passed or failes test
   public static boolean run() {
       char ch='N';
       Scanner sc=new Scanner(System.in);
       System.out.println("Criteria to pass the test:\n   Jumping distance between 95.00 and 105.00\n");
       do {
           System.out.print("Enter velocity: ");
           double velocity=sc.nextDouble();
           System.out.print("Enter angle in degree: ");
           double angle=sc.nextDouble();
           double distance=JumpingCalculator.distance(velocity, angle);
           double timeOfFlight=JumpingCalculator.timeOfFlight(velocity, angle);
           double height=JumpingCalculator.height(velocity, angle);
           if(distance>=95.00 && distance<=105.00) {
              
               return true;
           }
           else {
               sc.nextLine();
               System.out.println(distance);
               System.out.println("You failed!!!");
               System.out.print("\nDo you want to conitnue?(Y/N): ");
               ch=Character.toUpperCase(sc.nextLine().charAt(0));
               if(ch=='N') {
                   return false;
               }
           }
       }while(ch=='Y');
       return false;
   }
}

TrainProgLoader.java

import java.util.Scanner;
/**
* Driver class Create trainess set their test status and print information
* @author deept
*
*/
public class TrainProgLoader {
   public static final int SIZE=3;

   public static void main(String[] args) {
       //Creates a Trainee array containing a number of SIZE trainees
       Trainee[] trainees=new Trainee[] {new Trainee(1,"Neo"),new Trainee(2,"Morpheus"),new Trainee(3,"Trinity")};
       //Get a trainee
       int ind=currentTrainee(trainees);
       //Say hello
       System.out.println("\nHello "+trainees[ind].getName());
       //Set his training status
       trainees[ind].setJumpTrain(JumpingTraining.run());
       //Display trainee information
       System.out.println();
       trainees[ind].printInfo();
   }
   /*
   * Get id of the trainee
   * Check valid then return it's index
   * Otherwise repeat until get correct id
   */
public static int currentTrainee(Trainee[] trainees) {
   Scanner sc=new Scanner(System.in);
   int id;
   do {
       System.out.print("Enter id of the trainee: ");
       id=sc.nextInt();
       for(int i=0;i<trainees[0].getNumOfTrainee();i++) {
           if(trainees[i].getId()==id) {
               return i;
           }
       }
       System.out.println("\nInvalid id.Please try again...");
   }while(true);
}
}

-------------------------------------------------------------------

Output

Enter id of the trainee: 4

Invalid id.Please try again...
Enter id of the trainee: 3

Hello Trinity
Criteria to pass the test:
   Jumping distance between 95.00 and 105.00

Enter velocity: 34
Enter angle in degree: 60

ID: 3, Name: Trinity, TestPassed=True