Question

Now design a class named PassengerJet in the file named PassengerJet.java as a subclass of Jet implemented in Problem 2 above.
This class should include the following attributes (fields):

l numPassengers that represents the number of passengers the jet can carry. l numEngines: The number of engines the Jet has l hasAutopilot: The aircraft has full autopilot capabilities. Additionally, write the following methods: l isHardToFly: This returns a Boolean. The jet is hard to fly if there is no autopilot. l needsLongRunway: This returns true if the grossEmptyWeight is greater than 500000 lbs. Also include at least one constructor that makes sense. Don’t forget to implement the Comparable interface in this class if you left it out of Jet and chose to do it at this level. Remember that you are inheriting some or all (depending on how you designed your superclass) of the attributes and methods defined in its superclass (Jet). Now, write a main method in this class that tests your implementation of PassengerJet.

Answer 1

Hi,

Please find the below code according to the problem statement:

Note: As the Jet class specifications are not provided in the problem statement, sample Jet class is considered for the implementation of PassengerJet class

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PAssengerJet.java

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public class PassengerJet extends Jet implements Comparable<PassengerJet> {

   private int numPassengers;
   private int numEngines;
   private boolean hasAutoPilot;

   public boolean isHardToFly() {
       if (!hasAutoPilot)
           return true;
       return false;
   }

   /**
   * @param manufacturer
   * @param grossWeightEmpty
   * @param model
   * @param year
   * @param owner
   * @param lastOverhaul
   * @param numOverhauls
   * @param maxRecommendedFlightHours
   * @param numPassengers
   * @param numEngines
   * @param hasAutoPilot
   */
   public PassengerJet(String manufacturer, double grossWeightEmpty, String model, int year, String owner,
           int lastOverhaul, int numOverhauls, int maxRecommendedFlightHours, int numPassengers, int numEngines,
           boolean hasAutoPilot) {
       super(manufacturer, grossWeightEmpty, model, year, owner, lastOverhaul, numOverhauls,
               maxRecommendedFlightHours);
       this.numPassengers = numPassengers;
       this.numEngines = numEngines;
       this.hasAutoPilot = hasAutoPilot;
   }

   public boolean needsLongRunWay() {
       if (super.getGrossWeightEmpty() > 500000)
           return true;
       return false;
   }

   /*
   * implementing the comparable interface for the PassengerJet using number of
   * passengers in that Jet.
   * The Passenger Jet which can have higher passenger is considered the bigger one
   *
   * @see java.lang.Comparable#compareTo(java.lang.Object)
   */
   @Override
   public int compareTo(PassengerJet o) {
       return this.numPassengers-o.numPassengers;
   }

  
   public static void main(String[] args) {
      
       PassengerJet pJet = new PassengerJet("Boeing", 650000, "747", 2015, "Asiana", 8, 2, 25, 1000, 2, true);
      
       PassengerJet pJet2 = new PassengerJet("Lockheed",450000,"DC-10",2017,"Rockwell Collins",7,3,16,750,2,false);
      
       System.out.println("Passenger Jet-1 is hard to fly : "+pJet.isHardToFly());
       System.out.println("Passenger Jet-1 needs a long runway to land : "+pJet.needsLongRunWay());
       System.out.println("***************************");
       System.out.println("Passsenger Jet 2 is hard to fly : "+pJet2.isHardToFly());
       System.out.println("Passenger Jet-2 needs a long runway to land : "+pJet2.needsLongRunWay());
       System.out.println("***************************");
       System.out.println("Passenger Jet-1 comare to Passenger Jet-2 : "+pJet.compareTo(pJet2));
      
   }
}

Sample output:

e Console X <terminated> PassengerJet [Java Application] C:\Program Files\Java\jdk-11.0.1\bin\javaw.exe (Jun Passenger Jet-1 is hard to fly : false Passenger Jet-1 needs a long runway to land : true ********** *** Passsenger Jet 2 is hard to fly : true Passenger Jet-2 needs a long runway to land : false *************************** Passenger Jet-1 comare to Passenger Jet-2 : 250

I Hope this helps you!!

Thanks