Question

Design a Ship class that has the following class members:

A field for the name of the ship

A field for the year the ship was built

A constructor

Appropriate accessors and mutators

toString method that displays the ships name and the year it was built

Design a CruiseShip class the inherits from the Ship class. Include the following members:

A field for the max number of passengers

A constructor

Appropriate accessors and mutators

toString method that overrides the Ship toString method. The method should display the ship name and the max number of passengers

Design a CargoShip class that inherits from the Ship class. Include the following members:

A field for cargo capacity (tons)

A constructor

Appropriate accessors and mutators

toString method that overrides the base class. The method should display ships name and cargo capacity.

Demonstrate these classes in a program that creates two objects from each class and stores them in an ArrayList of Ship objects. Use the following information:

Ship - NSU Vic , 1884

Ship - NSU Column, 1902

Cruise Ship - Java Queen 1, 2003, 450

Cruise Ship - CIS Minnow, 2010, 250

Cargo Ship - Demon 1, 1999, 7000

Cargo Ship - Demon 2, 1993, 10000

Step through the ArrayList and call the toString method for each object.

Answer 1

import java.util.ArrayList;

/**
*
* @author Yourname
*/
//base class
class Ship
{
//variables to store name and year
String name;
String year;
//constructor of class ship
//in this class we havent used the constructor
//variables are initialized by using setter method
public Ship()
{

}
  
//getter and setter methods
public void setName(String n)
{
name =n;
}
public String getName()
{
return name;
}
public void setYear(String y)
{
year =y;
}
public String getYear()
{
return year;
}
  
//tostring method
@Override
public String toString()
{
String detail = "Ship - "+name+", "+year+"\n";
return detail;
}
}

//cargo ship class
class CargoShip extends Ship
{
double capacity;
//in this class variables are initialized by constructor
public CargoShip(String n, String y)
{
name =n;
year = y;
}
  
//getter and setter methods
public void setCapacity(double c)
{
capacity =c;
}
public double getCapacity()
{
return capacity;
}
  
//toString method overriden
@Override
public String toString()
{
String detail = "Cargo Ship - "+name+", "+year+", "+capacity+"\n";
return detail;
}
  
}

//cruise ship class
class CruiseShip extends Ship
{
int max;
//variables initialized by using constructor
public CruiseShip(String n, String y)
{
name =n;
year=y;
}
  
//getter and setter methods
public void setMax(int m)
{
max = m;
}
public int getMax()
{
return max;
}
//override tostring method
@Override
public String toString()
{
String detail = "Cruise Ship - "+name+", "+year+", "+max+"\n";
return detail;
}
}

//driver class
public class Driver {
//main method
public static void main(String args[])
{
//make array list of type Ship class
ArrayList<Ship> al = new ArrayList<Ship>();
  
//create object of ship class and add values into it
Ship ob1 = new Ship();
ob1.setName("NSU Vic");
ob1.setYear("1884");
//insert object into array list
al.add(ob1);
  
//create second object
Ship ob2 = new Ship();
ob2.setName("NSU Column");
ob2.setYear("1902");
al.add(ob2);
  
//create object of cruise ship class and assign values into constructor
CruiseShip ob3 = new CruiseShip("Java Queen 1","2003");
ob3.setMax(450);
al.add(ob3);
  
//create second object of cruise ship class
CruiseShip ob4 = new CruiseShip("CIS Minnow","2010");
ob4.setMax(250);
al.add(ob4);
  
  
//create two objects of cargo ship class and add
//objects into array list
CargoShip ob5 = new CargoShip("Demon 1","1999");
ob5.setCapacity(7000);
al.add(ob5);
  
CargoShip ob6 = new CargoShip("Demon 2","1993");
ob6.setCapacity(10000);
al.add(ob6);
  
//print content of the array list by calling to string method
for(int i =0;i<al.size();i++)
{
System.out.println(al.get(i).toString());
}
  
}
}

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