Question

Write ONE application program by using the following requirements: Using JAVA File input and output Exception handling Inheritance At least one superclass or abstract superclass: this class needs to have data members, accessor, mutator, and toString methods At least one subclass: this class also needs to have data members, accessor, mutator, and toString methods At least one interface: this interface needs to have at least two abstract methods At least one method overloading At least one method overriding At least one static member and one static method Polymorphism: you need to have at least one superclass reference to reference objects of a subclass At least one aggregation in a class include comments at the places where you use the above items.

Answer 1

package com.abc.others;

//superclass
public class Calculator implements ValidateInput{
   // data members
   int num1;
   int num2;

   /**
   * @param num1
   * @param num2
   */
   public Calculator(int num1, int num2) {
       super();
       validate();
       this.num1 = num1;
       this.num2 = num2;
   }

   // accessor
   /**
   * @return the num1
   */
   public int getNum1() {
       return num1;
   }

   // mutator
   /**
   * @param num1 the num1 to set
   */
   public void setNum1(int num1) {
       this.num1 = num1;
   }

   // accessor
   /**
   * @return the num2
   */
   public int getNum2() {
       return num2;
   }

   // mutator
   /**
   * @param num2 the num2 to set
   */
   public void setNum2(int num2) {
       this.num2 = num2;
   }

   // toString
   /*
   * (non-Javadoc)
   *
   * @see java.lang.Object#toString()
   */
   @Override
   public String toString() {
       return "Calculator [num1=" + num1 + ", num2=" + num2 + "]";
   }

   public int add() {
       return num1 + num2;
   }

   // Overloading
   public double add(int num1, int num2) {
       return num1 + num2;
   }

   public int sub() {
       return num1 - num2;
   }

  
   @Override
   public boolean validate() {
       // input validation exception
       if(num1 < 0 || num2 < 0)
           throw new IllegalArgumentException("Input can not be negatibe");
       return true;
   }

}

--------------
package com.abc.others;

//subclass
public class ScienceCalculator extends Calculator {
   // data members
   int num3;
   // static member
   static int callCount = 0;

   public ScienceCalculator(int num1, int num2) {
       super(num1, num2);
       // TODO Auto-generated constructor stub
   }

   // accessor
   /**
   * @return the num3
   */
   public int getNum3() {
       return num3;
   }

//mutator
   /**
   * @param num3 the num3 to set
   */
   public void setNum3(int num3) {
       this.num3 = num3;
   }

   /*
   * (non-Javadoc)
   *
   * @see java.lang.Object#toString()
   */
   @Override
   public String toString() {
       return "ScienceCalculator [num3=" + num3 + "]";
   }

   // Overriding
   public double add(double num1, double num2) {
       return num1 + num2;
   }

   public double squareRoot() {
       return Math.sqrt(num3);
   }

   // Static method
   public static double squareRoot(int num3) {
       return Math.sqrt(num3);
   }

}
------------------
package com.abc.others;

//Interface
public interface ValidateInput {
  
   public boolean validate();

}
-----------------------------
package com.abc.others;

public class CalculatorTest {

   public static void main(String[] args) {
       // TODO Auto-generated method stub
       Calculator genericCalculator = new Calculator(10,20);
      
       System.out.println(genericCalculator.add());
      
       Calculator scienceCalculator = new ScienceCalculator(20, 30);
       System.out.println(scienceCalculator.add());
      
       System.out.println(ScienceCalculator.squareRoot(9));
      
   }

}

---------
Sample output
30
50
3.0