Week 7: Enum, Generic Type, Streams, write to file, class diagram/16. Implement a Class Hierarchy

The class hierarchy is defined in the UML diagram below.

Implement the classes as per the diagram. 
The functionality of the methods is not tested; definitions are important.

However, the code must compile.
https://ville.utu.fi/static_resources/jubery_utufi/calculator_calculatorMachine_UML.png



<interface>
Calculator
+getResult(): double


^
-
|
|
|
|
|


CalculatorMachine
-result: double

+CalculatorMachine (result: double)
+calculate(operation: String, parameter: double): void
+getResult(); double


====================================================

import java.util.Random;
import java.lang.reflect.Field;

public class Test{
    public static void main(String[] args){
        final Random r = new Random();
        
    }
}



//ADD
interface Calculator {
  public double getResult();
}


//ADD
class CalculatorMachine implements Calculator {
  private double result;

  public CalculatorMachine(double result) {
      this.result = result;
  }
  
  public void calculate(String operation, double parameter) {
      // turn String operation into math operation
      if (operation == "+") {
          this.result = this.result + parameter;
      } 
      else if (operation == "-") {
          this.result = this.result - parameter;
      } 
      else if (operation == "*") {
          this.result = this.result * parameter;
      } 
      else if (operation == "/") {
          this.result = this.result / parameter;
      }
      else if (operation == "%") {
          this.result = this.result % parameter;
      }
  }
  
  @Override
  public double getResult() {
      return this.result;
  }

    
}



    

Testing the class CalculatorMachine...
Constructor found, CalculatorMachine object created!
Class implements the Calculator interface!

Checking attributes...
Attribute result found!
Attribute type: double
Attribute private: true

Checking methods....
getResult defined in the Calculator interface!
getResult works!
calculate works!