Question

what are the debuggers in Java?

import java.text.NumberFormat;

/**
*
* This class represents a circle that would be used as part
* of a larger geometry application
*/
public class Circle {

   private double radius;
   private NumberFormat numberFormat;
/**
*    Constructor for the Circle.
* @param radius for the circle
*/
   public Circle(double r) {
       radius = r;
   }
/**
*    This method uses the radius of the circle to compute the area.
* Math.PI is used as the value for pi.
* @return the area of the circle.
*/
   public double getArea() {
       return (radius * radius) * Math.PI;
   }
  
/**
* This method uses the radius of the circle to compute the diameter.  
* @return the diameter of the circle.
*/
   public double getDiameter() {
       return radius * 2;
   }
  
/**
* This method uses the radius of the circle to compute the circumference.
* Math.PI is used as the value for pi.
* @return the circumference of the circle.
*/
   public double getCircumference() {
       return this.getDiameter() * Math.PI;
   }
  
   /**
   *
   * @return the NumberFormat instance for the circle.
   */
  
   public NumberFormat getNumberFormat() {
       return numberFormat;
   }
   /**
   * @param args - the command line arguments. This application does not use them.
   * main method where execution begins to test the methods of the circle test.
   */
   public static void main(String[] args) {

       Circle c = new Circle(14);
      
       printCircleDetails(c);
   }

/**
*    This method prints the details of the passed in circle object to System.out.
* The passed in number formatter is used to format the circle details.
* @param c - the circle to print the details of
* @param nf - the number formatter to use when printing the details.
*/
   private static void printCircleDetails(Circle c) {
      
       System.out.println("Circle characteristics");
      
       double diameter = c.getDiameter();
       NumberFormat nf = c.getNumberFormat();
      
       System.out.println("the diameter is " + nf.format(diameter));
      
       System.out.println("the area is " + nf.format(c.getArea()));
      
       System.out.println("the circumference is " + nf.format(c.getCircumference()));
      
   }
}

Answer 1

The number representation differ from one locale to another. Internationalizing the number is one of the best solution for the application. I have modified the code. Please find the below solution.

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import java.text.NumberFormat;
import java.util.Locale;

/**
*
* This class represents a circle that would be used as part
* of a larger geometry application
*/
public class Circle {

private double radius;
private NumberFormat numberFormat;
/**
* Constructor for the Circle.
* @param radius for the circle
*/
public Circle(double r) {
radius = r;
}
/**
* This method uses the radius of the circle to compute the area.
* Math.PI is used as the value for pi.
* @return the area of the circle.
*/
public double getArea() {
return (radius * radius) * Math.PI;
}
  
/**
* This method uses the radius of the circle to compute the diameter.
* @return the diameter of the circle.
*/
public double getDiameter() {
return radius * 2;
}
  
/**
* This method uses the radius of the circle to compute the circumference.
* Math.PI is used as the value for pi.
* @return the circumference of the circle.
*/
public double getCircumference() {
return this.getDiameter() * Math.PI;
}
  
/**
*
* @return the NumberFormat instance for the circle.
*/
  
public NumberFormat getNumberFormat(Locale locale) {
   NumberFormat formatter = NumberFormat.getNumberInstance(locale);
return formatter;
}
/**
* @param args - the command line arguments. This application does not use them.
* main method where execution begins to test the methods of the circle test.
*/
public static void main(String[] args) {

Circle c = new Circle(14);
  
printCircleDetails(c);
}

/**
* This method prints the details of the passed in circle object to System.out.
* The passed in number formatter is used to format the circle details.
* @param c - the circle to print the details of
* @param nf - the number formatter to use when printing the details.
*/
private static void printCircleDetails(Circle c) {
  
System.out.println("Circle characteristics");
  
double diameter = c.getDiameter();
NumberFormat nf = c.getNumberFormat(Locale.US);
  
System.out.println("the diameter is " + nf.format(diameter));
  
System.out.println("the area is " + nf.format(c.getArea()));
  
System.out.println("the circumference is " + nf.format(c.getCircumference()));
  
}
}