Question

Asap

Please write a Java program with comments

Asap: Please write a java program with comments Write a program that uses recursion to display concentric circles, as shown in the figure below. The circles are centered in the pane. The gap between two adjacent circles is 10 pixels, and the gap between the border of the pane and the largest circle is also 10 pixels. res

Answer 1

Below is the solution:

concentricCircles.java:

import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class concentricCircles {
   public static void main(String[] args) {
       Ovals ovalsPanel = new Ovals(); //call class to draw a circle
       JFrame newFrame = new JFrame(); //create a frame
       newFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
       newFrame.add(ovalsPanel);
       newFrame.setSize(311, 333); //set the size of the frame
       newFrame.setVisible(true);
   }
}

class Ovals extends JPanel {
   public void paintComponent(Graphics g) {
       super.paintComponent(g);
       int width = getWidth(); //width
       int height = getHeight(); //height
       System.out.printf("Width is %d \t and height is %d\n", width, height); //print the height and width
       // calculates the center of the panel
       int xPoint = width / 2;
       int yPoint = height / 2;
       drawCircles(g, 15, xPoint, yPoint); //Recursive call
   }

   private void drawCircles(Graphics g, int n, int X, int Y) {
       if (n > 0) {
           g.drawOval(X - (n * 10), Y - (n * 10), (n * 20), (n * 20)); //draw a circle
           drawCircles(g, n - 1, X,Y); //call recurrsive function
       }
   }
}

output: