import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.geom.Point2D;
import java.awt.geom.Ellipse2D;

/**
This class implements a circle and a boolean function to
test if a user-given point is inside this circle.
*/
public class Circle
{
/**
  Constructs a circle.
  @param x the x-coordinate of the center
  @param y the y-coordinate of the center
  @param r the radius
  @param aColor the color
*/
public Circle(double x, double y, double r, Color aColor)
{
  xCenter = x;
  yCenter = y;
  radius = r;
  color = aColor;
}

/**
  Draws a circle and a point.
  @param g2 the graphics content
*/
public void draw(Graphics2D g2)
{
  g2.setColor(color);
  Ellipse2D.Double circle
     = new Ellipse2D.Double(xCenter - radius, yCenter - radius,
        2 * radius, 2 * radius);
  g2.draw(circle);
}

/**
  Determine if point is inside or outside the circle
  @param p the point to test if it is inside the circle
  @return true if the point is inside the circle
*/
public boolean isInside(Point2D.Double p)
{
  . . .    <--- CODE needed
}

private double xCenter;
private double yCenter;
private double radius;
private Color color;
}

import java.awt.Graphics2D;
import java.awt.geom.Point2D;
import java.awt.geom.Ellipse2D;
import javax.swing.JOptionPane;

/**
Draws a circle and a point. The point is colored green if it falls
inside the circle, red otherwise.
*/
public class CircleComponent extends JComponent
{
public CircleComponent(Point2D.Double point)
{
  circle = new Circle(200, 200, 100, Color.BLACK);
  final double SMALL_RADIUS = 3;
  Color color;
  if(. . .)
     . . .
  else
     . . .
  smallCircle = new Circle(point.getX(), point.getY(), SMALL_RADIUS, color);
}

public void paintComponent(Graphics g)
{
  Graphics2D g2 = (Graphics2D) g;
  circle.draw(g2);
  smallCircle.draw(g2);
}

private Circle circle;
private Circle smallCircle;
}