for my project i have to make a winter scene using the HSA console.
I would like to try and make stars in the night sky that blink or flash, but i have no idea how i would incorperate this into the loop. Any help would be appreciated. This is what i have so far (its long and certain things need to be re touched):

// The "WinterScene" class.
import java.awt.*;
import hsa.Console;

public class WinterScene
{
static Console c; // The output console

public static void main (String[] args)
{
c = new Console ();



//background colour
Color sky= new Color (0,0,64);
c.setColor (sky);
c.fillRect (0,0,6000,6000);

c.setColor (sky);
c.fillOval (510, 70, 50,50);

Color iline = new Color (0,0,0);
c.setColor (iline);
c.drawOval (290, 320, 350, 600);

// tree trunk
Color fishrod = new Color (108, 57, 19);
c.setColor (fishrod);
c.fillRect (213, 350, 20, 60);
c.fillRect (590, 350, 20, 60);


// the snow on ground
Color ground= new Color (233,233,233);
c.setColor (ground);
c.fillRect (0,420,800,100);
c.fillOval (-100, 405, 300, 300);
c.fillOval (6, 378, 320, 290);
c.fillOval (175, 405, 300, 300);
c.fillOval (436, 395, 300, 300);

// stars
Color stars = new Color (255,255,0);
c.setColor (stars);
c.fillStar (10, 10, 20, 20);

c.fillStar (50, 80, 20, 20);
c.fillStar (100, 170, 40, 40);
c.fillStar (400, 220, 20, 20);
c.fillStar (500, 170, 20, 20);
c.fillStar (300, 100, 20, 20);

//moon
Color moon = new Color (225,249,117);
c.setColor (moon);
c.fillOval (500, 20, 100, 100);

c.setColor (sky);
c.fillOval (460, 20, 100,100);

//moon face
Color mooneye = new Color (0,0,0);
c.setColor (mooneye);
c.fillOval (568, 45, 10, 10);
c.drawOval (545, 55, 40, 40);

c.setColor (moon);
c.fillOval (558, 50, 12, 13);
c.fillOval (563, 54, 30, 30);

//part of tree that overlaps igloo

Color trees = new Color (0,79,0);
c.setColor (trees);

int [] xPoint11 = new int [4];
int [] yPoint11 = new int [4];


xPoint11[0]= 600;
yPoint11[0]= 305;
xPoint11[1]= 540;
yPoint11[1]= 360;
xPoint11[2]= 660;
yPoint11[2]= 360;
c.fillPolygon (xPoint11, yPoint11, 3);

//igloo
Color igloo = new Color (206, 237, 244);
c.setColor (igloo);
c.fillOval (290, 320, 350, 600);
c.fillRect (289, 380, 70, 50);
c.setColor (ground);
c.fillRect (289, 420, 600, 400);
c.fillOval (289, 400, 80, 30);
c.fillOval (330, 390, 70, 20);
c.fillOval (370, 400, 70, 20);
c.fillOval (410, 390, 90, 20);
c.fillOval (485, 400, 90, 20);
c.fillOval (566, 390, 40, 20);
c.fillRect (300, 405, 500, 40);
Color ihole = new Color (81, 130, 134);
c.setColor (ihole);
c.fillOval (443, 320, 40, 10);


//fishing rod

c.setColor (fishrod);
int [] xPoint1 = new int[4];
int [] yPoint1 = new int[4];

xPoint1[0] = 190;
yPoint1[0] = 410;
xPoint1[1] = 220;
yPoint1[1] = 480;
xPoint1[2] = 230;
yPoint1[2] = 480;
c.fillPolygon(xPoint1, yPoint1, 3);

//fishing hole
Color fishhole = new Color (0,128,255);
c.setColor (fishhole);
c. fillOval (115, 450, 90, 40);

//fishing line
c.setColor (mooneye);
c.drawLine (190, 410, 180, 470);


//top snowball (snowman)
c.setColor (ground);
c.fillOval (40, 250, 50, 50);

//middle snowball (snowman)
c.setColor (ground);
c.fillOval (26, 290, 80, 80);

//bottom snowball (snowman)
c.setColor (ground);
c.fillOval (18, 350, 100, 100);
c.setColor (mooneye);
c.drawOval (18, 350, 100, 100);
c.setColor (ground);
c.fillOval (39, 330, 53, 50);

// snowman eyes
c.setColor (mooneye);
c.fillOval (52, 267, 10, 10);
c.fillOval (67, 266, 10, 10);

//snowman hat
c.setColor (mooneye);
c.fillRect (41, 226, 42, 32);
c.fillRect (23, 256, 80, 5);
Color stripe = new Color (252, 45, 39);
c.setColor (stripe);
c.fillRect (41, 248, 42, 10);

//snowman smile
c.setColor (mooneye);
c.fillOval (48, 280, 5, 5);
c.fillOval (50, 284, 5, 5);
c.fillOval (53, 288, 5, 5);
c.fillOval (57, 291, 5, 5);
c.fillOval (62, 292, 5, 5);
c.fillOval (67, 291, 5, 5);
c.fillOval (71, 288, 5, 5);
c.fillOval (74, 284, 5, 5);
c.fillOval (76, 280, 5, 5);

//snowman buttons
Color button = new Color (255, 0, 128);
c.setColor (button);
c.fillOval (60, 310, 10, 10);
Color button1 = new Color (47, 151, 255);
c.setColor (button1);
c.fillOval (60, 328, 10, 10);
c.setColor (button);
c.fillOval (60, 346, 10, 10);

//snowman arms
c.setColor (fishrod);
//int [] xPoint2 = new int[4];
//int [] yPoint2 = new int[4];

// xPoint2[0] = 190;
//yPoint2[0] = 410;
//xPoint2[1] = 220;
//yPoint2[1] = 480;
//xPoint2[2] = 230;
//yPoint2[2] = 480;
//c.fillPolygon(xPoint2, yPoint2, 3);

//christmas trees

c.setColor (trees);

int [] xPoint4 = new int [4];
int [] yPoint4 = new int [4];

xPoint4[0]= 220;
yPoint4[0]= 275;
xPoint4[1]= 180;
yPoint4[1]= 304;
xPoint4[2]= 260;
yPoint4[2]= 304;
c.fillPolygon (xPoint4, yPoint4, 3);

int [] xPoint5 = new int [4];
int [] yPoint5 = new int [4];

xPoint5[0]= 220;
yPoint5[0]= 290;
xPoint5[1]= 160;
yPoint5[1]= 330;
xPoint5[2]= 280;
yPoint5[2]= 330;
c.fillPolygon (xPoint5, yPoint5, 3);

int [] xPoint6 = new int [4];
int [] yPoint6 = new int [4];

xPoint6[0]= 220;
yPoint6[0]= 290;
xPoint6[1]= 145;
yPoint6[1]= 365;
xPoint6[2]= 295;
yPoint6[2]= 365;
c.fillPolygon (xPoint6, yPoint6, 3);

//christmas tree 2

int [] xPoint7 = new int [4];
int [] yPoint7 = new int [4];

xPoint7[0]= 600;
yPoint7[0]= 220;
xPoint7[1]= 580;
yPoint7[1]= 260;
xPoint7[2]= 620;
yPoint7[2]= 260;
c.fillPolygon (xPoint7, yPoint7, 3);

int [] xPoint8 = new int [4];
int [] yPoint8 = new int [4];

xPoint8[0]= 600;
yPoint8[0]= 250;
xPoint8[1]= 570;
yPoint8[1]= 280;
xPoint8[2]= 630;
yPoint8[2]= 280;
c.fillPolygon (xPoint8, yPoint8, 3);

int [] xPoint9 = new int [4];
int [] yPoint9 = new int [4];

xPoint9[0]= 600;
yPoint9[0]= 270;
xPoint9[1]= 560;
yPoint9[1]= 300;
xPoint9[2]= 640;
yPoint9[2]= 300;
c.fillPolygon (xPoint9, yPoint9, 3);

int [] xPoint10 = new int [4];
int [] yPoint10 = new int [4];

xPoint10[0]= 600;
yPoint10[0]= 285;
xPoint10[1]= 550;
yPoint10[1]= 330;
xPoint10[2]= 650;
yPoint10[2]= 330;
c.fillPolygon (xPoint10, yPoint10, 3);

// christmas tree decorations

Color Cstar = new Color (255, 128, 0);
c.setColor (Cstar);
c.fillStar (208, 254, 25, 25);

int r, g, b;
for (int i=1; i<900000000; i++)
{
r = (int) (Math.random () * 255);
g = (int) (Math.random () * 255);
b = (int) (Math.random () * 255);

Color clr = new Color (r,g,b);
c.setColor (clr);
c.fillOval (200, 300, 10, 10);
c.fillOval (212, 282, 10, 10);
c.fillOval (212, 320, 10, 10);
c.fillOval (183, 316, 10, 10);
c.fillOval (230, 307, 10, 10);
c.fillOval (238, 325, 10, 10);
c.fillOval (179, 334, 10, 10);
c.fillOval (162, 349, 10, 10);
c.fillOval (200, 340, 10, 10);
c.fillOval (225, 335, 10, 10);
c.fillOval (250, 338, 10, 10);
c.fillOval (270, 350, 10, 10);
c.fillOval (237, 353, 10, 10);
c.fillOval (212, 320, 10, 10);
c.fillOval (180, 352, 10, 10);
c.fillOval (215, 351, 10, 10);
c.fillOval (230, 292, 10, 10);

try {
Thread.sleep(600); // do nothing for 1000 miliseconds (1 second)
}
catch (InterruptedException e)
{
e.printStackTrace();
}

}