Rain Effect

import java.awt.*;



public class Rain extends java.applet.Applet implements Runnable
{
private RainDrop[] rainDrops = new RainDrop[500];

Thread thread = null;
Image image;

public void init()
{
this.setForeground(new Color(137, 132, 130));
createRainDrops();
image = getImage(getDocumentBase(),getParameter("img"));
}
public void createRainDrops()
{
for(int i = 0; i < rainDrops.length; ++i)
createRainDrop(i);
}
public void createRainDrop(int index)
{
int ranX = (int) (Math.random() * 200);
int ranY = (int) (Math.random() * 150);
int ranVel = (int) (Math.random() * 10);

rainDrops[index] = new RainDrop(ranX, ranY, ranVel);
}
public final synchronized void update(Graphics g)
{
g.drawImage(image, 0, 0, this);
for(int i = 0; i< rainDrops.length; ++i)
{
rainDrops[i].paint(g);
if(rainDrops[i].x > 200 || rainDrops[i].y > 150)
createRainDrop(i);
}
}
public void paint(Graphics g)
{
g.drawImage(image, 0, 0, this);
}
public void start()
{
if(thread == null)
{
thread = new Thread(this);
thread.setPriority(thread.MAX_PRIORITY);
thread.start();
}
}
public void run()
{
while(thread != null)
{
repaint();
try
{
thread.sleep(100);
}catch(InterruptedException e){}
}
}
public void stop()
{
thread = null;
}
}

// Rain Drop class
class RainDrop
{
protected int x, y, velocity;
private static int INC = 3;

public RainDrop(int x, int y, int v)
{
this.x = x;
this.y = y;
this.velocity = v;
}

public void paint(Graphics g)
{
g.drawLine(x, y, x + INC, y + INC);
x += INC + velocity;
y += INC + velocity;
}
}