Traffic Light using Applet in Java | algorithm and source code

Traffic Light using Applet in Java | algorithm and source code

Traffic signal automation using java.

Aim: To design Traffic Light using Applet in Java

Procedure for Traffic Light Design:

  1. To design the TLD se the packages by importing it from  java. applet,  awt,  awt. Event
  2. Use Applet implements ItemListener,
  3. init() create the CheckboxGroup() and Checkbox() add it to addItemListener()
  4. Use repaint() to call the paint method repeatedly until certain condition.
  5. Paint method design signal using drawOval()
  6. Alter the signal using setColor(Color.red/green/orange)

import java.awt.*;
import java.applet.*;
import java.awt.event.*;
/*<applet code=”Traffic” width=700 height=600>
</applet>*/
public class Traffic extends Applet implements Runnable
{
Thread t;
int i=0,a=0,j=0;
public void start()
{
t=new Thread(this);
t.start();
}
public void run()
{
for(i=20;i>=0;i–)//countdown
{
try
{
Thread.sleep(1000);
}
catch(Exception e)
{
System.out.println(e);
}
if(i<=20 && i>3)//red
{
a=1;
repaint();
}
else
if(i<=3 && i>0)//yelloe
{
a=2;
repaint();
}
else
if(i==0)//green
{
for(j=0;j<20;j++)
{
a=3;
try
{
Thread.sleep(1000);
}
catch(Exception e)
{
System.out.println(e);
}
repaint();
}
if(j==20)//end of green(return to red)
{
run();
}
}
}
repaint();
}
public void paint(Graphics g)
{
g.setColor(Color.black);//pole top
g.fillRect(150,150,50,150);
g.drawRect(150,150,50,150);
g.setColor(Color.black);//POLE UP
g.fillRect(150,150,50,150);
g.drawRect(150,150,50,150);
g.setColor(Color.black);//POLE DOWN
g.fillRect(165,300,20,155);
g.drawRect(165,300,20,155);
g.drawOval(150,150,50,50);//RED
g.drawOval(150,200,50,50);//YELLOW
g.drawOval(150,250,50,50);//GREEN
g.setColor(Color.red);//COUNTDOWN STOP
g.drawString(“”+i,50,50);
if(a==1)//REDSIGNAL
{
g.setColor(Color.red);
g.fillOval(150,150,50,50);
g.drawOval(150,150,50,50);
g.drawString(“STOP”,50,150);
}
if(a==2)//YELLOWSIGNAL
{
g.setColor(Color.yellow);
g.fillOval(150,200,50,50);
g.drawOval(150,200,50,50);
g.drawString(“READY”,50,200);
}
if(a==3)//GREENSIGNAL
{
g.setColor(Color.blue);//countdown
g.drawString(“”+j,150,50);
g.setColor(Color.green);
g.fillOval(150,250,50,50);
g.drawOval(150,250,50,50);
g.drawString(“GO”,50,250);
}
}
}

Output:

Traffic Light using Applet in Java | algorithm and source code

Traffic Light using Applet in Java | algorithm and source code

https://en.wikipedia.org/wiki/Java_applet

https://en.wikipedia.org/wiki/Traffic_light

Leave a Comment

Your email address will not be published. Required fields are marked *