Write a Java program that simulates a traffic light. The program lets the user select one of three lights: red, yellow, or green with radio buttons. On selecting a button, an appropriate message with “Stop” or “Ready” or “Go” should appear above the buttons in selected color. Initially, there is no message shown.

 import java.awt.Color;

import java.awt.*;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;

import javax.swing.*;

class App extends JFrame implements ItemListener{
	JFrame actualWindow;
	JPanel messageContainer, lightsContainer;
	JLabel message;
	ButtonGroup btn_group;
	JRadioButton rb_red, rb_yellow, rb_green;
	
	App() {
		Font myFont = new Font("Verdana",Font.BOLD, 50);
		actualWindow = new JFrame("Traffic Lights");
		messageContainer = new JPanel();
		lightsContainer = new JPanel();
		message = new JLabel("");
		btn_group = new ButtonGroup();
		rb_red = new JRadioButton("Red");
		rb_yellow = new JRadioButton("Yellow");
		rb_green = new JRadioButton("Green");
		
		actualWindow.setLayout(new GridLayout(2, 1));
		
		message.setFont(myFont);
		rb_red.setForeground(Color.RED);
		rb_yellow.setForeground(Color.YELLOW);
		rb_green.setForeground(Color.GREEN);
		
		btn_group.add(rb_red);
		btn_group.add(rb_yellow);
		btn_group.add(rb_green);
		
		rb_red.addItemListener(this);
		rb_yellow.addItemListener(this);
		rb_green.addItemListener(this);
		
		messageContainer.add(message);
		lightsContainer.add(rb_red);
		lightsContainer.add(rb_yellow);
		lightsContainer.add(rb_green);
		
		actualWindow.add(messageContainer);
		actualWindow.add(lightsContainer);
				
		actualWindow.setSize(300, 200);
		actualWindow.setVisible(true);
	}

	@Override
	public void itemStateChanged(ItemEvent ie) {
		JRadioButton selected = (JRadioButton) ie.getSource();
		String textOnButton = selected.getText();
		if(textOnButton.equals("Red")) {
			message.setForeground(Color.RED);
			message.setText("STOP");
		} else if(textOnButton.equals("Yellow")) {
			message.setForeground(Color.YELLOW);
			message.setText("READY");
		} else {
			message.setForeground(Color.GREEN);
			message.setText("GO");
		}
	}
}
public class TrafficLight {
	public static void main(String[] args) {
		new App();
	}
}

Write a Java program that handles all mouse events and shows the event name at the center of the window when a mouse event is fired .

Program Code:

import javax.swing.event.*;

import java.awt.event.*;

import java.awt.*;

import javax.swing.JApplet;

public class mouseevnts extends JApplet implements MouseListener

{

private int x,y;

private String event;

public void init()

{

setLayout(new FlowLayout());

x=-1;

addMouseListener(this);

}

public void paint(Graphics g)

{

super.paint(g);

g.drawRect(0,0,getWidth(),getHeight());

if(x!=1)

{

g.drawString("Mouseevent is"+event+"("+x+","+y+")", 10,50);

}

}

public void mousePressed(MouseEvent e)

{

x=e.getX();

y=e.getY();

event="pressed";

repaint();

}

public void mouseClicked(MouseEvent e)

{

x=e.getX();

y=e.getY();

event="clicked";

repaint();

}

public void mouseReleased(MouseEvent e)

{

x=e.getX();

y=e.getY();

event="Reeleased";

repaint();

}

public void mouseExited(MouseEvent e)

{

x=e.getX();

y=e.getY();

event="Exited";

repaint();

}

public void mouseEntered(MouseEvent e)

{

x=e.getX();

y=e.getY();

event="Entered";

repaint();

}

}