HelloWorld Swing Error -JFrame

Question

Not sure why this happened. I've made no change to my computer, yet today I am unable to
compile the following code, when I was able to do it the day before. For some rease JFrame is
not understood:
My Code:
import javax.swing.*;
import java.awt.*;
public class HelloWorld extends JApplet {
SwingHelloWorldPanel m_Panel;
Create the panel and pass init to it
public void init() {
m_Panel = new SwingHelloWorldPanel();
// NOTE the call to getContentPane - this is important
getContentPane().add("Center", m_Panel);
m_Panel.init();
public void start() {
m_Panel.start();
Inner class representing a panel which does all the work
static class SwingHelloWorldPanel extends JPanel {
public void paint(Graphics g) {
super.paint(g);
Dimension size = getSize();
g.setColor(Color.lightGray);
g.fillRect(0,0,size.width,size.height);
g.setColor(Color.red);
g.drawString("Hello World",50,50);
// Override to do more interesting work
public void init() {
public void start() { }
// end inner class SwingHelloWorldPanel
Standard main for Applet/Application projects
Note that an inner class is created to to the
real work. The use of a light weight inner class
prevents inclusion of a heavyweight JApplet inside
a heavyweight container
public static void main(String args[]) {
     JFrame f = new JFrame("SwingHelloWorld");
     // Create the panel and pass init and start to it
     SwingHelloWorldPanel     hello = new SwingHelloWorldPanel();
// NOTE the call to getContentPane - this is important
     f.getContentPane().add(hello);
     hello.init();
     hello.start();
     f.setSize(300, 300);
     f.show();
The error:
C:\java_dev>javac HelloWorld.java
HelloWorld.java:71: cannot resolve symbol
symbol : constructor JFrame (java.lang.String)
location: class JFrame
JFrame f = new JFrame("SwingHelloWorld");
^
1 error
Thanks in advance

Answer 1

EXIT_ON_CLOSE has been in the API since v 1.3. Are you using an earlier version?