Illegal start of expression problem

Question

In my app I' creating an action listener to check for the click of a button, but this is my first try with an action listener and i'm having a few issues. I'll give you the part of the program that goes before where I get the error.
import javax.swing.SpringLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import java.awt.Container;
import java.awt.Toolkit;
import java.awt.Dimension;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class BattleSystem implements ActionListener {
    private static void createAndShowGUI() {
         int number = 10;
         int secondNumber = 5;
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);
        //Create and set up the window.
        JFrame frame = new JFrame("System");
        Toolkit theKit = frame.getToolkit();
        Dimension wndSize = theKit.getScreenSize();
        frame.setBounds(wndSize.width/4, wndSize.height/4,
                            wndSize.width/4, wndSize.width/4);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Set up the content pane.
        Container contentPane = frame.getContentPane();
        SpringLayout layout = new SpringLayout();
        contentPane.setLayout(layout);
        //Buttons
        JButton attack = new JButton("Clcik here!");
        attack.addActionListener(this);
        //Health Labels
        JLabel label = new JLabel("Number 1:  " + number);
        JLabel eLabel = new JLabel("Number 2:  " + secondNumber);
        //Handle Button Events
        public void actionPerformed(ActionEvent e) {
             number--;
             secondNumber--;
        }It gives me the error illegal start of expression at this line:
public void actionPerformed(ActionEvent e) {
How can I get this to work?
On a differnt question how can I stop the user being able to resize the application window?
Finally, can you depot Java Applications (not Applets) or do they ahve to be an applet to use them outside the compiler?

Answer 1

where i come from we say
"this just ain't right"
but i understand that you are new to java.
if you don't understand the modifications then you will have some
problems. you need to go through the problems one by one.
the modifications fix compiler errors but that doesn't mean it will work.
I think you have had bad advice in the past. after you think about it,
then if you have specific questions, then post applicable code and
tell us what the problem is and if it is due to compiler error or
runtime exception. give appropriate output.
public class BattleSystem implements ActionListener {
    private int health;//modified
    private int enemyHealth;//modified
    public BattleSystem(){
        health = 10; //added
         enemyHealth = 5;//added
    private static void createAndShowGUI() {
        BattleSystem bs = new BattleSystem();//added
         //health = 10; deleted
         //enemyHealth = 5;deleted
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);
        //Create and set up the window.
        JFrame frame = new JFrame("Battle System");
        Toolkit theKit = frame.getToolkit();
        Dimension wndSize = theKit.getScreenSize();
        frame.setBounds(wndSize.width/4, wndSize.height/4,
                            wndSize.width/4, wndSize.width/4);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Buttons
        JButton attack = new JButton("Attack!");
        attack.addActionListener(bs);//modified
        //Health Labels
        JLabel healthLabel = new JLabel("Health: " + bs.health);//modified
        JLabel eHealthLabel = new JLabel("Enemy Health: " + bs.enemyHealth);//modified
        //Set up the content pane.
        Container contentPane = frame.getContentPane();
        SpringLayout layout = new SpringLayout();
        contentPane.setLayout(layout);
        //Add the labels to the frame
        contentPane.add(healthLabel);
        contentPane.add(eHealthLabel);
        contentPane.add(attack);
        //Adjust constraints for the eHealthLabel so its pos is 145,0
          layout.putConstraint(SpringLayout.WEST, eHealthLabel,
                     145,
                     SpringLayout.WEST, contentPane);
          layout.putConstraint(SpringLayout.NORTH, eHealthLabel,
                     0,
                     SpringLayout.NORTH, contentPane);
          //Adjust constraints for the Attack so its pos is 145,0
          layout.putConstraint(SpringLayout.WEST, attack,
                     0,
                     SpringLayout.WEST, contentPane);
          layout.putConstraint(SpringLayout.NORTH, attack,
                     25,
                     SpringLayout.NORTH, contentPane);
        //Display the window.
        frame.setVisible(true);
        //Handle Button Events
        public void actionPerformed(ActionEvent e) {
             health--;
             enemyHealth--;
    public static void main(String[] args) {
        //Runs the program securely and shows GUI
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
}