Re: Java Threads Question

mearvk wrote:

You version was not compliable (Mediator is missing)
nor runnable (no main()). This variant, that compares your
method and my method, is both compilable and runnable.
<sscce>
import javax.swing.*;
import java.awt.*;
import javax.swing.AbstractAction;
import java.awt.event.*;
import java.util.concurrent.locks.ReentrantLock;

class JPasswordDialog extends JDialog
{
        Mediator mediator=null;

        JPanel mainPanel=null;
        JPanel usernamePanel=null;
        JPanel passwordPanel=null;
        JPanel buttonPanel=null;
        JLabel usernameL=null;
        JLabel passwordL=null;
        JTextField usernameTF=null;
        JPasswordField passwordTF=null;
        JButton login=null;
        JButton cancel=null;

        public static void main(String[] args) {
            JFrame f = new JFrame("Log In");
            f.setDefaultCloseOperation(
                JFrame.DISPOSE_ON_CLOSE);
            f.setLocationRelativeTo(null);

            final JPasswordDialog jpd = new
                JPasswordDialog(f,
                    "Enter Password", new Mediator());

            Container c = f.getContentPane();
            c.setLayout(new GridLayout(0,1));

            final JTextField username = new JTextField();
            username.setEditable(false);

            final JTextField password = new JTextField();
            password.setEditable(false);

            JButton b1 = new JButton("Prompt");
            b1.addActionListener( new ActionListener(){
                public void actionPerformed(ActionEvent ae) {
                    System.out.println("Hi!");
                    jpd.prompt();
                    username.setText( jpd.getUsername() );
                    password.setText( jpd.getPassword() );
                    System.out.println("Bye!");
                }
            } );
            c.add(b1);

            JButton b = new JButton("Log In");
            b.addActionListener( new ActionListener(){
                public void actionPerformed(ActionEvent ae) {
                    System.out.println("Hi!");
                    jpd.setVisible(true);
                    username.setText( jpd.getUsername() );
                    password.setText( jpd.getPassword() );
                    System.out.println("Bye!");
                }
            } );
            c.add(b);
            c.add(username);
            c.add(password);

            f.pack();
            f.setVisible(true);
        }

        PasswordDialogOKAction passwordDialogOKAction=null;

        public JPasswordDialog(JFrame owner, String title, Mediator m)
        {
                super(owner, title, true);
                this.mediator=m;

                instantiateComponents();
                initMainPanel();
                initUsernamePanel();
                initPasswordPanel();
                initButtonPanel();
                this.add(mainPanel);

                setResizable(false);
                setBounds(owner.getX()+owner.getWidth()/2-125,
owner.getY()+owner.getHeight()/2-65,250,130);
        }

        public String[] prompt()
        {
                setVisible(true);

                try
                {
                        synchronized (passwordDialogOKAction.lock)
                        {
                                wait();
                        }
                }
                catch(Exception e)
                {
                        System.err.println(e);
                }

                return new String[]{getUsername(),getPassword()};
        }

        public JTextField getUsernameTextField()
        {
                return usernameTF;
        }

        public JTextField getPasswordField()
        {
                return passwordTF;
        }

        public synchronized String getUsername()
        {
                return usernameTF.getText();
        }

        public synchronized String getPassword()
        {
                return new String(passwordTF.getPassword());
        }

        private void instantiateComponents()
        {
                mainPanel=new JPanel();
                usernamePanel=new JPanel();
                passwordPanel=new JPanel();
                buttonPanel=new JPanel();
                usernameL=new JLabel("Username: ");
                passwordL=new JLabel("Password: ");
                usernameTF=new JTextField();
                passwordTF=new JPasswordField();
                login=new JButton("Login");
                cancel=new JButton("Cancel");
        }

        private void initMainPanel()
        {
                mainPanel.setLayout(new GridLayout(3,1,0,0));

mainPanel.setBorder(BorderFactory.createEmptyBorder(10,10,10,10));
                mainPanel.add(usernamePanel);
                mainPanel.add(passwordPanel);
                mainPanel.add(buttonPanel);
        }

        private void initUsernamePanel()
        {
                usernamePanel.setLayout(null);
                usernameL.setBounds(0,0,70,20);
                usernameTF.setBounds(80,0,145,20);
                usernamePanel.add(usernameL);
                usernamePanel.add(usernameTF);
        }

        private void initPasswordPanel()
        {
                passwordPanel.setLayout(null);
                passwordL.setBounds(0,0,70,20);
                passwordTF.setBounds(80,0,145,20);
                passwordPanel.add(passwordL);
                passwordPanel.add(passwordTF);
        }

        private void initButtonPanel()
        {
                buttonPanel.setLayout(new GridLayout(1,2,15,15));
                buttonPanel.add(login);
                buttonPanel.add(cancel);
                login.setAction((passwordDialogOKAction=new
PasswordDialogOKAction("Login",this, mediator)));
                cancel.setAction(new
PasswordDialogCancelAction("Cancel",this));
        }

}

class PasswordDialogOKAction extends AbstractAction
{
        Mediator mediator=null;
        JPasswordDialog dialog=null;

        public ReentrantLock lock=new ReentrantLock();

        public PasswordDialogOKAction(String name, JPasswordDialog
dialog,
Mediator m)
        {
                super(name);
                this.dialog=dialog;
                this.mediator=m;
                lock.lock();
        }

        public void actionPerformed(ActionEvent ae)
        {
                if(dialog.getUsername().length()<0 ||
dialog.getUsername().length()>20)
                {
                        JOptionPane.showMessageDialog(dialog, "Invalid
Username.");
                        lock.unlock();
                        return;
                }

                if(dialog.getPassword().length()<0 ||
dialog.getPassword().length()>20)
                {
                        JOptionPane.showMessageDialog(dialog, "Invalid
Password.");
                        lock.unlock();
                        return;
                }

                dialog.dispose();
        }

}

class PasswordDialogCancelAction extends AbstractAction
{
        JPasswordDialog dialog=null;

        public PasswordDialogCancelAction(String name, JPasswordDialog
dialog)
        {
                super(name);
                this.dialog=dialog;
        }

        public void actionPerformed(ActionEvent ae)
        {
                dialog.dispose();
        }

}

class Mediator {
    Mediator() {
    }
}
</sscce>

Andrew T.