MVC( 大家看看有什麼問題沒有 )

package mvc;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Random;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;

interface ModelInterface {
    void on();

    void stop();

    void setData();

    String getData();

    void changeState();

    void register(EasyObserver o);

    void notifyObservers();
}

interface ControllerInterface {
    void start();

    void stop();

    void changeState();
}

interface EasyObserver {
    void update();
}

class View extends JFrame implements ActionListener, EasyObserver {
    /**
     * 
     */
    private static final long serialVersionUID = 1L;

    private ControllerInterface controller;

    private ModelInterface model;

    private final JTextField text = new JTextField();

    private final JButton button = new JButton("Start");

    private void init() {
	this.setLocation(200, 200);
	button.addActionListener(this);
	text.setForeground(Color.RED);
	text.setEnabled(false);	
	Container c = this.getContentPane();
	c.setLayout(new BorderLayout());
	c.add(text, BorderLayout.CENTER);
	c.add(button, BorderLayout.SOUTH);
	this.pack();
	this.setResizable(false);
	this.setVisible(true);
    }

    public View(ControllerInterface controller, ModelInterface model) {
	super("MVC");
	this.controller = controller;
	this.model = model;
	model.register(this);
	this.controller.start();
	init();
	this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public void changeState() {
	if (button.getText().equals("Start"))
	    button.setText("Stop");
	else
	    button.setText("Start");
	controller.changeState();
    }

    public void actionPerformed(ActionEvent e) {
	changeState();
    }

    public void update() {
	text.setText(model.getData());
    }
}

class Controller implements ControllerInterface {

    private ModelInterface model;

    public Controller(ModelInterface model) {
	this.model = model;
    }

    public void start() {
	model.on();
    }

    public void stop() {
	model.stop();
    }

    public void changeState() {
	model.changeState();
    }
}

class Model extends Thread implements ModelInterface {

    private final Random random = new Random();

    ArrayList<EasyObserver> observers = new ArrayList<EasyObserver>();

    private volatile boolean isTrue = true;

    Object locker = new Object();

    public Model() {
    }

    public void on() {
	start();
    }

    public void run() {
	while (true) {
	    try {
		synchronized (this) {
		    while(isTrue) {
			wait();
		    }
		    notifyObservers();
		}
	    } catch (InterruptedException e) {
	    }
	}
    }

    public String getData() {
	return new Integer(Math.abs(random.nextInt())).toString();
    }

    public void register(EasyObserver t) {
	observers.add(t);
    }

    public void setData() {

    }

    public synchronized void changeState() {
	if (isTrue == true)
	    notify();
	isTrue = !isTrue;
    }

    public void notifyObservers() {
	for (EasyObserver o : observers) {
	    o.update();
	}
    }
}

public class MVC {
    public static void main(String[] args) {
	ModelInterface model = new Model();
	ControllerInterface controller = new Controller(model);
	new View(controller, model);
    }
}