applet中的线程

import java.applet.Applet;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
public class AppletThreadDemo extends Applet {
	class MyThread1 extends Thread {
		public void run() {
			Graphics g = getGraphics();
			g.setFont(new Font("Arial", Font.BOLD, 30));
			for (char ch = 'A'; ch <= 'Z'; ++ch) {
				g.setColor(Color.black);
				g.drawString(String.valueOf(ch), 50, 70);
				g.drawString(String.valueOf((int) ch), 285, 70);
				try {
					sleep(500);
				} catch (InterruptedException e) {
					getAppletContext().showStatus("Error");
				}
				g.setColor(getBackground());
				g.drawString(String.valueOf(ch), 50, 70);
				g.drawString(String.valueOf((int) (ch)), 285, 70);
			}
		}
	}
	class MyThread2 extends Thread {
		public void run() {
			Graphics g = getGraphics();
			g.setFont(new Font("Arial", Font.BOLD, 30));
			for (char ch = 'a'; ch <= 'z'; ++ch) {
				g.setColor(Color.black);
				g.drawString(String.valueOf(ch), 50, 120);
				g.drawString(String.valueOf((int)ch), 285, 120);
				try {
					sleep(500);
				} catch (InterruptedException e) {
					getAppletContext().showStatus("Error");
				}
				g.setColor(getBackground());
				g.drawString(String.valueOf(ch), 50, 120);
				g.drawString(String.valueOf((int)ch), 285, 120);
			}
		}
	}
	public void paint(Graphics g) {
		g.setFont(new Font("Arial", Font.BOLD, 30));
		g.drawString("ASCII", 80, 68);
		g.drawString("ASCII", 80, 120);
		new MyThread1().start();
		new MyThread2().start();
	}
}