connectapplet.java

压缩包内是近180多个针对Java初学者编写的简单实例

import java.awt.*;
import java.applet.*;
import java.net.*;
import java.awt.event.*;
public class ConnectApplet extends Applet implements ActionListener
{
	TextField textField;//声明一个文本框
	boolean badURL;//声明非法网址
	public void init()
	{
		Button button=new Button("Go"); 
		add(button);//添加一个按钮
		button.addActionListener(this);//添加按键事件
		textField=new TextField("",30);//添加文本框，长度为30
		add(textField);
		badURL=false;
	}
	public void paint(Graphics g)
	{if (badURL)
	g.drawString("Bad url!",60,130);//如果非法，则显示提示
	}
	public void actionPerformed(ActionEvent evt)
	{
		String str=textField.getText();
		try
		{
			URL url=new URL(str);
			AppletContext context=getAppletContext();
			context.showDocument(url,"_blank");//新建一个窗口转入网页
		}
		catch(MalformedURLException e)
		{
			badURL=true;
			repaint();
		}
	}
}