import java.awt.event.*;
import java.io.*;
import java.util.Properties;
import javax.swing.*;

/**
Properties的练习
*/
public class Sample extends JApplet
{
	public static void main(String[] args)
	{
		PropertiesFrame frame = new PropertiesFrame();
		frame.setVisible(true);
	}
}
class PropertiesFrame extends JFrame
{
	public PropertiesFrame()
	{
		String userDir = System.getProperty("user.home");
		File propertiesDir = new  File(userDir,".corejava");
		if(!propertiesDir.exists())
		{
			propertiesDir.mkdir();
		}
		propertiesFile = new File(propertiesDir,"program.properties");

		Properties defaultSettings = new Properties();
		defaultSettings.put("left","0");
		defaultSettings.put("top","0");
		defaultSettings.put("width",""+DEFAULT_WIDTH);
		defaultSettings.put("height",""+DEFAULT_HEIGHT);
		defaultSettings.put("title","");
		settings = new Properties(defaultSettings);
		if(propertiesFile.exists())
		{
			try
			{
				FileInputStream in = new FileInputStream(propertiesFile);
				settings.load(in);
			}
			catch (IOException ex)
			{
				ex.printStackTrace();
			}
		}
		int left = Integer.parseInt(settings.getProperty("left"));
		int top = Integer.parseInt(settings.getProperty("top"));
		int width = Integer.parseInt(settings.getProperty("width"));
		int height = Integer.parseInt(settings.getProperty("height"));
		setBounds(left,top,width,height);
		String title = settings.getProperty("title");
		if(title.equals(""))
		{
			title = JOptionPane.showInputDialog("Please supply a frame title:");
		}
		if(title == null)
		{
			title = "";
		}
		setTitle(title);
		addWindowListener(new WindowAdapter(){
			public void windowClosing(WindowEvent event)
			{
				settings.put("left",""+getX());
				settings.put("top",""+getY());
				settings.put("width",""+getWidth());
				settings.put("height",""+getHeight());
				settings.put("title",getTitle());
				try
				{
					FileOutputStream out = new FileOutputStream(propertiesFile);
					settings.store(out,"Program Properties");
				}
				catch (IOException ex)
				{
					ex.printStackTrace();
				}
				System.exit(0);
			}
		});
	}
	private File propertiesFile;
	private Properties settings;
	public static final int DEFAULT_WIDTH = 300;
	public static final int DEFAULT_HEIGHT = 200;
}