meundemo.java

java写的一个反射的例子 大家看看 虽u然小 但能是说明问题

import javax.swing.JFrame;
import javax.swing.JDialog;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.lang.reflect.Constructor;
import java.util.Properties;
class mainFrame extends JFrame implements ActionListener{
	static Properties props=new Properties();
	static{
		props.setProperty("new","dialog_new");
		props.setProperty("open","dialog_open");	
	}
		JMenuBar bar=new JMenuBar();
		JMenu JMenu_file=new JMenu("file");
	    JMenuItem item1=new JMenuItem("new");
    	JMenuItem item2=new JMenuItem("open");
	mainFrame(){
		this.setJMenuBar(bar);
		bar.add(JMenu_file);
		JMenu_file.add(item1);
		JMenu_file.add(item2);
		item1.addActionListener(this);
		item2.addActionListener(this);
	}
	public void actionPerformed(ActionEvent e){
    String name=e.getActionCommand();
    String classname=props.getProperty(name);
    try {
    	Class cc=Class.forName(classname);
    	Constructor contt=cc.getDeclaredConstructor(new Class[]{mainFrame.class});
    	Object o=contt.newInstance(new Object[]{this});
    	JDialog dialog=(JDialog)o;
    	dialog.setSize(300,300);
    	dialog.setVisible(true);
	}
	catch (Exception ex) {
	}		
}
	public static void main (String[] args) {
		mainFrame mm=new mainFrame();
		mm.setSize(800,600);
		mm.setVisible(true);
	}	
}
class dialog_new extends JDialog{
	mainFrame aa;
	dialog_new(mainFrame aa){
		super(aa,"dialog_new",false);
	}
}
class dialog_open extends JDialog{
	mainFrame aa;
	dialog_open(mainFrame aa){
		super(aa,"dialog_open",true);
	}
}