showpickle.java

《JAVA与模式》附书中源代码

package com.javapatterns.serializable.instantiate;

import java.awt.*;
import java.awt.event.*;
import java.beans.*;

/**
 *
 * The purpose of this class is to display a set of buttons
 * which were previously serialized in order to demostrate the
 * use of the "instantiate" method provided by the Beans class.
 * In order to execute this program, use the following command:
 *
 *    java ShowButtons [file basename #1] [file basename #2]...
 *
 * For example, If you had a green, 16-point Start button; a
 * yellow, 20-point Yield button; and a red, 30-point Stop
 * button; then the following command would apply:
 *
 *    java ShowButton Start16G Yield20Y Stop30R
 *
 * The file names of the serialized buttons must end in 
 * ".ser".  However, the extension should not be specified
 * as part of the command arguments.  There is not limit on
 * the number of buttons to display.
 *
 */
class ShowPickle extends Frame
{

	/**
	 *
	 * This method constructs a frame window, changes its layout to 
	 * FlowLayout and adds all of the serialized buttons specified on  
	 * the command line.
	 *
	 * @param      serButton      Array of file names for the
	 *                            serialized buttons.
	 *
	 */
	ShowPickle(String serComponent)
	{
	
		/*
		* Invoke the super class constructor, add an event listener
		* for the "close" event and change the layout to "Flow".
		*/
		super("Show Pickle");
		addWindowListener(new win());
		setLayout(new FlowLayout());
		
		/*
		* Instantiate the serialized button.  If the process
		* does not work for a particular button, then display an error
		* and instantiate a regular button.
		*/
		TextField text;
		
		try
		{
		  text = (TextField)Beans.instantiate(null, serComponent);
		}
		catch (Exception e)
		{
		   System.out.println(e);
		   text = new TextField();
		}
		add(text);
	}

	/**
	 *
	 * This method creates a frame to display the list of
	 * serialized buttons.  The button components are packed into
	 * the frame.
	 * 
	 * @param      args     Array of base file names for the
	 *                      serialized buttons.  The ".ser"
	 *                      extension should be omitted.
	 */
	public static void main(String[] args)
	{

	   Frame frame = new ShowPickle("mytextfield");
	   frame.pack();
	   frame.setVisible(true);
	
	}
	
	
	/**
	 *
	 * This "inner" class listens for the event which indicates that
	 * the window is closing.  
	 *
	 */
	class win extends WindowAdapter
    {
		/**
		 *
		 * This method handles the event which indicates that a window
		 * is closing. If encountered, then it hides the frame, frees
		 * the resources and exits.
		 *
		 * @param   evt         Event object
		 */
		public void windowClosing(WindowEvent evt)
        {
			Frame frame = (Frame)evt.getSource();
			frame.setVisible(false);
			frame.dispose();
			System.exit(0);
		}
	}
}