utility.java

斜45度游戏《NetIntruder》

package isoj2me;

import java.util.*;

import javax.microedition.lcdui.*;

/**
 * <p>
 * isoj2me: Utility
 * </p>
 * <p>
 * This class contains utility methods.
 * </p>
 * <p>
 * Copyright: Copyright (c) 2006
 * </p>
 * <p>
 * License: Lesser GPL (http://www.gnu.org)
 * </p>
 * <p>
 * Company: <a href=http://www.mondonerd.com target="_blank">Mondonerd.com</a>
 * </p>
 * 
 * @author Massimo Maria Avvisati
 * @version 0.5
 */

public class Utility {
	public Utility() {
	}

	/**
	 * This method return an Image loading it from the "hard disk" of the mobile
	 * phone (from the standard directory) or, if the image was already loaded,
	 * it return an image took from an hashtable
	 * 
	 * @param imageCode
	 *            alphanumeric code for this image (filename)
	 * @param imagesHash
	 *            where to store Image objects
	 * @return the requested Image
	 */
	private static Image temp_image;
	public static Image loadImage(String imageCode, Hashtable imagesHash) {

        if (imagesHash == null) {
            imagesHash = new Hashtable();
        }
        if (imagesHash.size() > 12) { //TODO
            imagesHash.clear();
            //System.gc();
            //System.out.println("Cache (" + imagesHash.toString() + ") empty");
        }
        
		if (imagesHash.containsKey(imageCode)) {
			return (Image) imagesHash.get(imageCode);
		} else {
			
			try {
				temp_image = Image.createImage("/" + imageCode + ".png");
                //System.out.println("Loaded: " + "/" + imageCode + ".png");
				imagesHash.put(imageCode, temp_image);
                if (temp_image != null) {
				return (Image) imagesHash.get(imageCode);
                } else {
                    System.gc();
                    imagesHash.clear();
                    temp_image = Image.createImage("/" + imageCode + ".png");
                    //System.out.println("Loaded extra: " + "/" + imageCode + ".png");
                    imagesHash.put(imageCode, temp_image);
                    return (Image) imagesHash.get(imageCode);
                }
			} catch (Exception ex) {
				System.out.println("loadImage Error can't load " + imageCode
						+ ":" + ex);
			}
		}

        Image temp = Image.createImage(1, 1);
		return temp;
	}
    
   

}