singleton class instance , use volatile

ImageLoader.java

	private volatile static ImageLoader instance;

	/** Returns singleton class instance */
	public static ImageLoader getInstance() {
		if (instance == null) {
			synchronized (ImageLoader.class) {
				if (instance == null) {
					instance = new ImageLoader();
				}
			}
		}
		return instance;
	}

	protected ImageLoader() {
	}