package singleton;
 
public class SomeFactory {
	static private SomeFactory _instance;
 
	protected SomeFactory() {
		// ....
	}
 
	public static SomeFactory instance() {
		if (_instance == null) {
			String factoryStyle = System.getProperty("patterns.book.factoryStyle");
 
			if (factoryStyle.equals("wise")) {
				_instance = new WiseFactory(); 
			} else if (factoryStyle.equals("quick")) {
				_instance = new QuickFactory(); 
			} else {
				_instance = new SomeFactory();
			}
		}
		return _instance;
	}
 
	// Factory methods, producing products...
	public Object getProduct1() {
		// .....
		return new Object();
	}
 
	public Object getProduct2() {
		// .....
		return new Object();
	}
 
	// .....
}