比较有意思的一个模式

package org.cxz.designPattern.combo;

import java.io.BufferedInputStream;
import java.util.Properties;

public abstract class Father {
	private static final String configFilePath = "config.properties";
	private static final String key = "className";
	protected static String _className = null;
	static {
		try {
			Properties props = new Properties();
			props.load(new BufferedInputStream(Father.class
					.getResourceAsStream(configFilePath)));
			_className = props.getProperty(key);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public abstract void doBusiness();

	public static Father getInstance() {
		Father f = null;
		try {
			f = (Father) Class.forName(_className).newInstance();
		} catch (InstantiationException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		} catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return f;
	}
}

在程序中不需要关注具体的实现类。

package org.cxz.designPattern.combo;


public class Main2 {
	public static void main(String[] args) {
		Father.getInstance().doBusiness();
	}
}

package org.cxz.designPattern.combo;

public class Son extends Father {

	@Override
	public void doBusiness() {
		System.out.println("Do Business");
	}

}

className=org.cxz.designPattern.combo.Son