策略模式

Strategy.java

import static com.mceiba.util.Print.*;
import java.util.*;

interface Processor{
	String name();
	Object process(Object input);
}
class StringProcessor implements Processor{
	public String name(){
		return getClass().getSimpleName();
	}
	public Object process(Object input) { return input; }
}
class Upcase extends StringProcessor{
	public String process(Object input){ //Covariant return
		return ((String)input).toUpperCase();
	}
}
class Downcase extends StringProcessor{
	public String process(Object input){ //Covariant return
		return ((String)input).toLowerCase();
	}
}
class Splitter extends StringProcessor{
	public String process(Object input){ //Covariant return
		return Arrays.toString(((String)input).split(" "));
	}
}
public class Strategy{
	public static void process(Processor pro, Object obj){
		println("Using Processor "+pro.name());
		println(pro.process(obj));
	}
	public static String str = "Beautiful is better than ugly";
	public static void main(String[] args){
		process(new Upcase(), str);
		process(new Downcase(), str);
		process(new Splitter(), str);
	}
}