Think in Java(六)：接口

传递不同的StringProcessor实现类，将会分别做不同的事情

public abstract class StringProcessor implements Processor {
	public String name() {
		return getClass().getSimpleName();
	}

	public abstract String process(Object input);

	public static String s = "If she weighs the same as a duck, she's made of wood";

	public static void main(String[] args) {
		Apply.process(new Upcase(), s);
		Apply.process(new Downcase(), s);
		Apply.process(new Splitter(), s);
	}
}

class Upcase extends StringProcessor {
	public String process(Object input) { // Covariant return
		return ((String) input).toUpperCase();
	}
}

class Downcase extends StringProcessor {
	public String process(Object input) {
		return ((String) input).toLowerCase();
	}
}

class Splitter extends StringProcessor {
	public String process(Object input) {
		return Arrays.toString(((String) input).split(" "));
	}
}

Think in Java(六)：接口

原文：http://blog.csdn.net/zdp072/article/details/43088323