"我们可以在任何现有类之上添加新的接口，所以这意味着让方法接受接口类型，是一种让任何类都可以对该方法进行适配的方式。"
demo:
有一个未实现Readable的类，让Scanner作用于它
public class RandomDoubles { private static Random rand = new Random(47); public double next(){ return rand.nextDouble(); } public static void main(String[] args) { RandomDoubles rd = new RandomDoubles(); for(int i = 0; i < 7; i++){ System.out.println(rd.next() + " "); } } }
public class AdaptedRandomDoubles extends RandomDoubles implements Readable { private int count; public AdaptedRandomDoubles(int count){ this.count = count; } @Override public int read(CharBuffer cb) throws IOException { if(count-- == 0){ return - 1; } String result = Double.toString(next()) + " "; cb.append(result); return result.length(); } public static void main(String[] args) { Scanner s = new Scanner(new AdaptedRandomDoubles(7)); while(s.hasNextDouble()){ System.out.println(s.nextDouble() + " "); } } }
原文：http://www.cnblogs.com/919czzl/p/6340502.html