内部类的用途
实现多继承
public class Goods { private valueRate = 2; private class Content implements Contents { private int i = 11 * valueRate; public int value() { return i; } } protected class GDestination implements Destination { private String label; private GDestination(String whereTo) { label = whereTo; } public String readLabel() { return label; } } public Destination dest(String s) { return new GDestination(s); } public Contents cont() { return new Content(); } }