我知道我们可以使用接口从多个类继承,但是可以继承状态吗?
如果你确定你关心的方法在接口中,那么你可以有一个实现接口的类,然后委托给“超类”的实例:
interface Noisy {
void makeNoise();
}
interface Vehicle {
void go(int distance);
}
class Truck implements Vehicle {
...
}
class Siren implements Noisy {
...
}
class Ambulance extends Truck implements Noisy {
private Siren siren = new Siren();
public makeNoise() {
siren.makeNoise();
}
...
}
Java中不允许多继承,方法如下:
public interface AInterface {
public void a();
}
public interface BInterface {
public void b();
}
public class A implements AInterface {
public void a() {}
}
public class B implements BInterface {
public void b() {}
}
public class C implements AInterface, BInterface {
private A a;
private B b;
public void a() {
a.a();
}
public void b() {
b.b();
}
}