在java中创建接口对象 [英] Creating interface objects in java

问题描述

我遇到了一些Java代码：

I encountered some Java code:

public class LocationProvider {

   public interface LocationCallback {
      public void handleNewLocation(Location location);
   }

   // class constructor
   public LocationProvider(Context context, LocationCallback callback){ 
      ...
   }
}

我第一次遇到一个带有类型参数的构造函数或方法是一个界面。是否可以创建接口对象？你可以像常规对象一样使用它们吗？

For the first time in Java, I am encountering a constructor or method with an argument of a "type" that is an interface. Is it possible to create objects of interfaces ? Can you use them like regular objects ?

在C ++中我知道不可能创建抽象类的对象。

In C++ I know it's not possible to create objects of an abstract class.

推荐答案

好的。让我们来看看基础：）。

Ok. Lets go over the basics :).

class A implements X{// where X is an interface
}

class B implements X{
}

现在，我们有

void someMethodAcceptingInterfaceX(X someInstanceOfX)
{
//do something
}

现在你可以做，

X a = new A();
X b = new B();
someMethodAcceptingInterfaceX(a);
someMethodAcceptingInterfaceX(b);

即，您可以传递任何接口X 。实现接口的任何类都被称为接口的实例（在更广泛的上下文中）。

i.e, you can pass anything which is interface X. Any class which implements an interface is said to be an instance of that interface (in a broader context).

这篇关于在java中创建接口对象的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！