java - Java中的隐式 super 接口(interface)？

Question

所以我们都知道所有的类都隐式扩展了Object。接口(interface)怎么样？是否有隐式 super 接口(interface)？我说有。编译以下代码:

java.io.Serializable s1 = null;
java.io.Serializable s2 = null;

s1.equals(s2);

equals 方法不是在 Serializable 中声明的，而是在 Object 中声明的。由于接口(interface)只能扩展其他接口(interface)，而 Object 是一个类，而不是接口(interface)，因此必须有一些隐式接口(interface)正在被扩展。然后 Object 类必须隐式实现这个隐式接口(interface)(哇，写起来很奇怪)。

那么，问题是，这有多正确？

Answer 1

Since interfaces can only extend other interfaces, and Object is a class, not an interface, there must be some implicit interface that is being extended.

没有。引用 Java Language Specification :

If an interface has no direct superinterfaces, then the interface implicitly declares a public abstract member method m with signature s, return type r, and throws clause t corresponding to each public instance method m with signature s, return type r, and throws clause t declared in Object, unless a method with the same signature, same return type, and a compatible throws clause is explicitly declared by the interface. It is a compile-time error if the interface explicitly declares such a method m in the case where m is declared to be final in Object.

这与您的“隐式 super 接口(interface)”之间的区别在于 Object 有许多最终和 protected 方法，您不能在接口(interface)中使用这些修饰符。