java - 我如何才能知道此 Java API 更改发生的时间？

Question

在某些时候，java.lang.Override 开始可用于实现接口(interface)中声明的方法。我很确定曾经有一段时间它只适用于覆盖父类(super class)中定义的方法。

我如何才能知道此更改发生的时间(即在哪个版本)？

Answer 1

在从接口(interface)实现但未从父类(super class)覆盖的方法上使用@Override 注释是Java 6 中的一项新功能。参见@Override specification changes in Java 6。 :

Between Java 5 and Java 6 changes to the specification of @Override have been made. In Java 6 it is possible to add the @Override annotation to methods that implement methods of an interface which is not allowed in Java 5.

I noticed the difference when a friend told me that he had to remove all the @Override annotations to make his Java 6 project compile with Java 5.

The interesting thing is that there is no documentation about this change. The API specification of @Override is exactly the same in both Java versions. I found out that this was forgotten by Sun developers. Peter Ahé, a former developer at Sun, calls it the @Override Snafu.