Question

I am using eclipse , when I use shortcut to generate override implementations , there is an override annotation up there , I am using JDK 6 , this is all right , but under JDK 5 this annotation will cause an error, so I want to ask , if this annotation is completely useless ? Will compiler do some kind of optimization using this annotation ?

Answer 1

As others have pointed out, the @Override annotation is really a compiler directive that instructs javac to scream if a method annotated with @Override does not actually override a method in its parent class (e.g. you’re actually overloading because you’ve decided to change the method signature or you misspell the method name).

Under JDK 5, directly implementing a method from an interface is not considered overriding that method and is considered an error if annotated with @Override.

In part due to user feedback that this was a really confusing behaviour, JDK 6 changed this behaviour and does consider it correct to annotate a method you implement from an interface with @Override.