Eclipse: always notice error when use @Override

Question

I don't know why each time I implements a class. when I use @Override Eclipse always notice error:

the method A of type B must override a superclass method

(With method A is method that I override and B is the current class I work with)

And Eclipse recommend delete @Override

But with the same code, I work on Idea, no error found.

Who can tell me why,please.

thanks :)

@Edit: Oh, I don't post exactly code because It happend for all when I implement sth: for example:

public class helloworld implements Runnable {
    @Override //this line no-error with Idea and error with eclipse:the method run of type helloworld must be override a super class
    public void run(){
    }

I second Oscar's advice -- which should be obvious, no? It's like you're asking us to read your mind and guess the code that's causing the error. — Hovercraft Full Of Eels, Feb 09 '12 at 03:39
class A inherits from class B and override a method of class B? publishes the code — Jhonathan, Feb 09 '12 at 03:42
What JDK compliance is your Eclipse Java compiler set to? I think that override annotations were not allowed for interface methods in some earlier versions of Java. — Hovercraft Full Of Eels, Feb 09 '12 at 03:51
I'm using JDK 7. And at least, JDK version same with Eclipse and Idea — hqt, Feb 09 '12 at 03:54
@hqt: and I have asked another question. Again, what jdk compliance is your Eclipse Java compiler set to? You check by going to the Windows -- Preferences -- Java -- Compiler menu. And no, I'm not asking your Java *version* but your Eclipse setting on JDK *compliance*! There's a big difference! — Hovercraft Full Of Eels, Feb 09 '12 at 03:54
Would JDK compliance level really affect something as fundamental as an @override annotation? I bet the OP's eclipse is simply in a bad state and needs to be restarted. I've seen this happen before. A "refresh" on the source tree or a restart fixes all these bogus errors that show up. — eternaln00b, Feb 09 '12 at 04:00
@SiddharthaShankar Actually yes, I had exactly this issue come up a couple of times very recently, and that was the fix. — Jeff, Feb 09 '12 at 04:04
@Jeff, changing the compliance level was the fix, or was it restarting Eclipse? — eternaln00b, Feb 09 '12 at 04:05
ah, I see. With some searching, I find that the @override annotation was a relatively recent introduction. Hmmm... It would be nice if people posted the rationale for their suggestions for some of us less enlightened folks. :) — eternaln00b, Feb 09 '12 at 04:08
@SiddharthaShankar Actually you might just need to read a little closer: From Hovercraft Full Of Eels comment: `I think that override annotations were not allowed for interface methods in some earlier versions of Java.` — Jeff, Feb 09 '12 at 04:12
@Jeff, my mistake again! I read his later comment, but not the earlier one. Apologies all round. — eternaln00b, Feb 09 '12 at 04:14
Oh, thanks. I have fixed my problem (thanks to Hovercraft Full Of eels). Here is his post: (I post again for overall answer) Again, what jdk compliance is your Eclipse Java compiler set to? You check by going to the Windows -- Preferences -- Java -- Compiler menu. And no, I'm not asking your Java version but your Eclipse setting on JDK compliance! — hqt, Feb 09 '12 at 05:16
Go to windows-> preferences -> Java -> compiler -> Select compiler compliance level to 1.6(which version you want)-> Apply-> ok. now its work. — madhu, Dec 30 '14 at 14:17

score 8 · Accepted Answer · answered Feb 09 '12 at 04:38

8

Java 5 only properly supports this annotation on methods you override when subclassing. Starting with Java 6 you can also use this annotation on methods that implement methods from an interface.

answered Feb 09 '12 at 04:38

Vadim

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score 5 · Answer 2 · answered Feb 09 '12 at 04:20

5

Check your compliance setting. It should be JDK 6+

answered Feb 09 '12 at 04:20

manocha_ak

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score 2 · Answer 3 · answered Feb 09 '12 at 04:06

2

It's a java version issue. In one IDE you are using JDK 6/7 which allow this. In another you are using Java 5, which did not.

answered Feb 09 '12 at 04:06

MJB

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Eclipse: always notice error when use @Override

3 Answers3