Why Does Eclipse Complain About @Override on Interface Methods

Why does Eclipse complain about @Override on interface methods?

Using the @Override annotation on methods that implement those declared by an interface is only valid from Java 6 onward. It's an error in Java 5.

Make sure that your IDE projects are setup to use a Java 6 JRE, and that the "source compatibility" is set to 1.6 or greater:

1. Open the Window > Preferences dialog
2. Browse to Java > Compiler.
3. There, set the "Compiler compliance level" to 1.6.

Remember that Eclipse can override these global settings for a specific project, so check those too.

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Update:

The error under Java 5 isn't just with Eclipse; using javac directly from the command line will give you the same error. It is not valid Java 5 source code.

However, you can specify the -target 1.5 option to JDK 6's javac, which will produce a Java 5 version class file from the Java 6 source code.

@Override compile error, implementing an interface (eclipse jre7 Windows)

I think have solved it. Earlier I was only modifying the workspace properties only but using maven project with SVN. Maven was internally setting property of each project to use "Project Specific 1.5 java compliance" at each update.

I changed each project to use workspace JDK compliance and removed project specific settings in SVN projects to prevent from future errors after code update.

Thanks.

Why is javac failing on @Override annotation

The @Override annotation spec changed in Java 1.6. In Java 1.5, the compiler did not allow the @Override annotation on implemented interface methods, but in 1.6 it does. First search result I found is a blog post here.. It was not well documented, but it did change.

Eclipse is adding it because your Eclipse is set for 1.6 compliance. You should try to keep your build and eclipse environments on the same version of Java. It's unclear to me by your specifying Cruise Control is running Java 5 on whether or not it is compiling using a separate JDK6 or not.

Separate from the above 1.5 vs 1.6 @Override annotation rules, remember that Eclipse has its own compiler implementation (not javac) and will occasionally have different behavior. Whenever something compiles in Eclipse, but not Ant or Maven, you will need to find a way to make both compilers happy.

Error on @Override annotation with interface implementation

Realized no Builder is selected for current project. Selected Java Builder and boom. No more red flags all over the code.

Add warning for missing @Override annotation for interface implementation in Eclipse

It is not possible in Eclipse 3.4.1. It is a known issue. See this bug report page for more information.

Should we @Override an interface's method implementation?

You should use @Override whenever possible. It prevents simple mistakes from being made. Example:

class C {
    @Override
    public boolean equals(SomeClass obj){
        // code ...
    }
}

This doesn't compile because it doesn't properly override public boolean equals(Object obj).

The same will go for methods that implement an interface (1.6 and above only) or override a Super class's method.

Won't let me override interface method

You are using jdk1.5, switch over to jdk 1.6.

In 1.5 you can't use @override for interface methods while in 1.6 you can. This is the issue you are facing.

@Override on interface methods Eclipse

Make sure there are no project-specific settings that are overriding your defaults. Sometimes, particularly when importing projects, Eclipse will assign a project-specific setting that is less than 1.6.

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