How to implement an interface in a different OSGi bundle?

Question

I have literally just started and I think this is such a basic question that I can't even find anything online about it but I can't for the life of me figure this out.

I have two seperate bundles, one an API and one a Service bundle. In a package in the API bundle I have an interface called "HelloAPI":

package com.example.osgi.api;

public interface HelloAPI {

    public void sayHello();

}

In the service bundle I have a class with the following code:

package com.example.osgi.service;

public class HelloImpl {

    implements HelloAPI {
        System.out.println("Hello World!");
    }
}

but eclipse has highlighted an error under the "implements" keyword which is:

Syntax error on token "implements", interface expected.

I can't see what I've done wrong, can anyone point me in the right direction? Thanks.

Answer 1

I strongly agree with the comments — it's vital to learn the fundamentals of the Java language before tackling more advanced topics like modularity.

For reference, here is a correct implementation of your interface:

public class HelloImpl implements HelloAPI {
    public void sayHello() {
        System.out.println("Hello World!");
    }
}