Question

In the following contrived example, data is given a warning due to it being unused. Can someone explained why this is something to warn about?

public abstract class Worker {

    private Object data;

    public Worker(Object data) {
        this.data = data;
    }

    public abstract Result run();

}

The point of course, is that the data object is used, just not in this abstract class. What should I be doing to make this error go away, ie is it an eclipse setting, or am I just doing something wrong.

Answer 1

The point of course, is that the data object is used, just not in this abstract class.

How? It’s private. The subclasses won’t be able to see it, unless they’re using reflection.

You could make it protected so that subclasses can see it – or better (IMO), provide a protected getData() method.