http://journal.stuffwithstuff.com/2012/12/19/the-impoliteness-of-overriding-methods/

ItemProcessor.java

public ItemProcessor extends IterativeProcessor<String> implements Processor {
    
    @Override
    public List<String> getItems(Request req) {
        return req.getParameters("items");
    }
    
    @Override
    public void processItem(Request req, String item) {
        Database.saveItem(item);
    }
}

IterativeProcessor.java

public abstract IterativeProcessor<T> implements Processor {

    protected abstract List<T> getItems(Request req);

    protected abstract void processItem(Request req, T item);

    @Override
    public final void process(Request req) {
        for (T item : getItems(req)) {
            processItem(req, item);
        }
    }
}

Processor.java

public interface Processor {

    public void process(Request req);
}