import java.util.List;
import java.util.ArrayList;
public class DataProcessor {
private List items;
public DataProcessor() {
this.items = new ArrayList<>();
}
public void addItem(String item) {
items.add(item);
}
public List process() {
return validate(items);
}
private List validate(List data) {
List result = new ArrayList<>();
for (String s : data) {
if (s != null && !s.isEmpty()) {
result.add(s.trim());
}
}
return result;
}
}
interface Processor {
List process();
}