Logging the result of filter while using java streams filter by predicate

Question

The scenario is there are different types of filters I have created which filters the list of some objects based on the property of the object.

So for that I have

Answer 1

You can simply add brackets to your lambda expression and add the logging statement right before the validation :

return event -> {
    // LOG.info(event.getName() + " was filtered...") or whatever you use for logging.
    return event.getPrizeCount() >= minimumNumOfPrizes;
}

Note that there exists a peek operation which is meant to be used mostly for logging on java streams :

events.stream()
      .peek(event -> System.out.println("Filtering event" + event.getName()))
      .filter(isEligible())
      .collect(Collectors.toList());

but that is not helping here, as you need to log in AbstractEventFilter implementations.