get the last non null object from List of objects [duplicate]

You solved 80%: first collect and filter. This will give a new collection using Java 8 streams.

Literally: last

Then pick the last from the filtered collection, e.g. on list using list.get(lastIndex) where int lastIndex = list.size()-1 .

The last is a bit ambiguous, so I have 2 approaches 😉️

List<Person> personList = getAllPersons(); // typo: name of List should be plural e.g. `personActiveList` or `activePersons` List<Person> personActive = personList.stream() .filter(person -> person.getPersonStatus()!=null) .toList(); // the last in order of appearance Person lastInActiveList = personActice.get(personActice.size()-1); // may throw NPE if list empty // the last who was active by some Instant timestamp List<Person> sortByLastActive = personList.stream() .filter(person -> person.getPersonStatus()!=null) .sorted(Person::getTimestamp()) # sort by Instant property .toList(); Person lastRecentlyActice = sortByLastActive.get(sortByLastActive.size()-1); // may throw NPE if list empty 

Note: For brevity I used toList() as terminator (since Java 16).

You could also use collect(Collectors.toList()) from older Java versions. Beware: Differences of Java 16's Stream.toList() and Stream.collect(Collectors.toList())?

⚠️ Caution: all random get operations on list can throw a NullPointerException (NPE) if the list is empty. This should be tested using if (list.isEmpty()) before to prevent illegal access.

Trick: reverse to first

The trick here as commented by Boris is to reverse the list before opening the stream, thus before it becomes filtered/collected as result. Afterwards you can directly pick the first.

List<Person> personActiveReversed = Collections.reverse(personList).stream() // reverse to get last elements first .filter(person -> person.getPersonStatus()!=null) .toList(); // may throw NPE if list empty Person last = personActiveReversed.get(0); // safer: directly on stream Optional<Person> last = Collections.reverse(personList).stream() // reverse before streaming .filter(person -> person.getPersonStatus()!=null) .findFirst(); // originally the last or empty // evaluate optional if (last.isPresent()) { System.out.println("found the last: " + last.get()); } else { System.out.println("nobody found at last :("); } 

Explained:

• see comments by Boris below and on question: use Collections.reverse before .stream to reverse an ordered list (from last to first). Then reversedList.get(0) will get the originally last element.

• findFirst() is the new terminator, returning Java 8 type-wrapper Optional. This is null-safe but requires a further test or convenience-methods like orElse(defaultObject), e.g. last.orElse(null).

See also

• collections - comparing Instants in Java8 - Stack Overflow
• How to use Comparator in Java to sort, 🎉 comparing a peopleList
• Java 8 stream reverse order, contains answer 'How NOT to do it': e.g. don't use ⚠️ lambda (a, b) -> -1 to reverse the elements in stream (swapping). It violates Comparator contract and might break depending on underlying implementation.
• How to get ordered stream from a list in reverse order in Java 8, interesting discussion on generic list sorting
• How to Get the Last Element of a Stream in Java? | Baeldung, alternatives using skip or reduce with warning note on stream types

int lastNotNull = -1; for(int i = 0; i < personList.size();i++){ if(person.getPersonStatus()!=null) lastNotNull = i; } 

lastNotNull is the index of the last not null Person