java-stream Questions
6
Solved
How can I split odd and even numbers and sum both in a collection using stream methods of Java 8?
public class SplitAndSumOddEven {
public static void main(String[] args) {
// Read the input
t...
Cleancut asked 22/1, 2016 at 5:10
9
Solved
I have read a lot about Java 8 streams lately, and several articles about lazy loading with Java 8 streams specifically: here and over here. I can't seem to shake the feeling that lazy loading is C...
Angioma asked 7/10, 2018 at 4:46
15
My exact scenario is inserting data to database in batches, so I want to accumulate DOM objects then every 1000, flush them.
I implemented it by putting code in the accumulator to detect fullness ...
Edam asked 20/12, 2014 at 19:33
7
Solved
In java 8, what's the best way to check if a List contains any duplicate?
My idea was something like:
list.size() != list.stream().distinct().count()
Is it the best way?
Stonemason asked 5/5, 2015 at 12:50
6
Solved
I have the following expression:
scheduleIntervalContainers.stream()
.filter(sic -> ((ScheduleIntervalContainer) sic).getStartTime() != ((ScheduleIntervalContainer)sic).getEndTime())
.collect...
Hearsh asked 2/3, 2016 at 7:3
8
Solved
Is there a concise way to extract both the min and max value of a stream (based on some comparator) in one pass?
There appear to be many ways to get the min and max values individually, or I can s...
Engrain asked 23/1, 2017 at 21:46
7
Solved
My colleague and I had a bug that was due to our assumption that an empty stream calling allMatch() would return false.
if (myItems.allMatch(i -> i.isValid()) {
//do something
}
Of course,...
Merocrine asked 13/5, 2015 at 18:53
5
Solved
I have the following code which could be much simpler using Java 8 stream API:
List<List<String>> listOfListValues;
public List<String> getAsFlattenedList() {
List<String>...
Fawnfawna asked 28/11, 2018 at 9:3
6
Solved
I want to implement a Stream<T>.
I don't want to just use implements Stream<T>, because I would have to implement a ton of methods.
Can this be avoided?
To be more concrete, how can ...
Biggers asked 6/6, 2015 at 17:27
5
Solved
Does someone know how I would write a sequence processing in a java stream API manner in Python ? The idea is to write the operations in the order they will happen:
myList.stream()
.filter(conditi...
Homologize asked 10/2, 2019 at 15:38
6
Solved
Why does this throw a java.lang.NullPointerException?
List<String> strings = new ArrayList<>();
strings.add(null);
strings.add("test");
String firstString = strings.stream()
...
Multiplicity asked 8/9, 2015 at 20:36
5
Solved
Such as in .Net, which provides several implementations of the Action delegate (equivalent to Java Consumer functional interface) with different number and type of arguments, I was expecting that J...
Jewelry asked 16/7, 2014 at 11:8
11
Solved
I have a list of Integer list and from the list.stream() I want the maximum value.
What is the simplest way? Do I need comparator?
Gyrostat asked 13/7, 2015 at 8:10
14
Solved
Collectors.toMap throws a NullPointerException if one of the values is null. I don't understand this behaviour, maps can contain null pointers as value without any problems. Is there a good reason ...
Khelat asked 8/7, 2014 at 11:44
4
Solved
Suppose we have two streams as follows:
IntStream stream1 = Arrays.stream(new int[] {13, 1, 3, 5, 7, 9});
IntStream stream2 = Arrays.stream(new int[] {1, 2, 6, 14, 8, 10, 12});
stream1.merge(stream...
Selfish asked 30/9, 2018 at 4:0
7
Solved
How do I sort string values in case-insensitive order in the following?
List<Employee> listofEmployees = Arrays.asList(
new Employee(1, "aaa", Arrays.asList(123, 345, 678)),
new Employee(1...
Permeate asked 13/4, 2018 at 16:50
12
Solved
How to implement "partition" operation on Java 8 Stream? By partition I mean, divide a stream into sub-streams of a given size. Somehow it will be identical to Guava Iterators.partition()...
Careen asked 7/9, 2015 at 8:50
10
Solved
Suppose I have a method that returns a read-only view into a member list:
class Team {
private List<Player> players = new ArrayList<>();
// ...
public List<Player> getPlayers...
Eberhardt asked 10/7, 2014 at 12:42
5
Solved
I have a Stream<Set<Integer>> intSetStream.
I can do this on it...
Set<Integer> theSetWithTheMax = intSetStream.max( (x,y)->{ return Integer.compare( x.size(), y.size() ); } ...
Mommy asked 11/4, 2018 at 19:6
4
Solved
I am getting
Cannot infer type arguments for java.util.HashMap<>
for the following code
class Test {
public static void main(String[] args) {
Map<Integer, String> map = new Ha...
Algebraist asked 23/11, 2017 at 7:17
2
Solved
I have a list of orders and I want to group them by user using Java 8 stream and Collectors.groupingBy:
orderList.stream().collect(Collectors.groupingBy(order -> order.getUser())
This return ...
Rundlet asked 14/6, 2016 at 14:57
35
Solved
In Java 8 how can I filter a collection using the Stream API by checking the distinctness of a property of each object?
For example I have a list of Person object and I want to remove people with ...
Amaris asked 16/5, 2014 at 15:40
7
Solved
Is it possible to cast a stream in Java 8? Say I have a list of objects, I can do something like this to filter out all the additional objects:
Stream.of(objects).filter(c -> c instanceof Clien...
Contrite asked 19/3, 2014 at 16:9
6
I have a List of Integer say list1, and I want to get another list list2 which will contain the cumulative sum up until the current index from start. How can I do this using Stream API java 8 ?
Li...
Nardone asked 20/3, 2019 at 16:32
4
I have a problem which I feel would be perfect for streams and/or lambdas. On the other hand I don't want to overcomplicate this, but since will use this specific technique in many variations (run ...
Cutch asked 3/4, 2017 at 19:2
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