java-stream

There is a collection ArrayList that stores objects of the Student(<HashMap<Subject, Integer> rating, String name> ... tNameFaculty() + " in the subject " + subject + " average mark " + averageMarkOnSomeSubjectOnFaculty); }

You need to write a program to count the number of occurrences of each word in the file using the stream api.

If the thread was created locally, is it necessary to close it at the end of the method? public void method() { FileInputStream fis = new FileInputStream("input.txt"); ... fis.close(); //Необходимо ли это? }

There is a function: <R> Stream<R> map(Function<? super T, ? extends R> mapper); It performs operations ... fter all, we just pass the implementation with specific T(User) and R(String), where can we use subclasses and superclasses?

Tell me how to convert: Map<String, List<Pet>> pets = petList .stream() .collect(Collect ... s? PetHouse - it's just a kind of wrapper over the sheet List<Pet> petList; PetHouse house = new PetHouse(petList);

How can I convert console input System.in in a Stream of characters. I tried this combination: new BufferedReader(new Input ... r(Character::isDigit) .map(Character::getNumericValue) .limit(3) .toArray();

Need a function that calculates the min and max from Stream public static <T> void findMinMax( Stream<? ... right away, because the passed parameter Stream<? extends T> stream is not only Integer maybe, how to fix this problem?

There is a certain string(for example, "Some example"). You need to determine the number of occurrences of each letter in a s ... et.putAll(toCharMap(it)); return ret; } But now how to count them in the stream, for example, using filter and reduce?

How to debug Java 8 streams in Intelij IDEA? All intermediate calls are lazy and are executed during a terminal operation, so ... e step other than the start and end. System.out. println arrange-somehow unprofessional, are there other ways out of the box?

Let there be IntStream, is it possible to get from it a valid array or sheet, in which there will be 2 values min and max of the stream? Or is it even possible to somehow call the terminal method on the stream more than 1 time?

I have the following code. Explain why in the first call to the map() method, IDEA highlights it and suggests replacing it wi ... el.getValue() + "\"}"; el.setValue(sb); return el; }).map(Map.Entry::getValue).collect(Collectors.toList());

Which of the following is the best practice in Java 8? Java 8: list.forEach(e -> e.operation); Java 7: for (E e : lis ... bdas, but are there any real benefits from using Iterator.foreach? Will the performance and readability of the code improve?

I don't really understand the difference between findFirst() and findAny() in the Java Stream API. I thought that findFirst ... and Stream.of(...).findAny() Then they both return the first element of the stream. Why? Are they both doing the same task?

What is the difference between the methods Stream.map and Stream.flatMap apart from each other?

This question is already answered here: ... , in streams, sometimes in lambda expressions. What does it mean? What does List :: stream mean? P.S. And what is it called?

I have minSdkVersion == 21 Previously, when I tried to use stream, I got an error - you can't, available from version 24. In ... where? Or Android-studio just blunted show error and on versions below 24 I will get crashes(I don't have a device to check)?