Search results for: Open API
Parallel Streams – How does it work?
class Test { public static void main(String[] args) { System.out.println(Runtime.getRuntime().availableProcessors()); } } IntStream.rangeClosed(1, 100000) .parallel() .sum();
Read More Parallel Streams – How does it work?Parallel Streams Performance Testing
private static void sumWithRegularStream() { for (int i = 0; i < 10; i++) { IntStream.rangeClosed(1, 100000).sum(); } } private static void sumWithParallelStream() { for (int i = 0; i < 10; i++) { IntStream.rangeClosed(1, 100000).parallel().sum(); } } class Test { public static void main(String[] args) { long regularStreamStartTime = System.currentTimeMillis(); sumWithRegularStream(); System.out.println(“Regular Stream execution…
Read More Parallel Streams Performance TestingSpring Cloud Config Server and Config Client
This tutorial will teach you how to create your own Spring Cloud Config Server and how to configure a Spring Boot Application to be a Spring Cloud Config Client. Spring Cloud Config Server Spring Cloud Config Server is a Spring Boot application. So to create our own Spring Cloud Config Server, we must first create…
Read More Spring Cloud Config Server and Config ClientOptional – filter() operation
public Optional<T> filter(Predicale<T> predicate) class Test { public static void main(String[] args) { Optional<String> stringOptional = Optional.ofNullable(“alegru coding”); stringOptional.filter(str -> str.length() > 10) .map(String::toUpperCase) .ifPresent(System.out::println); } } Output: ALEGRU CODING class Test { public static void main(String[] args) { Optional<User> userOptional = Optional.ofNullable(new User(“John”, “john123”, “premium”, “5th Avenue”)); userOptional.filter(user -> user.getMembershipType().equals(“premium”)) .ifPresent(System.out::println); } } class…
Read More Optional – filter() operationStreams – groupingBy() operation
public static <T, K> Collector<T, ?, Map<K, List<T>>> groupingBy(Function<? super T, ? extends K> classifier) class Test { public static void main(String[] args) { List<String> cities = new ArrayList<>(Arrays.asList(“Paris”, “Bern”, “London”, “Tokyo”, “Boston”)); Map<Integer, List<String>> resultMap = cities.stream() .collect(Collectors.groupingBy(String::length)); System.out.println(resultMap); } } Output: {4=[Bern], 5=[Paris, Tokyo], 6=[London, Boston]} class Test { public static void main(String[]…
Read More Streams – groupingBy() operationStreams – collect() operation
class Test { public static void main(String[] args) { List<String> words = new ArrayList<>(Arrays.asList(“Hello”, “World”, “of”, “Java!”)); String result = words.stream().collect(Collectors.joining()); System.out.println(result); String resultWithDelimiters = words.stream().collect(Collectors.joining(“-“)); // delimiter System.out.println(resultWithDelimiters); String resultWithDelimitersAndPrefixAndSuffix = words.stream().collect(Collectors.joining(“-“, “(“, “)”)); // delimiter, prefix, suffix System.out.println(resultWithDelimitersAndPrefixAndSuffix); } } Output: HelloWorldofJava! Hello-World-of-Java! (Hello-World-of-Java!) class Test { public static void main(String[] args) {…
Read More Streams – collect() operationStreams – DoubleStream class
DoubleStream.of(2.4); DoubleStream.of(7.1, 10.5, 12.7); DoubleStream.iterate(0, i -> i + 2).limit(10); DoubleStream.generate(() -> Math.random() * 5).limit(10); class Test { public static void main(String[] args) { DoubleStream doubleStream = DoubleStream.of(1.2, 3.1, 7.2, 5.3, 9.8); doubleStream.forEach(item -> System.out.print(item + ” “)); } } Output: 1.2 3.1 7.2 5.3 9.8 class Test { public static void main(String[] args) {…
Read More Streams – DoubleStream classStreams – LongStream class
LongStream.of(7); LongStream.of(7, 8, 9); LongStream.range(1, 3); LongStream.rangeClosed(1, 3); LongStream.iterate(0, i -> i + 2).limit(10); LongStream.generate(() -> (long) (Math.random() * 5)).limit(10); class Test { public static void main(String[] args) { LongStream longStream = LongStream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); longStream.forEach(item -> System.out.print(item + ” “)); } } Output: 1 2 3 4…
Read More Streams – LongStream classStreams – IntStream class
IntStream.of(5); IntStream.of(1, 2, 3); IntStream.range(1, 3); IntStream.rangeClosed(1, 3); IntStream.iterate(0, i -> i + 2).limit(10); IntStream.generate(() -> (int) (Math.random() * 5)).limit(10); class Test { public static void main(String[] args) { IntStream intStream = IntStream.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10); intStream.forEach(item -> System.out.print(item + ” “)); } } Output: 1 2 3 4…
Read More Streams – IntStream classStreams – findAny() operation
Optional<T> findAny() class Test { public static void main(String[] args) { List<Integer> numbers = new ArrayList<>(Arrays.asList(3, 7, 9, 15, 17)); Optional<Integer> resultOptional = numbers.stream().findAny(); if (resultOptional.isPresent()) { // checking if optional contains any value System.out.println(“The element returned from the stream: ” + resultOptional.get()); // getting the value from Optional } else { System.out.println(“The stream is…
Read More Streams – findAny() operationStreams – reduce() operation
T reduce(T identity, BinaryOperator<T> accumulator); class Test { public static void main(String[] args) { List<Integer> numbers = new ArrayList<>(Arrays.asList(3, 5, 7, 9)); int result = numbers.stream() .reduce(1, (num1, num2) -> num1 * num2); System.out.println(“The result is: ” + result); } } Output: The result is: 945 class Test { public static void main(String[] args) {…
Read More Streams – reduce() operationStreams – noneMatch() operation
boolean noneMatch(Predicate<? super T> predicate) class Test { public static void main(String[] args) { List<Integer> numbers = new ArrayList<>(Arrays.asList(12, 17, 20, 8, 92, 15, 9, 31, 7)); System.out.println(numbers.stream() .noneMatch(number -> number < 5)); } } Output: true class Test { public static void main(String[] args) { System.out.println(getStudents().stream() .noneMatch(student -> student.getGrade() < 7)); } private static…
Read More Streams – noneMatch() operationStreams – anyMatch() operation
boolean anyMatch(Predicate<? super T> predicate) class Test { public static void main(String[] args) { List<Integer> numbers = new ArrayList<>(Arrays.asList(20, 12, 12, 8, 9, 5, 32, 19)); System.out.println(numbers.stream() .anyMatch(number -> number > 25)); } } Output: true class Test { public static void main(String[] args) { System.out.println(getStudents().stream() .anyMatch(student -> student.getGrade() > 8)); } private static List<Student>…
Read More Streams – anyMatch() operationStreams – allMatch() operation
boolean allMatch(Predicate<? super T> predicate) class Test { public static void main(String[] args) { List<Integer> numbers = new ArrayList<>(Arrays.asList(2, 4, 6, 8, 10, 12, 14, 16, 18, 20)); System.out.println(numbers.stream() .allMatch(number -> number % 2 == 0)); } } Output: true class Test { public static void main(String[] args) { boolean areAllPremiumMembers = getAllUsers().stream() .allMatch(user ->…
Read More Streams – allMatch() operation