Example usage for java.util List stream

Introduction

In this page you can find the example usage for java.util List stream.

Prototype

default Stream<E> stream()

Source Link

Document

Returns a sequential Stream with this collection as its source.

Usage

From source file:Main.java

public static void main(String[] args) {
    List<String> stringList = Arrays.asList("1.2", "2.2", "3", "4", "5");

    stringList.stream().flatMapToLong(n -> LongStream.of(Long.parseLong(n))).forEach(System.out::println);
}

From source file:Main.java

public static void main(String[] args) {
    List<String> stringList = Arrays.asList("1.2", "2.2", "3", "4", "5");

    stringList.stream().mapToDouble(n -> Double.parseDouble(n)).filter(n -> n % 2 == 0)
            .forEach(System.out::println);
}

From source file:Main.java

public static void main(String[] args) {
    List<String> stringList = Arrays.asList("1.2", "2.2", "3", "4", "5");

    stringList.stream().flatMapToDouble(n -> DoubleStream.of(Double.parseDouble(n)))
            .forEach(System.out::println);
}

From source file:Main.java

public static void main(String[] args) {
    List<String> stringList = Arrays.asList("2", "1", "3", "4");

    long m = stringList.stream().collect(Collectors.counting());
    System.out.println(m);//from   ww  w.  jav a 2 s.  c o  m
}

From source file:Main.java

public static void main(String[] args) {
    List<String> stringList = Arrays.asList("2", "1", "3", "4");

    Object[] n = stringList.stream().toArray();
    System.out.println(Arrays.toString(n));
}

From source file:Main.java

public static void main(String[] args) {

    List<Integer> l = Arrays.asList(4, 3, 5, 7, 2, 2, 3, 5);

    l.stream().reduce((a, b) -> a + b).ifPresent(System.out::println);

    l.parallelStream().reduce((a, b) -> a + b).ifPresent(System.out::println);

    System.out.println("isParallel list.stream(): " + l.stream().isParallel());

    System.out.println("isParallel list.stream().parallel(): " + l.stream().parallel().isParallel());

    System.out.println("isParallel list.parallelStream(): " + l.parallelStream().isParallel());

    System.out.println(//w  w  w  . j av a 2s .  c o m
            "isParallel list.parallelStream().sequential(): " + l.parallelStream().sequential().isParallel());
}

From source file:Main.java

public static void main(String... args) {
    List<Integer> numbers = Arrays.asList(3, 4, 5, 1, 2);

    Optional<Integer> min = numbers.stream().reduce(Integer::min);
    min.ifPresent(System.out::println);

}

From source file:Main.java

public static void main(String[] args) {
    List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
    Optional<Integer> o = numbers.stream().findAny();
    if (o.isPresent()) {
        System.out.println(o.get());
    } else {//from w  ww .ja  va2 s . co m
        System.out.println("no value");
    }

}

From source file:Main.java

public static void main(String[] args) {
    List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
    Optional<Integer> o = numbers.stream().findFirst();
    if (o.isPresent()) {
        System.out.println(o.get());
    } else {/* w ww .j  a v a2  s . co m*/
        System.out.println("no value");
    }

}

From source file:Main.java

public static void main(String[] args) throws Exception {
    // map//w w w  . ja  v a  2s. c  om
    List<String> words = Arrays.asList("Hello", "World");
    List<Integer> wordLengths = words.stream().map(String::length).collect(Collectors.toList());
    System.out.println(wordLengths);

}