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> names = Arrays.asList("Bob", "Tom", "Jeff", "Scott", "Jennifer", "Steve");

    Optional<String> firstS = names.stream().filter(name -> name.startsWith("S")).findFirst();
    System.out.println(firstS.orElse("None found"));

    Optional<String> firstZ = names.stream().filter(name -> name.startsWith("Z")).findFirst();
    if (firstZ.isPresent()) {
        System.out.println(firstZ.get());
    } else {//  w  ww  . ja v a  2 s  . co m
        System.out.println("No Z's found");
    }
}

From source file:Main.java

public static void main(String[] args) {
    List<Person> roster = createRoster();
    roster.stream().forEach(p -> p.printPerson());

}

From source file:Main.java

public static void main(String[] args) {

    List<String> names = Arrays.asList("CSS", "CSS3", "HTML", "Java", "Javascript", "Oracle", "MySQL");

    String name5 = names.stream().map(Main::toUpperCase).filter(Main::greaterThanFive).limit(2)
            .collect(Collectors.joining(" + ")).toString() + " = WSM!!!";

    System.out.println(name5);/*from w w w  .  j av  a2  s.c  om*/
}

From source file:Main.java

public static void main(String[] args) {
    List<Person> persons = Arrays.asList(new Person("FooBar", 12), new Person("BarFoo", 16));
    Stream<Integer> stream = persons.stream().map(x -> x.getAge());
    int sum = stream.reduce(0, (l, r) -> l + r);
    System.out.println(sum);//  w ww. ja  v a  2 s  . com
}

From source file:Main.java

public static void main(String[] argv) throws Exception {
    List<String> argList = Arrays.asList("help", "v");

    Predicate<String> isHelp = (s) -> s.matches("(h|help)");

    argList = argList.stream().filter(isHelp.negate()).collect(Collectors.toList());

    System.out.println(argList);/* w ww.  j  a  va  2 s. c  om*/
}

From source file:Main.java

public static void main(String[] args) {
    List<Employee> persons = Employee.persons();

    persons.stream().filter(Employee::isFemale).forEach(p -> p.setIncome(p.getIncome() * 1.10));

    System.out.println("After increasing the income: " + persons);
}

From source file:Main.java

public static void main(String[] args) {
    List<String> names = Arrays.asList("XML", "HTML", "CSS", "Javascript", "Java", "Static");

    Optional<String> longestName = names.stream()
            .reduce((name1, name2) -> name1.length() >= name2.length() ? name1 : name2);

    if (longestName.isPresent()) {
        System.out.println(longestName.get());
    } else {//from   w w w . java  2  s .  c  om
        System.out.println("WTF?");
    }

}

From source file:Main.java

public static void main(String[] args) {
    List<Trade> trades = TradeUtil.createTrades();
    trades.stream().filter(t -> t.getIssuer().equals("IBM")).forEach(System.out::println);

    System.out.println();//  ww  w . java 2 s  . co  m
    trades.stream().filter(t -> t.getIssuer().equals("IBM")).filter(t -> t.getQuantity() > 15)
            .forEach(x -> System.out.println("IBM trades, qty over 15 " + x));

    System.out.println();
    Consumer<Trade> printTrade = x -> System.out.println(x);
    trades.stream().filter(t -> t.getIssuer().equals("IBM")).filter(t -> t.getQuantity() > 15)
            .filter(t -> t.getStatus().equals("NEW")).forEach(printTrade);
}

From source file:Main.java

public static void main(String args[]) {
    List<Person> people = Arrays.asList(new Person("B", 25, "Main Street"), new Person("A", 27, "Off Street"));
    List<String> listNames = people.stream().map(u -> u.getName()).collect(Collectors.toList());
    System.out.println(listNames);
}

From source file:Main.java

public static void main(String[] args) {
    List<Employee> persons = Employee.persons();

    Employee[] men = persons.stream().filter(p -> p.getGender() == Gender.MALE).toArray(Employee[]::new);

    System.out.println("After increasing the income: " + men);
}