public static void main(String[] args) throws IOException {
Path path = Paths.get("../alice.txt");
String contents = new String(Files.readAllBytes(path), StandardCharsets.UTF_8);
Stream<String> words = Stream.of(contents.split("[\\P{L}]+"));
show("words", words);
Stream<String> song = Stream.of("gently", "down", "the", "stream");
show("song", song);
Stream<String> silence = Stream.empty();
silence = Stream.<String>empty(); // Explicit type specification
show("silence", silence);
Stream<String> echos = Stream.generate(() -> "Echo");
show("echos", echos);
Stream<Double> randoms = Stream.generate(Math::random);
show("randoms", randoms);
Stream<BigInteger> integers = Stream.iterate(BigInteger.ONE, n -> n.add(BigInteger.ONE));
show("integers", integers);
Stream<String> wordsAnotherWay = Pattern.compile("[\\P{L}]+").splitAsStream(contents);
show("wordsAnotherWay", wordsAnotherWay);
try (Stream<String> lines = Files.lines(path, StandardCharsets.UTF_8)) {
show("lines", lines);
}
}
public static void main(String[] args) {
Personne[] tab = {
new Personne("thibault", "Rougier", 2001),
new Personne("thomas", "Niesseron", 1987),
new Personne("thifaine", "Mitenne", 1959),
new Personne("maxime", "Forest", 1995),
new Personne("jules", "Forest", 1995)
};
System.out.println("--- Nes apres 1985 : ");
Stream.of(tab)
.filter(pp -> pp.getAnnee() > 1985)
.forEach(pp -> System.out.print(pp.getPrenom() + ", "));
System.out.println("\n--- Nes avant 2000 :");
long nombre =
Stream.of(tab)
.filter(pp -> pp.getAnnee() < 2000)
.sorted(Comparator.comparing(Personne::getNom))
.peek(pp -> System.out.print(pp.getNom() + " "))
.count();
System.out.println("\n Ils sont " + nombre);
System.out.println("--- Tous tries sur nom + prenom : ");
Stream.of(tab)
.sorted(Comparator.comparing(pp -> pp.getNom() + pp.getPrenom()))
.forEach(pp -> System.out.print("(" + pp.getNom() + ", " + pp.getPrenom() + ") "));
}
public static void main(String... args) {
/*
-------------------------------------------------------------------------
From obj to ...
-------------------------------------------------------------------------
*/
Stream<String> streamOfStrings = Stream.of("un", "deux", "trois");
Function<String, StringBuilder> function = StringBuilder::new;
streamOfStrings.map(function) /*.forEach(System.out::println)*/;
streamOfStrings = Stream.of("un", "deux", "trois");
ToIntFunction<String> toIntFunction = String::length;
IntStream streamOfInts = streamOfStrings.mapToInt(toIntFunction);
streamOfStrings = Stream.of("un", "deux", "trois");
ToDoubleFunction<String> toDoubleFunction = String::length;
DoubleStream streamOfDoubles = streamOfStrings.mapToDouble(toDoubleFunction);
streamOfStrings = Stream.of("un", "deux", "trois");
ToLongFunction<String> toLongFunction = String::length;
LongStream streamOfLongs = streamOfStrings.mapToLong(toLongFunction);
/*
-------------------------------------------------------------------------
From int to ...
-------------------------------------------------------------------------
*/
IntUnaryOperator plusplus = i -> i++;
IntStream.of(1, 2, 3).map(plusplus)
/*.forEach(x->System.out.println(x))*/ ;
IntFunction<String> intFunction = i -> "" + i;
IntStream.of(1, 2, 3).mapToObj(intFunction)
/*.forEach(System.out::println)*/ ;
IntToDoubleFunction itdf = i -> i;
IntStream.of(1, 2, 3).mapToDouble(itdf)
/*.forEach(System.out::println)*/ ;
IntToLongFunction itlf = i -> i;
IntStream.of(1, 2, 3).mapToLong(itlf)
/*.forEach(System.out::println)*/ ;
/*
-------------------------------------------------------------------------
From long to ...
-------------------------------------------------------------------------
*/
LongUnaryOperator times = l -> l * l;
LongStream.of(1L, 2L, 3L).map(times)
/*.forEach(System.out::println)*/ ;
LongFunction<String> lf = l -> "toto";
LongStream.of(1L, 2L, 3L).mapToObj(lf);
/*
-------------------------------------------------------------------------
From double to ...
-------------------------------------------------------------------------
*/
DoubleToIntFunction dtif = d -> (int) d;
DoubleStream.of(1.3, 1.5, 1.6).mapToInt(dtif).forEach(System.out::println);
}
@Test
public void shouldConvertToStream() {
final Value<Integer> value = of(1, 2, 3);
final Stream<Integer> stream = value.toStream();
if (value.isSingleValued()) {
assertThat(stream).isEqualTo(Stream.of(1));
} else {
assertThat(stream).isEqualTo(Stream.of(1, 2, 3));
}
}
public static void main(String[] args) {
// check args
Stream.of(args).forEach(System.out::println);
// check .
Stream.of(new File(".").list()).forEach(System.out::println);
// check external libs
Client client = ClientBuilder.newClient();
String response = client.target("https://api.github.com/zen").request().get(String.class);
System.out.println(response);
}
public static void main(String[] args) {
Map<Integer, HashSet<String>> withSet =
Stream.of("jon", "andrew", "harvey", "bil")
.collect(Collectors.groupingBy(String::length, HashSet::new));
out.println(withSet);
}
static <T> Stream<T> inOrder(Tree<T> tree) {
if (tree.isLeaf()) {
return Stream.of(tree.getValue());
} else {
final List<Node<T>> children = tree.getChildren();
return children
.tail()
.foldLeft(Stream.<T>empty(), (acc, child) -> acc.appendAll(inOrder(child)))
.prepend(tree.getValue())
.prependAll(inOrder(children.head()));
}
}
static <T> Stream<T> preOrder(Tree<T> tree) {
return tree.getChildren()
.foldLeft(Stream.of(tree.getValue()), (acc, child) -> acc.appendAll(preOrder(child)));
}
