Beispiel #1
0
 /**
  * @param t the Throwable to get the causal chain from.
  * @return the entire chain of causes, including the given Throwable.
  */
 public static Stream<Throwable> causalChainOf(Throwable t) {
   Stream.Builder<Throwable> causes = Stream.builder();
   for (Throwable cause = t; cause != null; cause = cause.getCause()) {
     causes.add(cause);
   }
   return causes.build();
 }
  public static void main(String[] args) {

    final List<Pair> generateDemoValues = new PairListGenerator() {}.generateDemoValues();

    // Stream from Values
    final Stream<Pair> fromValues = Stream.of(new Pair(), new Pair());

    // Stream from Array
    final Pair[] pairs = {new Pair(), new Pair()};
    final Stream<Pair> fromArray = Stream.of(pairs);

    // Stream from List
    final Stream<Pair> fromList = generateDemoValues.stream();

    // Stream from String
    final Stream<String> abc = Stream.of("ABC");
    final Stream<IntStream> of = Stream.of("ABC".chars());
    final Stream<String> splitOf = Stream.of("A,B,C".split(","));

    // Stream from builder
    final Stream<Pair> builderPairStream = Stream.<Pair>builder().add(new Pair()).build();

    // Stream to Array
    final Pair[] toArray = generateDemoValues.stream().toArray(Pair[]::new);
    // Stream to List
    final List<Pair> toList = generateDemoValues.stream().collect(Collectors.toList());

    // Stream to Set
    final Set<Pair> toSet = generateDemoValues.stream().collect(Collectors.toSet());

    // Stream to Map
    final Map<Integer, List<Pair>> collectedToMap =
        generateDemoValues.stream().collect(Collectors.groupingBy(Pair::getId));
    System.out.println("collectedToMap.size() = " + collectedToMap.size());

    for (final Map.Entry<Integer, List<Pair>> entry : collectedToMap.entrySet()) {
      System.out.println("entry = " + entry);
    }
  }