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 <T> void show(String title, Stream<T> stream) {
final int SIZE = 10;
List<T> firstElements = stream.limit(SIZE + 1).collect(Collectors.toList());
System.out.print(title + ": ");
if (firstElements.size() <= SIZE) System.out.println(firstElements);
else {
firstElements.remove(SIZE);
String out = firstElements.toString();
System.out.println(out.substring(0, out.length() - 1) + ", ...]");
}
}
public Stream unmarshall(JsonUnmarshallerContext context) throws Exception {
Stream stream = new Stream();
int originalDepth = context.getCurrentDepth();
String currentParentElement = context.getCurrentParentElement();
int targetDepth = originalDepth + 1;
JsonToken token = context.getCurrentToken();
if (token == null) token = context.nextToken();
if (token == VALUE_NULL) return null;
while (true) {
if (token == null) break;
if (token == FIELD_NAME || token == START_OBJECT) {
if (context.testExpression("StreamArn", targetDepth)) {
context.nextToken();
stream.setStreamArn(context.getUnmarshaller(String.class).unmarshall(context));
}
if (context.testExpression("TableName", targetDepth)) {
context.nextToken();
stream.setTableName(context.getUnmarshaller(String.class).unmarshall(context));
}
if (context.testExpression("StreamLabel", targetDepth)) {
context.nextToken();
stream.setStreamLabel(context.getUnmarshaller(String.class).unmarshall(context));
}
} else if (token == END_ARRAY || token == END_OBJECT) {
if (context.getLastParsedParentElement() == null
|| context.getLastParsedParentElement().equals(currentParentElement)) {
if (context.getCurrentDepth() <= originalDepth) break;
}
}
token = context.nextToken();
}
return stream;
}
