@Override
public List<City> parse(Stream<String> lines) {
LOG.debug("Parsing cities ...");
List<City> countries =
lines
.skip(2)
.map(
s -> {
// ad,arans,Arans,04,,42.5833333,1.5166667
String[] strings = s.split(",");
City mdo = new City();
mdo.setName(strings[2]);
mdo.setCountryCode(strings[0].toUpperCase());
if (StringUtils.isEmpty(strings[3])) {
LOG.debug("Skipping city {}", strings[2]);
// skip this city
return null;
}
try {
mdo.setRegion(Integer.parseInt(strings[3]));
} catch (NumberFormatException nfe) {
// skip this city
return null;
}
return mdo;
})
.filter(Objects::nonNull)
.collect(Collectors.toList());
LOG.debug("No. of parsed cities={}", countries.size());
return countries;
}
@Override
protected BackEndDataProvider<StrBean, SerializablePredicate<StrBean>> createDataProvider() {
return dataProvider =
new BackEndDataProvider<>(
query -> {
Stream<StrBean> stream =
data.stream().filter(t -> query.getFilter().orElse(s -> true).test(t));
if (!query.getSortOrders().isEmpty()) {
Comparator<StrBean> sorting =
query
.getSortOrders()
.stream()
.map(this::getComparator)
.reduce((c1, c2) -> c1.thenComparing(c2))
.get();
stream = stream.sorted(sorting);
}
List<StrBean> list =
stream
.skip(query.getOffset())
.limit(query.getLimit())
.collect(Collectors.toList());
list.forEach(s -> System.err.println(s.toString()));
return list.stream();
},
query ->
(int)
data.stream().filter(t -> query.getFilter().orElse(s -> true).test(t)).count());
}
public void filterFile() {
try (Stream<String> lines =
Files.lines(Paths.get(INPUT_FILE_NAME), Charset.forName("ISO-8859-1"))) {
lines
.skip(startLine)
.filter(
line -> {
Matcher m = PATTERN.matcher(line);
return m.matches();
})
.map(
line -> {
Matcher m = PATTERN.matcher(line);
m.matches();
return m.group(1);
})
.filter(
system -> {
if (system.equals(currentSystem)) {
return false;
} else {
currentSystem = system;
return true;
}
})
.map(system -> "jumped to " + system)
.forEach(System.out::println);
} catch (IOException ioe) {
System.out.println(ioe.toString());
}
}
/**
* @param path the path to number folders from.
* @return the folder number of a directory recursively
*/
static long countSubDirectories(Path path) {
try (Stream<Path> stream = Files.walk(path)) {
// skip first to avoid counting input directory
return stream.skip(1).filter(Files::isDirectory).count();
} catch (IOException e) {
throw new RuntimeException(e.getMessage(), e);
}
}
public static void main(String[] args) {
/** 例①： 打印数列的前10项 */
Stream<Long> fibonacci = Stream.generate(new FibonacciSupplier());
fibonacci.limit(10).forEach(System.out::println);
/** 例②： 打印数列的20~30项 */
Stream<Long> fibonacci2 = Stream.generate(new FibonacciSupplier());
List<Long> list = fibonacci2.skip(20).limit(10).collect(Collectors.toList());
list.forEach(System.out::println);
}
/**
* Update the dataset limit if it's too large for the system settings.
*
* @param metadata the dataset metadata to update.
*/
private void updateLimit(DataSetMetadata metadata) {
// auto closable block is really important to make sure the stream is closed after the limit is
// set
try (final Stream<DataSetRow> stream = contentStore.stream(metadata)) {
final Optional<DataSetRow> firstAfterLimit = stream.skip(sizeLimit).findAny();
if (firstAfterLimit.isPresent()) {
metadata.getContent().setLimit(sizeLimit);
}
}
}
public static HalRepresentationBuilder paginated(
String name,
String self,
Stream<? extends HalResource> stream,
long pageNumber,
long pageSize)
throws URISyntaxException {
long effectivePageNumber = pageNumber > 0 ? pageNumber - 1 : pageNumber;
long displayPageNumber = pageNumber <= 1 ? 1 : pageNumber;
HalRepresentationBuilder builder = new HalRepresentationBuilder();
builder
.addEmbedded(
name, stream.skip((effectivePageNumber) * pageSize).limit(pageSize).collect(toList()))
.addLink("next", new URI(self + "?page=" + (displayPageNumber + 1)))
.addLink(SELF, new URI(self + (displayPageNumber > 1 ? "?page=" + displayPageNumber : "")));
return builder;
}
public static void main(String[] args) {
Stream<Double> piStream = Stream.generate(new PiSupplier());
piStream.skip(1000000).limit(10).forEach(System.out::println);
System.out.println("-------------------------------------------");
Stream<Double> piStream_1 = Stream.generate(new PiSupplier());
piStream_1
.map(new EulerTransform())
.map(new EulerTransform())
.map(new EulerTransform())
.map(new EulerTransform())
.map(new EulerTransform())
.map(new EulerTransform())
.skip(10)
.limit(20)
.forEach(System.out::println);
}