Java Stream.forEach方法代碼示例

import java.util.stream.Stream; //導入方法依賴的package包/類
public QuadBuilder mirror() {
	if(facingMap.containsKey(last)) {
		Stream<Vector3> stream = Arrays.stream(facingMap.get(last).getVectors());
		switch(last) {
			case DOWN:
			case UP:
				stream.forEach(vec -> {
					vec.subtract(0.5D).rotate(EnumFacing.Axis.Y, 180).add(0.5D);
				});
				break;
			case NORTH:
			case SOUTH:
				stream.forEach(vec -> {
					vec.subtract(0.5D).rotate(EnumFacing.Axis.X, 180).add(0.5D);
				});
				break;
			case EAST:
			case WEST:
				stream.forEach(vec -> {
					vec.subtract(0.5D).rotate(EnumFacing.Axis.Z, 180).add(0.5D);
				});
				break;
		}
	}
	return this;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
@SuppressWarnings("unchecked")
public static Class<? extends Packet>[] toArray(Stream<Class<? extends Packet>> packets) {
    TreeMap<Integer, Class<? extends Packet>> map = new TreeMap<>();

    packets.forEach(packet -> {
        PacketInfo info = packet.getAnnotation(PacketInfo.class);
        map.put(info.id(), packet);
    });

    if (map.size() == 0) {
        return new Class[0];
    }

    Class<? extends Packet>[] array = new Class[map.lastKey() + 1];
    map.forEach((id, packet) -> array[id] = packet);

    return array;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
private void parseReleaseGroupMetaFile(List<Album> albums) {

        Map<String, List<Album>> releaseGroupIdAlbumMap = albums.stream()
                .filter(album -> !StringUtils.isEmpty(album.getReleaseGroupId()))
                .collect(Collectors.groupingBy(Album::getReleaseGroupId));

        //read file into stream, try-with-resources
        try (Stream<String> stream = Files.lines(Paths.get(releaseGroupMetaFilePath))) {
            Stream<String[]> rows = stream.map(strRow -> strRow.split(TAB_SYMBOL));
            rows.forEach(row -> {
                List<Album> albumList = releaseGroupIdAlbumMap.get(row[0]);
                if (albumList != null) {
                    JsonDateDay releasedDate = ParserUtils.parseDateDay(row[2], row[3], row[4]);
                    albumList.forEach(album -> album.setReleasedDate(releasedDate));
                }
            });
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
 

import java.util.stream.Stream; //導入方法依賴的package包/類
private List<CodePoint> readCodePoints() {
    try {
        List<CodePoint> codePoints = new ArrayList<>();
        Stream<String> stream = new BufferedReader(new InputStreamReader(
                getClass().getResourceAsStream("/codepoints"))).lines();

        stream.forEach(line -> {
            String[] parts = line.split("\\s", 2);
            int code = Integer.parseInt(parts[1], 16);
            codePoints.add(new CodePoint(parts[0], code));
        });

        return codePoints;
    } catch(Exception e) {
        throw new RuntimeException("Failed to read code points", e);
    }
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
public void fixPermissions() throws IOException {
    try {
        Set<PosixFilePermission> filePermissions = Files.getPosixFilePermissions(executable);
        Stream<PosixFilePermission> requiredPermissions = Stream
            .of(PosixFilePermission.OWNER_EXECUTE, PosixFilePermission.GROUP_EXECUTE);

        requiredPermissions.forEach(requiredPermission -> {
            filePermissions.add(requiredPermission);
        });
        Files.setPosixFilePermissions(executable, filePermissions);
    } catch (UnsupportedOperationException e) {
        // windows -.-
    }
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
private void spread() {
    World world = GameState.getGameWorld();
    ThreadLocalRandom random = ThreadLocalRandom.current();
    int spreadSize = UHC.getInstance().getMainConfig().getWorldBorderInitialSize();
    Stream<? extends Player> players = Bukkit.getServer().getOnlinePlayers().stream().filter(player -> player.getGameMode() != GameMode.SPECTATOR);

    players.forEach(player -> player.teleport(generateSafe(spreadSize, world, random)));
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
/**
 * 刪除不影響流
 */
public void test2(){
	c1.add(1);
	c1.add(2);
	c1.add(3);
	c2.add(3);
	c2.add(4);
	c2.add(5);
	Stream<Integer> s=Stream.concat(c1.stream(), c2.stream());
	c1.remove(1);
	s.forEach(a->{
		System.out.println(a);
	});;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
public void createCustomArrayStream(){
	Employee emp1 = new Employee();
	Employee emp2 = new Employee();
	Stream<Employee> emptyRecs = Stream.of(emp1, emp2);
	Consumer<Employee> showRecs = System.out::println;
	emptyRecs.forEach(showRecs);
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
/**
 * Handle snippet reevaluation commands: {@code /<id>}. These commands are a
 * sequence of ids and id ranges (names are permitted, though not in the
 * first position. Support for names is purposely not documented).
 *
 * @param rawargs the whole command including arguments
 */
private void rerunHistoryEntriesById(String rawargs) {
    ArgTokenizer at = new ArgTokenizer("/<id>", rawargs.trim().substring(1));
    at.allowedOptions();
    Stream<Snippet> stream = argsOptionsToSnippets(state::snippets, sn -> true, at);
    if (stream != null) {
        // successfully parsed, rerun snippets
        stream.forEach(sn -> rerunSnippet(sn));
    }
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
public static void main(String[] args) {
	List<String> lines = DataStub.getLines();
	Stream<String> stream = lines.stream();
	stream.reduce((a, b) -> a.length() > b.length() ? a : b)
	    .ifPresent(System.out::println);

	// below line will throw the exception
	stream.forEach(System.out::println);
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
default <T extends JsonElement> JsonObjectBuilder addAll(Stream<Map.Entry<String, T>> stream, boolean deepCopy) {
    Preconditions.checkNotNull(stream, "stream");
    stream.forEach(e -> {
        if (e == null || e.getKey() == null) {
            return;
        }
        add(e.getKey(), e.getValue(), deepCopy);
    });
    return this;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
public static List<String> complete(String prefix, Stream<String> options) {
    final String prefixLower = prefix.toLowerCase();
    final int pos = prefixLower.lastIndexOf(' ');
    final List<String> matches = new ArrayList<>();
    options.forEach(option -> {
        if(option.toLowerCase().startsWith(prefixLower)) {
            matches.add(pos == -1 ? option : option.substring(pos + 1));
        }
    });
    Collections.sort(matches);
    return matches;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
/**
 * Chronosome is valid if:
 * <ul>
 * <li>all the ChronoGenes are valid</li>
 * <li>no duplicate genes</li>
 * <li>no duplicate ChronoFrequency</li>
 * <li>ChronoPatterns don't share temporal inclusions</li>
 * </ul>
 *
 * @return Chronosome validity
 */
@Override
public boolean isValid() {
    //dupe genes check
    final AtomicBoolean dupeGenes = new AtomicBoolean(false);
    Stream<ChronoUnit> chronoUnits = getGenes().stream()
            .filter(chronoGene -> chronoGene.getAllele() instanceof ChronoPattern)
            .map(chronoGene -> ((ChronoPattern) chronoGene.getAllele()).getChronoScaleUnit().getChronoUnit())
            .distinct();
    chronoUnits.forEach(
            chronoUnit -> {
                ISeq<ChronoPattern> unitPatterns = getGenes().stream()
                        .filter(chronoGene -> chronoGene.getAllele() instanceof ChronoPattern)
                        .map(chronoGene -> (ChronoPattern) chronoGene.getAllele())
                        .filter(chronoPattern -> chronoPattern.getChronoScaleUnit().getChronoUnit().equals(chronoUnit))
                        .collect(ISeq.toISeq());
                if (unitPatterns.size() > 1) {
                    Set<Integer> temporalInclusionSet = Sets.newHashSet();
                    unitPatterns.forEach(
                            chronoPattern -> {
                                if (!chronoPattern.getTemporalValue().isPresent()) {
                                    dupeGenes.set(true);
                                } else {
                                    int patternValue = chronoPattern.getTemporalValue().getAsInt();
                                    if (temporalInclusionSet.contains(patternValue)) {
                                        dupeGenes.set(true);
                                    } else {
                                        temporalInclusionSet.add(patternValue);
                                    }
                                }
                            }
                    );
                }
            }
    );
    if (dupeGenes.get()) {
        return false;
    }

    boolean hasChronoFrequency = false;
    for (ChronoGene gene : genes) {
        if (!gene.isValid()) {
            return false;
        }

        if (gene.getAllele() instanceof ChronoFrequency) {
            if (hasChronoFrequency) {
                //multiple chrono frequencies aren't allowed
                return false;
            }
            hasChronoFrequency = true;
        }
    }
    return true;
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
@Test
public void testWeatherServiceLazyAndCache(){
    /**
     * Arrange WeatherService --> WeatherWebApi --> Countify --> FileRequest
     */
    ICounter<String, Stream<String>> req = Countify.of(new FileRequest()::getContent);
    // Function<String, Iterable<String>> cache = Cache.memoize(req);
    WeatherService api = new WeatherServiceCache(new WeatherWebApi(req::apply));
    /**
     * Act and Assert
     */
    Stream<Location> locals = api.search("Porto");
    assertEquals(1, req.getCount());
    locals = locals.filter(l -> l.getLatitude() > 0 );
    assertEquals(1, req.getCount());
    /**
     * Counts 1 request when iterates to get the first Location
     */
    Location loc = locals.iterator().next();
    assertEquals(1, req.getCount());
    Stream<WeatherInfo> infos = loc.getPastWeather(of(2017,02,01), of(2017,02,28));
    assertEquals(2, req.getCount());
    infos = infos.filter(info ->
            info.getDescription().toLowerCase().contains("sun"));
    Stream<Integer> temps = infos.map(WeatherInfo::getTempC);
    temps = temps.distinct();
    assertEquals(2, req.getCount());
    /**
     * When we iterate over the pastWeather then we make one more request
     */
    assertEquals(5, temps.count()); // iterates all items
    assertEquals(2, req.getCount());
    temps = api.search("Porto")
            .findFirst().get()
            .getPastWeather(of(2017,02,01), of(2017,02,28))
            .filter(info -> info.getDescription().toLowerCase().contains("sun"))
            .map(WeatherInfo::getTempC);
    assertEquals((long) 20, (long) temps.skip(2).findFirst().get()); // another iterator
    assertEquals(3, req.getCount());
    /**
     * getting a sub-interval of past weather should return from cache
     */
    infos = loc.getPastWeather(of(2017,02,05), of(2017,02,18));
    infos.iterator().next();
    assertEquals(3, req.getCount());
    /**
     * getting a new interval gets from IO
     */
    infos = loc.getPastWeather(of(2017,02,15), of(2017,03,15));
    infos.forEach((item) -> {}); // Consume all to add all itens in cache
    assertEquals(4, req.getCount());
    /**
     * getting a sub-interval of past weather should return from cache
     */
    infos = loc.getPastWeather(of(2017,02,20), of(2017,03,10));
    infos.iterator().next();
    assertEquals(4, req.getCount());
}
 

import java.util.stream.Stream; //導入方法依賴的package包/類
/**
 * Parses all class files from the given archive stream and returns
 * all target locations.
 */
public Set<Location> parse(Stream<? extends Archive> archiveStream) {
    archiveStream.forEach(archive -> parse(archive, CLASS_FINDER));
    return waitForTasksCompleted();
}