java.util.stream.Stream#filter ( )源码实例Demo

/**
 * Returns ordered list of upgrades that should be applied to the current installation.
 * 
 * @param modelVersions The models and versions currently installed
 * @param localOnly Whether only local upgrades should be selected
 * @return ordered list of upgrades that should be applied
 */
public List<Upgrade> selectUpgrades(final Map<String, String> modelVersions, final boolean localOnly) {

  List<Upgrade> upgrades = upgradeIndex.entrySet().stream()
      .filter(e -> applies(modelVersions, e.getKey()))
      .map(e -> e.getValue())
      .collect(toList());

  List<String> problems = new ArrayList<>();
  upgrades.forEach(u -> checkUpgrade(u, problems));
  if (!problems.isEmpty()) {
    String message = String.format("Found %d problem(s) with upgrades:%n%s",
        problems.size(), problems.stream().collect(joining(lineSeparator())));
    throw new IllegalStateException(message);
  }

  Stream<UpgradeStep> upgradeSteps = order(modelVersions, upgrades);
  if (localOnly) {
    upgradeSteps = upgradeSteps.filter(step -> localModels.contains(step.getModel()));
  }

  return upgradeSteps
      .map(UpgradeStep::getUpgrade)
      .collect(toList());
}
 

public Optional<ImmutableList<Path>> getOptionalPathList(
    String section, String field, boolean resolve) {
  Optional<ImmutableList<String>> rawPaths =
      config.getOptionalListWithoutComments(section, field);

  if (!rawPaths.isPresent()) {
    return Optional.empty();
  }

  Stream<Path> paths = rawPaths.get().stream().map(this::getPathFromVfs);
  if (resolve) {
    paths = paths.map(projectFilesystem::getPathForRelativePath);
  }
  paths = paths.filter(projectFilesystem::exists);

  return Optional.of(paths.collect(ImmutableList.toImmutableList()));
}
 

@Override
public Stream<User> getMembers(DateTime when) {
    Stream<Student> students = Bennu.getInstance().getStudentsSet().stream();

    if (registered == null) {
        students = students.filter(student -> student.getAlumni() != null || hasConcludedRegistration(student) || isAlumni(student));
    }
    else if (registered) {
        students = students.filter(student -> student.getAlumni() != null && isAlumni(student));
    }
    else {
        students = students.filter(student -> student.getAlumni() == null && hasConcludedRegistration(student) && !isAlumni(student));
    }

    // If degree is set, filter out the alumni that didn't conclude the specified degree
    if (degree != null) {
        students = students.filter(this::isDegreeConcluded);
    }

    // Join students in a collection of users
    return students.map(student -> student.getPerson().getUser());
}
 

private void transform(final String normalisedName, String[] values, final ValueArrayConsumer consumer) throws
		IOException {
	Stream<String> stream = Arrays.stream(values);

	// Remove empty values.
	stream = stream.filter(value -> null != value && !value.isEmpty());

	// Remove duplicates.
	// Normalised to lowercase so that "GENERATOR" matches "Generator" (these inconsistent names can come from
	// HTML documents).
	if (values.length > 1 && deduplicateProperties.contains(fieldMap.get(normalisedName)
			.toLowerCase(Locale.ENGLISH))) {
		stream = stream.distinct();
	}

	values = stream.toArray(String[]::new);
	if (values.length > 0) {
		consumer.accept(normalisedName, values);
	}
}
 

@Override
public ExecutionStepWithResultName create(String resultName, boolean distinct, ExecutionStepWithResultName[] argumentsExecutionStep) {
    if (distinct) {
        throw new VertexiumCypherNotImplemented("distinct");
    }
    return new FunctionInvocationExecutionStep(getClass().getSimpleName(), resultName, argumentsExecutionStep) {
        @Override
        protected Object executeFunction(VertexiumCypherQueryContext ctx, Object[] arguments) {
            if (arguments.length > 3) {
                throw new VertexiumException("range function takes 2 or 3 arguments");
            }
            int arg0 = argumentToInt(arguments[0]);
            int arg1 = argumentToInt(arguments[1]);
            Stream<Integer> result = IntStream.rangeClosed(arg0, arg1).boxed();
            if (arguments.length == 3) {
                int step = argumentToInt(arguments[2]);
                if (step == 0) {
                    throw new VertexiumCypherArgumentErrorException("NumberOutOfRange: step must be greater than 0");
                }
                result = result.filter(i -> i % step == 0);
            }
            return result;
        }
    };
}
 

@VisibleForTesting
String[] getSearchableIndexes(final RepositoryQueryBuilder repoQuery) {
  Stream<Repository> repositories = StreamSupport
      .stream(repositoryManager.browse().spliterator(), false)
      .filter(SearchQueryServiceImpl::repoOnlineAndHasSearchIndexFacet);

  if (repoQuery.repositoryNames != null) {
    repositories = repositories
        .filter(r -> repoQuery.repositoryNames.contains(r.getName()));
  }

  if (repoQuery.skipContentSelectors) {
    // not post-filtering by content selector, so we must pre-filter repositories we can access
    repositories = repositories
        .filter(r -> securityHelper.allPermitted(new RepositoryViewPermission(r, BROWSE)));
  }

  return repositories
      .map(indexNamingPolicy::indexName)
      .toArray(String[]::new);
}
 

public Stream<AddressEntry> getAddressEntriesForAvailableBalanceStream() {
    Stream<AddressEntry> availableOrPayout = Stream.concat(btcWalletService.getAddressEntries(AddressEntry.Context.TRADE_PAYOUT)
            .stream(), btcWalletService.getFundedAvailableAddressEntries().stream());
    Stream<AddressEntry> available = Stream.concat(availableOrPayout,
            btcWalletService.getAddressEntries(AddressEntry.Context.ARBITRATOR).stream());
    available = Stream.concat(available, btcWalletService.getAddressEntries(AddressEntry.Context.OFFER_FUNDING).stream());
    return available.filter(addressEntry -> btcWalletService.getBalanceForAddress(addressEntry.getAddress()).isPositive());
}
 

private Iterator<GeoWaveRow> createIteratorForDataIndexReader(
    final RocksDBClient client,
    final DataIndexReaderParams dataIndexReaderParams) {
  final RocksDBDataIndexTable dataIndexTable =
      RocksDBUtils.getDataIndexTable(
          client,
          dataIndexReaderParams.getInternalAdapterStore().getTypeName(
              dataIndexReaderParams.getAdapterId()),
          dataIndexReaderParams.getAdapterId());
  Iterator<GeoWaveRow> iterator;
  if (dataIndexReaderParams.getDataIds() != null) {
    iterator = dataIndexTable.dataIndexIterator(dataIndexReaderParams.getDataIds());
  } else {
    iterator =
        dataIndexTable.dataIndexIterator(
            dataIndexReaderParams.getStartInclusiveDataId(),
            dataIndexReaderParams.getEndInclusiveDataId());
  }
  if (client.isVisibilityEnabled()) {
    Stream<GeoWaveRow> stream = Streams.stream(iterator);
    final Set<String> authorizations =
        Sets.newHashSet(dataIndexReaderParams.getAdditionalAuthorizations());
    stream = stream.filter(new ClientVisibilityFilter(authorizations));
    iterator = stream.iterator();
  }
  return iterator;
}
 

@Override
public void delete(Stream<FileMeta> fileMetaStream) {
  super.delete(
      fileMetaStream.filter(
          fileMeta -> {
            this.deleteFile(fileMeta);
            return true;
          }));
}
 

protected void rebuildView() {
   Stream<M> stream = StreamSupport.stream(delegate.spliterator(), false);
   if(filter != null) {
      stream = stream.filter(filter);
   }
   if(comparator != null) {
      stream = stream.sorted(comparator);
   }
   this.view = stream.collect(Collectors.toList());
   this.listeners.fireEvent(ViewModelEvent.changed());
}
 

@Override
public List<Map> get(DataFetchingEnvironment env) {
  if (env.getSource() instanceof SubjectReference) {
    final Set<String> dataSetIds = new HashSet<>();
    SubjectReference source = env.getSource();
    ContextData contextData = env.getContext();
    Stream<DataSet> dataSets = contextData.getUser()
      .map(user -> repo.getDataSetsWithReadAccess(user).stream())
      .orElseGet(() -> repo.getDataSets().stream().filter(d -> d.getMetadata().isPublished()));

    if (env.containsArgument("dataSetIds")) {
      dataSetIds.addAll(env.getArgument("dataSetIds"));
      dataSets = dataSets.filter(d -> dataSetIds.contains(d.getMetadata().getCombinedId()));
    }
    final String ownId = source.getDataSet().getMetadata().getCombinedId();
    return dataSets
      .filter(d -> !ownId.equals(d.getMetadata().getCombinedId()))
      .map(d -> {
        try (Stream<CursorQuad> quads = d.getQuadStore().getQuads(source.getSubjectUri())) {
          return tuple(d, quads.findAny());
        }
      })
      .filter(i -> i.getRight().isPresent())
      .map(i -> ImmutableMap.of(
        "metadata", new DataSetWithDatabase(i.getLeft(), env.<ContextData>getContext().getUserPermissionCheck()),
        "entity", new LazyTypeSubjectReference(i.getRight().get().getSubject(), i.getLeft())
      ))
      .collect(toList());

  }
  return Lists.newArrayList();
}
 

@Override
public Collection<SubscriptionEntity> search(SubscriptionQuery query) {
    try {
        logger.debug("Search subscriptions {}", query);

        SubscriptionCriteria.Builder builder = new SubscriptionCriteria.Builder()
                .apis(query.getApis())
                .applications(query.getApplications())
                .plans(query.getPlans())
                .from(query.getFrom())
                .to(query.getTo());

        if (query.getStatuses() != null) {
            builder.statuses(
            query.getStatuses().stream()
                    .map(subscriptionStatus -> Subscription.Status.valueOf(subscriptionStatus.name()))
                    .collect(Collectors.toSet()));
        }

        Stream<SubscriptionEntity> subscriptionsStream =
                subscriptionRepository.search(builder.build()).stream().map(this::convert);
        if (query.getApiKey() != null && !query.getApiKey().isEmpty()) {
            subscriptionsStream = subscriptionsStream.filter(subscriptionEntity -> {
                final Set<ApiKeyEntity> apiKeys = apiKeyService.findBySubscription(subscriptionEntity.getId());
                return apiKeys.stream().anyMatch(apiKeyEntity -> apiKeyEntity.getKey().equals(query.getApiKey()));
            });
        }
        return subscriptionsStream.collect(toList());
    } catch (TechnicalException ex) {
        logger.error("An error occurs while trying to search for subscriptions: {}", query, ex);
        throw new TechnicalManagementException(
                String.format("An error occurs while trying to search for subscriptions: %s", query), ex);
    }
}
 

private Stream<Attribute> filterPermission(
    Stream<Attribute> attrs, EntityTypePermission permission) {
  return attrs.filter(
      attr ->
          permissionService.hasPermission(
              new EntityTypeIdentity(attr.getEntity().getId()), permission));
}
 

private Stream<Person> filterEmail(Stream<Person> matches) {
    if (!Strings.isNullOrEmpty(email)) {
        if (matches == null) {
            return EmailAddress.findAllActiveAndValid(email).filter(Objects::nonNull).map(EmailAddress::getParty)
                    .filter(Objects::nonNull).filter(party -> party.isPerson()).map(Person.class::cast)
                    .filter(Objects::nonNull).filter(Objects::nonNull);
        } else {
            return matches.filter(p -> p.getEmailAddressStream()
                    .filter(emailAddress -> emailAddress.getValue().equals(email))
                    .filter(emailAddress -> emailAddress.isActiveAndValid()).findAny().isPresent());
        }
    }
    return matches;
}
 

@Test
public void testOptionalToStream() {
    Optional<String> op = Optional.ofNullable("String value");
    Stream<String> strOptionalStream = op.stream();
    Stream<String> filteredStream = strOptionalStream.filter((str) -> {
        return str != null && str.startsWith("String");
    });
    assertEquals(1, filteredStream.count());

}
 

private List<ICartHopperBehaviour<?>> getApplicableHopperBehaviours(EntityMinecart cart){
    Stream<ICartHopperBehaviour<?>> behaviours = RailManager.getInstance().getHopperBehaviours().stream();
    behaviours = behaviours.filter(hopperBehaviour -> interactEngine && hopperBehaviour instanceof CartHopperBehaviourItems || managingCart.hasCapability(hopperBehaviour.getCapability(), null));
    return behaviours.collect(Collectors.toList());
}
 

protected Accessor findAccessor(Class<?> targetClass, Cache<Class<?>, Accessor> cache, Kind kind, Set<Class<?>> visitedInterfaces) {
    Accessor accessor = findDeclaredAccessor(targetClass, kind);
    if (null != accessor) {
        return accessor;
    }

    if (inspectSuperclasses) {
        Class<?> superClass = targetClass.getSuperclass();
        if (null != superClass && Object.class != superClass) {
            accessor = getAccessor(superClass, cache, kind, visitedInterfaces);
            if (null != accessor && checkVisibility && !accessor.isVisibleTo(targetClass)) {
                accessor = null;
            }
        }
    }

    List<Accessor> superAccessors = new ArrayList<>();
    if (accessor != null) {
        if (superClassPriority) {
            return accessor;
        } else {
            superAccessors.add(accessor);
        }
    } 
    
    if (inspectInterfaces) {
        Stream<Accessor> accessorsByInterfaces = Stream.of(targetClass.getInterfaces())
            .filter(i -> !visitedInterfaces.contains(i))
            .peek(i -> visitedInterfaces.add(i))
            .map(i -> getAccessor(i, cache, kind, visitedInterfaces))
            .filter(Objects::nonNull);
        
        if (checkVisibility) {
            accessorsByInterfaces = accessorsByInterfaces.filter(a -> a.isVisibleTo(targetClass));
        }
        
        List<Accessor> accessors = accessorsByInterfaces
            //.limit(2)
            .collect(Collectors.toList());
        superAccessors.addAll(accessors);
    }
    
    
    switch (superAccessors.size()) {
        case 0: return null;
        case 1: return superAccessors.get(0);
        default:
            throw new IllegalStateException(
                "Ambiguity: class " + targetClass.getName() + " has more than one " +
                SchedulerProvider.class.getSimpleName() + " defined by inherited accessors:\n" +
                superAccessors.toString()
            );                    
    }
}
 

private void attack()
{
	// set entity
	ClientPlayerEntity player = MC.player;
	ClientWorld world = MC.world;
	
	if(player.getAttackCooldownProgress(0) < 1)
		return;
	
	double rangeSq = Math.pow(range.getValue(), 2);
	Stream<LivingEntity> stream = StreamSupport
		.stream(MC.world.getEntities().spliterator(), true)
		.filter(e -> e instanceof LivingEntity).map(e -> (LivingEntity)e)
		.filter(e -> !e.removed && e.getHealth() > 0)
		.filter(e -> player.squaredDistanceTo(e) <= rangeSq)
		.filter(e -> e != player)
		.filter(e -> !(e instanceof FakePlayerEntity))
		.filter(e -> !WURST.getFriends().contains(e.getEntityName()));
	
	if(filterPlayers.isChecked())
		stream = stream.filter(e -> !(e instanceof PlayerEntity));
	
	if(filterSleeping.isChecked())
		stream = stream.filter(e -> !(e instanceof PlayerEntity
			&& ((PlayerEntity)e).isSleeping()));
	
	if(filterFlying.getValue() > 0)
		stream = stream.filter(e -> {
			
			if(!(e instanceof PlayerEntity))
				return true;
			
			Box box = e.getBoundingBox();
			box = box.union(box.offset(0, -filterFlying.getValue(), 0));
			return world.doesNotCollide(box);
		});
	
	if(filterMonsters.isChecked())
		stream = stream.filter(e -> !(e instanceof Monster));
	
	if(filterPigmen.isChecked())
		stream = stream.filter(e -> !(e instanceof ZombifiedPiglinEntity));
	
	if(filterEndermen.isChecked())
		stream = stream.filter(e -> !(e instanceof EndermanEntity));
	
	if(filterAnimals.isChecked())
		stream = stream.filter(
			e -> !(e instanceof AnimalEntity || e instanceof AmbientEntity
				|| e instanceof WaterCreatureEntity));
	
	if(filterBabies.isChecked())
		stream = stream.filter(e -> !(e instanceof PassiveEntity
			&& ((PassiveEntity)e).isBaby()));
	
	if(filterPets.isChecked())
		stream = stream
			.filter(e -> !(e instanceof TameableEntity
				&& ((TameableEntity)e).isTamed()))
			.filter(e -> !(e instanceof HorseBaseEntity
				&& ((HorseBaseEntity)e).isTame()));
	
	if(filterVillagers.isChecked())
		stream = stream.filter(e -> !(e instanceof VillagerEntity));
	
	if(filterGolems.isChecked())
		stream = stream.filter(e -> !(e instanceof GolemEntity));
	
	if(filterInvisible.isChecked())
		stream = stream.filter(e -> !e.isInvisible());
	
	LivingEntity target =
		stream.min(priority.getSelected().comparator).orElse(null);
	if(target == null)
		return;
	
	WURST.getHax().autoSwordHack.setSlot();
	
	// face entity
	Rotation rotation = RotationUtils
		.getNeededRotations(target.getBoundingBox().getCenter());
	PlayerMoveC2SPacket.LookOnly packet = new PlayerMoveC2SPacket.LookOnly(
		rotation.getYaw(), rotation.getPitch(), MC.player.isOnGround());
	MC.player.networkHandler.sendPacket(packet);
	
	// attack entity
	MC.interactionManager.attackEntity(player, target);
	player.swingHand(Hand.MAIN_HAND);
}
 

@Override
public void update(Stream<RoleMembership> roleMembershipStream) {
  super.update(roleMembershipStream.filter(this::preUpdate));
}
 

public static <T> Stream<T> instancesOf(Stream<?> stream, Class<T> type) {
    return (Stream<T>) stream.filter(type::isInstance);
}