Example usage for java.util Collection stream

Introduction

In this page you can find the example usage for java.util Collection stream.

Prototype

default Stream<E> stream()

Source Link

Document

Returns a sequential Stream with this collection as its source.

Usage

From source file:Main.java

public static <K, V> Map<K, Collection<V>> toMap(final Collection<? extends V> items,
        final Function<V, K> mapper) {
    Map<K, Collection<V>> buffer = new HashMap<K, Collection<V>>();
    // TODO this isn't probably thread-safe
    items.stream().forEach(item -> {
        K key = mapper.apply(item);//from w w  w . j  a va2s  . c om
        Collection<V> c = buffer.getOrDefault(key, new ArrayList<V>());
        c.add(item);
        buffer.put(key, c);
    });
    return buffer;
}

From source file:org.fede.util.Util.java

public static <T> String list(Collection<T> elements, String separator) {
    return elements.stream().map(e -> e.toString()).collect(Collectors.joining(separator));
}

From source file:org.lightjason.agentspeak.action.builtin.rest.IBaseRest.java

/**
 * transforms a collection into a term stream
 *
 * @param p_collection collection/*from w ww.  ja v  a  2s.c  om*/
 * @return term stream
 */
@Nonnull
private static Stream<ITerm> flatcollection(@Nonnull final Collection<?> p_collection) {
    return p_collection.stream().flatMap(IBaseRest::flatterm);
}

From source file:dk.dma.db.cassandra.CassandraConnection.java

private static boolean seedsContainPortNumbers(Collection<String> connectionPoints) {
    requireNonNull(connectionPoints);//  w w  w  .j av a2s. com
    return connectionPoints.stream().filter(cp -> StringUtils.countMatches(cp, ":") == 1).count() > 0;
}

From source file:ch.sdi.core.util.ClassUtil.java

/**
 * Lists all types in the given package (recursive) which are annotated by the given annotation and
 * are assignable from given class./*from w w w  .j a  v a2 s  . c  om*/
 * <p>
 * All types which match the criteria are returned, no further checks (interface, abstract, embedded,
 * etc. are performed.
 * <p>
 *
 * @param aClass
 *        the desired (base) class
 * @param aAnnotation
 *        the desired annotation type
 * @param aRoot
 *        the package name where to start the search. Must not be empty. And not start
 *        with 'org.springframework' (cannot parse springs library itself).
 * @return a list of found types
 */
@SuppressWarnings("unchecked")
public static <T> Collection<Class<T>> findCandidatesByAnnotation(Class<T> aClass,
        Class<? extends Annotation> aAnnotation, String aRoot) {
    Collection<Class<T>> result = new ArrayList<Class<T>>();

    Collection<? extends Class<?>> candidates = findCandidatesByAnnotation(aAnnotation, aRoot);

    candidates.stream().peek(c -> myLog.trace("inspecting candidate " + c.getName()))
            .filter(c -> aClass.isAssignableFrom(c))
            .peek(c -> myLog.debug("candidate " + c.getName() + " is of desired type"))
            .forEach(c -> result.add((Class<T>) c));

    return result;

}

From source file:com.cloudera.oryx.common.OryxTest.java

private static <T> Collection<T> minus(Collection<? extends T> a, Collection<T> b) {
    return a.stream().filter(t -> !b.contains(t)).collect(Collectors.toList());
}

From source file:com.github.horrorho.inflatabledonkey.cloud.clients.SnapshotClient.java

public static List<Snapshot> snapshots(HttpClient httpClient, CloudKitty kitty, ProtectionZone zone,
        Collection<SnapshotID> snapshotIDs) throws IOException {

    if (snapshotIDs.isEmpty()) {
        return new ArrayList<>();
    }//from w  w w.j  a  v a  2  s .  c  om

    List<String> snapshots = snapshotIDs.stream().map(SnapshotID::id).collect(Collectors.toList());

    List<CloudKit.RecordRetrieveResponse> responses = kitty.recordRetrieveRequest(httpClient, "mbksync",
            snapshots);
    logger.debug("-- manifests() - responses: {}", responses);

    return responses.stream().filter(CloudKit.RecordRetrieveResponse::hasRecord)
            .map(CloudKit.RecordRetrieveResponse::getRecord).map(r -> manifests(r, zone))
            .filter(Optional::isPresent).map(Optional::get).collect(Collectors.toList());
}

From source file:com.github.horrorho.liquiddonkey.cloud.data.FileGroups.java

static ICloud.MBSFileAuthTokens fileIdToSignatureAuthTokens(Collection<ICloud.MBSFile> files,
        Collection<ICloud.MBSFileAuthToken> fileIdAuthTokens) {

    Map<ByteString, ByteString> fileIdToSignature = files.stream()
            .collect(Collectors.toMap(ICloud.MBSFile::getFileID, ICloud.MBSFile::getSignature));

    // Somewhat confusing proto definitions.
    // Each file is requested by file signature/ checksum not by it's FileID
    ICloud.MBSFileAuthTokens.Builder builder = ICloud.MBSFileAuthTokens.newBuilder();
    fileIdAuthTokens.stream().forEach(token -> builder.addTokens(ICloud.MBSFileAuthToken.newBuilder()
            .setFileID(fileIdToSignature.get(token.getFileID())).setAuthToken(token.getAuthToken()).build()));
    return builder.build();
}

From source file:io.neba.core.util.JsonUtil.java

/**
 * @param collection must not be <code>null</code>.
 *//*www . j a va2  s.c  om*/
public static String toJson(Collection<?> collection) {
    if (collection == null) {
        throw new IllegalArgumentException("Method parameter collection must not be null");
    }

    return collection.stream().map(JsonUtil::toJson).reduce((l, r) -> l + "," + r).map(s -> '[' + s + ']')
            .orElse("[]");
}

From source file:com.cloudera.oryx.common.OryxTest.java

private static <T> String abbreviatedToString(Collection<T> c) {
    return c.size() <= 16 ? c.toString() : c.stream().limit(16).collect(Collectors.toList()) + "...";
}