本文整理了Java中org.apache.commons.rdf.api.Dataset.stream()方法的一些代码示例，展示了Dataset.stream()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Dataset.stream()方法的具体详情如下：
包路径：org.apache.commons.rdf.api.Dataset
类名称：Dataset
方法名：stream

Dataset.stream介绍

[英]Get all quads contained by the dataset.

The iteration does not contain any duplicate quads, as determined by the Quad#equals(Object) method for each Quad.

The behaviour of the Stream is not specified if #add(Quad), #remove(Quad) or #clear() are called on the Dataset before it terminates.

Implementations may throw ConcurrentModificationException from Stream methods if they detect a conflict while the Stream is active.
[中]获取数据集包含的所有四边形。
迭代不包含任何重复的四边形，这是由每个四边形的Quad#equals（Object）方法确定的。
如果在数据集终止之前对数据集调用了#add（Quad）、#remove（Quad）或#clear（），则不会指定流的行为。
如果流方法在流处于活动状态时检测到冲突，则实现可能会从流方法中抛出ConcurrentModificationException。

代码示例

代码示例来源：origin: trellis-ldp/trellis

@Override
public Stream<Quad> stream() {
  return dataset.stream().map(Quad.class::cast);
}

代码示例来源：origin: org.trellisldp/trellis-api

@Override
public Stream<Quad> stream() {
  return dataset.stream().map(Quad.class::cast);
}

代码示例来源：origin: org.trellisldp/trellis-rosid-common

/**
 * Stream out the added quads
 * @return the added quads
 */
public Stream<Quad> getAdded() {
  return dataset.stream().filter(q -> !existing.contains(q)).map(q -> (Quad) q);
}

代码示例来源：origin: org.apache.commons/commons-rdf-simple

@Override
public Stream<? extends Triple> stream(final BlankNodeOrIRI subject, final IRI predicate, final RDFTerm object) {
  final Stream<Triple> stream = dataset.stream(unionOrNamedGraph(), subject, predicate, object).map(Quad::asTriple);
  if (unionGraph) {
    // remove duplicates
    return stream.distinct();
  }
  return stream;
}

代码示例来源：origin: org.trellisldp/trellis-rosid-common

/**
 * Serialize a dataset
 * @param dataset the dataset
 * @return a string
 */
public static String serialize(final Dataset dataset) {
  if (nonNull(dataset)) {
    return serialize(dataset.stream().collect(toList()));
  }
  return "";
}

代码示例来源：origin: org.trellisldp/trellis-rosid-common

@Override
public Collection<IRI> getTargetTypes() {
  return data.stream().filter(quad -> quad.getGraphName().filter(graphsForTypes::contains).isPresent())
    .filter(quad -> quad.getPredicate().equals(type)).map(Quad::getObject)
    .filter(term -> term instanceof IRI).map(term -> (IRI) term).distinct().collect(toList());
}

代码示例来源：origin: org.trellisldp/trellis-rosid-common

/**
 * Get the PROV.endedAtTime quad, wrapped in a Stream
 * @param identifier the identifier
 * @param dataset the dataset
 * @param time the time
 * @return the quad
 */
public static Stream<Quad> endedAtQuad(final IRI identifier, final Dataset dataset, final Instant time) {
  return dataset.stream(of(PreferAudit), identifier, wasGeneratedBy, null)
    .map(Quad::getObject).filter(term -> term instanceof BlankNodeOrIRI)
    .map(term -> (BlankNodeOrIRI) term)
    .map(term -> (Quad) rdf.createQuad(PreferAudit, term, endedAtTime,
        rdf.createLiteral(time.toString(), dateTime))).limit(1);
}

代码示例来源：origin: trellis-ldp/trellis

public TestResource(final IRI id, final Dataset quads) {
  this.id = id;
  quads.stream().forEach(dataset::add);
}

代码示例来源：origin: trellis-ldp/trellis

@Override
public Stream<Quad> stream() {
  return dataset.stream().map(Quad.class::cast);
}

代码示例来源：origin: org.trellisldp/trellis-triplestore

/**
 * TODO Replace when COMMONSRDF-74 is released.
 *
 * @param dataset a Commons RDF {@link Dataset}
 * @return a Jena {@link org.apache.jena.query.Dataset}
 */
public static org.apache.jena.query.Dataset asJenaDataset(final Dataset dataset) {
  final DatasetGraph dsg;
  if (dataset instanceof JenaDataset) {
    dsg = ((JenaDataset) dataset).asJenaDatasetGraph();
  } else {
    dsg = DatasetGraphFactory.createGeneral();
    dataset.stream().map(rdf::asJenaQuad).forEach(dsg::add);
  }
  return wrap(dsg);
}

代码示例来源：origin: trellis-ldp/trellis

/**
 * TODO Replace when COMMONSRDF-74 is released.
 *
 * @param dataset a Commons RDF {@link Dataset}
 * @return a Jena {@link org.apache.jena.query.Dataset}
 */
public static org.apache.jena.query.Dataset asJenaDataset(final Dataset dataset) {
  final DatasetGraph dsg;
  if (dataset instanceof JenaDataset) {
    dsg = ((JenaDataset) dataset).asJenaDatasetGraph();
  } else {
    dsg = DatasetGraphFactory.createGeneral();
    dataset.stream().map(rdf::asJenaQuad).forEach(dsg::add);
  }
  return wrap(dsg);
}

代码示例来源：origin: org.trellisldp/trellis-rosid-common

private ProducerRecord<String, String> buildContainmentMessage(final String topic, final IRI resource,
    final Resource parent, final Dataset dataset) throws Exception {
  try (final Dataset data = dataset.stream(of(PreferAudit), null, null, null).map(auditTypeMapper)
      .collect(toDataset())) {
    data.add(PreferContainment, parent.getIdentifier(), contains, resource);
    return new ProducerRecord<>(topic, parent.getIdentifier().getIRIString(), serialize(data));
  }
}

代码示例来源：origin: trellis-ldp/trellis

@Override
  public String toString() {
    return asDataset().stream()
            .map(q -> format("%1$s %2$s %3$s %4$s .",
                    q.getSubject().ntriplesString(),
                    q.getPredicate().ntriplesString(),
                    q.getObject().ntriplesString(),
                    q.getGraphName().map(BlankNodeOrIRI::ntriplesString).orElse("")))
            .collect(joining("\n"));
  }
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void stream() throws Exception {
  assertEquals(new DummyQuad(), dataset.stream().findAny().get());
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void streamDefaultGraphNameByPattern() throws Exception {
  // Explicitly select in only the default graph Optional.empty()
  final Optional<? extends Quad> aliceTopic = dataset.stream(Optional.empty(), null, null, null).findAny();
  assertTrue(aliceTopic.isPresent());
  // COMMONSRDF-55: should not be <urn:x-arq:defaultgraph> or similar
  assertNull(aliceTopic.get().getGraphName().orElse(null));
  assertFalse(aliceTopic.get().getGraphName().isPresent());
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void streamDefaultGraphNameAlice() throws Exception {
  // null below would match in ANY graph (including default graph)
  final Optional<? extends Quad> aliceTopic = dataset.stream(null, alice, isPrimaryTopicOf, null).findAny();
  assertTrue(aliceTopic.isPresent());
  // COMMONSRDF-55: should not be <urn:x-arq:defaultgraph> or similar
  assertNull(aliceTopic.get().getGraphName().orElse(null));
  assertFalse(aliceTopic.get().getGraphName().isPresent());
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void streamFiltered() throws Exception {
  assertEquals(new DummyQuad(), dataset.stream(null, null, null, null).findAny().get());
  assertEquals(new DummyQuad(),
      dataset.stream(null, new DummyIRI(1), new DummyIRI(2), new DummyIRI(3)).findAny().get());
  assertFalse(dataset.stream(null, new DummyIRI(0), new DummyIRI(0), new DummyIRI(0)).findAny().isPresent());
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void getQuads() throws Exception {
  long quadCount;
  try (Stream<? extends Quad> stream = dataset.stream()) {
    quadCount = stream.count();
  }
  assertTrue(quadCount > 0);
  try (Stream<? extends Quad> stream = dataset.stream()) {
    assertTrue(stream.allMatch(t -> dataset.contains(t)));
  }
  // Check exact count
  Assume.assumeNotNull(bnode1, bnode2, aliceName, bobName, secretClubName, companyName, bobNameQuad);
  assertEquals(10, quadCount);
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void contains() throws Exception {
  assertFalse(dataset.contains(null, bob, knows, alice)); // or so he claims..
  assertTrue(dataset.contains(Optional.of(graph1), alice, knows, bob));
  try (Stream<? extends Quad> stream = dataset.stream()) {
    final Optional<? extends Quad> first = stream.skip(4).findFirst();
    Assume.assumeTrue(first.isPresent());
    final Quad existingQuad = first.get();
    assertTrue(dataset.contains(existingQuad));
  }
  final Quad nonExistingQuad = factory.createQuad(graph2, bob, knows, alice);
  assertFalse(dataset.contains(nonExistingQuad));
  // An existing quad
  final Quad quad = factory.createQuad(graph1, alice, knows, bob);
  // FIXME: Should not this always be true?
   assertTrue(dataset.contains(quad));
}

代码示例来源：origin: org.apache.commons/commons-rdf-api

@Test
public void getGraph2() throws Exception {
  // graph2 should be present, even if is named by a BlankNode
  // We'll look up the potentially mapped graph2 blanknode
  final BlankNodeOrIRI graph2Name = (BlankNodeOrIRI) dataset.stream(Optional.empty(), bob, isPrimaryTopicOf, null)
      .map(Quad::getObject).findAny().get();
  try (final Graph g2 = dataset.getGraph(graph2Name).get()) {
    assertEquals(4, g2.size());
    final Triple bobNameTriple = bobNameQuad.asTriple();
    assertTrue(g2.contains(bobNameTriple));
    assertTrue(g2.contains(bob, member, bnode1));
    assertTrue(g2.contains(bob, member, bnode2));
    assertFalse(g2.contains(bnode1, name, secretClubName));
    assertTrue(g2.contains(bnode2, name, companyName));
  }
}