Java Count类代码示例

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Override
public PCollection<KV<String, List<CompletionCandidate>>> expand(PCollection<String> input) {
  PCollection<CompletionCandidate> candidates = input
    // First count how often each token appears.
    .apply(Count.<String>perElement())

    // Map the KV outputs of Count into our own CompletionCandiate class.
    .apply("CreateCompletionCandidates", ParDo.of(
        new DoFn<KV<String, Long>, CompletionCandidate>() {
          @ProcessElement
          public void processElement(ProcessContext c) {
            c.output(new CompletionCandidate(c.element().getKey(), c.element().getValue()));
          }
        }));

  // Compute the top via either a flat or recursive algorithm.
  if (recursive) {
    return candidates
      .apply(new ComputeTopRecursive(candidatesPerPrefix, 1))
      .apply(Flatten.<KV<String, List<CompletionCandidate>>>pCollections());
  } else {
    return candidates
      .apply(new ComputeTopFlat(candidatesPerPrefix, 1));
  }
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Override
public PCollection<TableRow> expand(PCollection<TableRow> rows) {

  // row... => month...
  PCollection<Integer> tornadoes = rows.apply(
      ParDo.of(new ExtractTornadoesFn()));

  // month... => <month,count>...
  PCollection<KV<Integer, Long>> tornadoCounts =
      tornadoes.apply(Count.<Integer>perElement());

  // <month,count>... => row...
  PCollection<TableRow> results = tornadoCounts.apply(
      ParDo.of(new FormatCountsFn()));

  return results;
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Test
@Category({ValidatesRunner.class, UsesCustomWindowMerging.class})
public void testMergingCustomWindows() {
  Instant startInstant = new Instant(0L);
  List<TimestampedValue<String>> input = new ArrayList<>();
  PCollection<String> inputCollection =
      pipeline.apply(
          Create.timestamped(
              TimestampedValue.of("big", startInstant.plus(Duration.standardSeconds(10))),
              TimestampedValue.of("small1", startInstant.plus(Duration.standardSeconds(20))),
              // This one will be outside of bigWindow thus not merged
              TimestampedValue.of("small2", startInstant.plus(Duration.standardSeconds(39)))));
  PCollection<String> windowedCollection =
      inputCollection.apply(Window.into(new CustomWindowFn<String>()));
  PCollection<Long> count =
      windowedCollection.apply(Combine.globally(Count.<String>combineFn()).withoutDefaults());
  // "small1" and "big" elements merged into bigWindow "small2" not merged
  // because timestamp is not in bigWindow
  PAssert.that("Wrong number of elements in output collection", count).containsInAnyOrder(2L, 1L);
  pipeline.run();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Test
@Category({ValidatesRunner.class, UsesCustomWindowMerging.class})
public void testMergingCustomWindowsKeyedCollection() {
  Instant startInstant = new Instant(0L);
  PCollection<KV<Integer, String>> inputCollection =
      pipeline.apply(
          Create.timestamped(
              TimestampedValue.of(
                  KV.of(0, "big"), startInstant.plus(Duration.standardSeconds(10))),
              TimestampedValue.of(
                  KV.of(1, "small1"), startInstant.plus(Duration.standardSeconds(20))),
              // This element is not contained within the bigWindow and not merged
              TimestampedValue.of(
                  KV.of(2, "small2"), startInstant.plus(Duration.standardSeconds(39)))));
  PCollection<KV<Integer, String>> windowedCollection =
      inputCollection.apply(Window.into(new CustomWindowFn<KV<Integer, String>>()));
  PCollection<Long> count =
      windowedCollection.apply(
          Combine.globally(Count.<KV<Integer, String>>combineFn()).withoutDefaults());
  // "small1" and "big" elements merged into bigWindow "small2" not merged
  // because it is not contained in bigWindow
  PAssert.that("Wrong number of elements in output collection", count).containsInAnyOrder(2L, 1L);
  pipeline.run();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
public static void addCountingAsserts(PCollection<Long> input, long numElements) {
  // Count == numElements
  PAssert
    .thatSingleton(input.apply("Count", Count.<Long>globally()))
    .isEqualTo(numElements);
  // Unique count == numElements
  PAssert
    .thatSingleton(input.apply(Distinct.<Long>create())
                        .apply("UniqueCount", Count.<Long>globally()))
    .isEqualTo(numElements);
  // Min == 0
  PAssert
    .thatSingleton(input.apply("Min", Min.<Long>globally()))
    .isEqualTo(0L);
  // Max == numElements-1
  PAssert
    .thatSingleton(input.apply("Max", Max.<Long>globally()))
    .isEqualTo(numElements - 1);
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * Test to read data from embedded Elasticsearch instance and verify whether data is read
 * successfully.
 */
@Test
public void testHifIOWithElastic() {
  // Expected hashcode is evaluated during insertion time one time and hardcoded here.
  String expectedHashCode = "a62a85f5f081e3840baf1028d4d6c6bc";
  Configuration conf = getConfiguration();
  PCollection<KV<Text, LinkedMapWritable>> esData =
      pipeline.apply(HadoopInputFormatIO.<Text, LinkedMapWritable>read().withConfiguration(conf));
  PCollection<Long> count = esData.apply(Count.<KV<Text, LinkedMapWritable>>globally());
  // Verify that the count of objects fetched using HIFInputFormat IO is correct.
  PAssert.thatSingleton(count).isEqualTo((long) TEST_DATA_ROW_COUNT);
  PCollection<LinkedMapWritable> values = esData.apply(Values.<LinkedMapWritable>create());
  PCollection<String> textValues = values.apply(transformFunc);
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedHashCode);
  pipeline.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * This test reads data from the Elasticsearch instance and verifies whether data is read
 * successfully.
 */
@Test
public void testHifIOWithElastic() throws SecurityException, IOException {
  // Expected hashcode is evaluated during insertion time one time and hardcoded here.
  final long expectedRowCount = 1000L;
  String expectedHashCode = "42e254c8689050ed0a617ff5e80ea392";
  Configuration conf = getConfiguration(options);
  PCollection<KV<Text, LinkedMapWritable>> esData =
      pipeline.apply(HadoopInputFormatIO.<Text, LinkedMapWritable>read().withConfiguration(conf));
  // Verify that the count of objects fetched using HIFInputFormat IO is correct.
  PCollection<Long> count = esData.apply(Count.<KV<Text, LinkedMapWritable>>globally());
  PAssert.thatSingleton(count).isEqualTo(expectedRowCount);
  PCollection<LinkedMapWritable> values = esData.apply(Values.<LinkedMapWritable>create());
  PCollection<String> textValues = values.apply(transformFunc);
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedHashCode);
  pipeline.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * This test reads data from the Cassandra instance and verifies if data is read successfully.
 */
@Test
public void testHIFReadForCassandra() {
  // Expected hashcode is evaluated during insertion time one time and hardcoded here.
  String expectedHashCode = "1a30ad400afe4ebf5fde75f5d2d95408";
  Long expectedRecordsCount = 1000L;
  Configuration conf = getConfiguration(options);
  PCollection<KV<Long, String>> cassandraData = pipeline.apply(HadoopInputFormatIO
      .<Long, String>read().withConfiguration(conf).withValueTranslation(myValueTranslate));
  PAssert.thatSingleton(cassandraData.apply("Count", Count.<KV<Long, String>>globally()))
      .isEqualTo(expectedRecordsCount);
  PCollection<String> textValues = cassandraData.apply(Values.<String>create());
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedHashCode);
  pipeline.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * This test reads data from the Cassandra instance based on query and verifies if data is read
 * successfully.
 */
@Test
public void testHIFReadForCassandraQuery() {
  String expectedHashCode = "7bead6d6385c5f4dd0524720cd320b49";
  Long expectedNumRows = 1L;
  Configuration conf = getConfiguration(options);
  conf.set("cassandra.input.cql", "select * from " + CASSANDRA_KEYSPACE + "." + CASSANDRA_TABLE
      + " where token(y_id) > ? and token(y_id) <= ? "
      + "and field0 = 'user48:field0:431531'");
  PCollection<KV<Long, String>> cassandraData =
      pipeline.apply(HadoopInputFormatIO.<Long, String>read().withConfiguration(conf)
          .withValueTranslation(myValueTranslate));
  PAssert.thatSingleton(cassandraData.apply("Count", Count.<KV<Long, String>>globally()))
      .isEqualTo(expectedNumRows);
  PCollection<String> textValues = cassandraData.apply(Values.<String>create());
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedHashCode);
  pipeline.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * Test to read data from embedded Cassandra instance and verify whether data is read
 * successfully.
 * @throws Exception
 */
@Test
public void testHIFReadForCassandra() throws Exception {
  // Expected hashcode is evaluated during insertion time one time and hardcoded here.
  String expectedHashCode = "1b9780833cce000138b9afa25ba63486";
  Configuration conf = getConfiguration();
  PCollection<KV<Long, String>> cassandraData =
      p.apply(HadoopInputFormatIO.<Long, String>read().withConfiguration(conf)
          .withValueTranslation(myValueTranslate));
  // Verify the count of data retrieved from Cassandra matches expected count.
  PAssert.thatSingleton(cassandraData.apply("Count", Count.<KV<Long, String>>globally()))
      .isEqualTo(TEST_DATA_ROW_COUNT);
  PCollection<String> textValues = cassandraData.apply(Values.<String>create());
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedHashCode);
  p.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * Test to read data from embedded Cassandra instance based on query and verify whether data is
 * read successfully.
 */
@Test
public void testHIFReadForCassandraQuery() throws Exception {
  Long expectedCount = 1L;
  String expectedChecksum = "f11caabc7a9fc170e22b41218749166c";
  Configuration conf = getConfiguration();
  conf.set("cassandra.input.cql", "select * from " + CASSANDRA_KEYSPACE + "." + CASSANDRA_TABLE
      + " where token(id) > ? and token(id) <= ? and scientist='Faraday1' allow filtering");
  PCollection<KV<Long, String>> cassandraData =
      p.apply(HadoopInputFormatIO.<Long, String>read().withConfiguration(conf)
          .withValueTranslation(myValueTranslate));
  // Verify the count of data retrieved from Cassandra matches expected count.
  PAssert.thatSingleton(cassandraData.apply("Count", Count.<KV<Long, String>>globally()))
      .isEqualTo(expectedCount);
  PCollection<String> textValues = cassandraData.apply(Values.<String>create());
  // Verify the output values using checksum comparison.
  PCollection<String> consolidatedHashcode =
      textValues.apply(Combine.globally(new HashingFn()).withoutDefaults());
  PAssert.that(consolidatedHashcode).containsInAnyOrder(expectedChecksum);
  p.run().waitUntilFinish();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Test
public void testE2EBigtableRead() throws Exception {
  PipelineOptionsFactory.register(BigtableTestOptions.class);
  BigtableTestOptions options = TestPipeline.testingPipelineOptions()
      .as(BigtableTestOptions.class);

  String project = options.as(GcpOptions.class).getProject();

  BigtableOptions.Builder bigtableOptionsBuilder = new BigtableOptions.Builder()
      .setProjectId(project)
      .setInstanceId(options.getInstanceId());

  final String tableId = "BigtableReadTest";
  final long numRows = 1000L;

  Pipeline p = Pipeline.create(options);
  PCollection<Long> count = p
      .apply(BigtableIO.read().withBigtableOptions(bigtableOptionsBuilder).withTableId(tableId))
      .apply(Count.<Row>globally());
  PAssert.thatSingleton(count).isEqualTo(numRows);
  p.run();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * An end-to-end test for {@link DatastoreV1.Read#withQuery(Query)}
 *
 * <p>Write some test entities to datastore and then run a pipeline that
 * reads and counts the total number of entities. Verify that the count matches the
 * number of entities written.
 */
@Test
public void testE2EV1Read() throws Exception {
  // Read from datastore
  Query query = V1TestUtil.makeAncestorKindQuery(
      options.getKind(), options.getNamespace(), ancestor);

  DatastoreV1.Read read = DatastoreIO.v1().read()
      .withProjectId(project)
      .withQuery(query)
      .withNamespace(options.getNamespace());

  // Count the total number of entities
  Pipeline p = Pipeline.create(options);
  PCollection<Long> count = p
      .apply(read)
      .apply(Count.<Entity>globally());

  PAssert.thatSingleton(count).isEqualTo(numEntities);
  p.run();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
/**
 * An end-to-end test for {@link DatastoreV1.Read#withLiteralGqlQuery(String)}.
 *
 * <p>Write some test entities to datastore and then run a pipeline that
 * reads and counts the total number of entities. Verify that the count matches
 * the number of entities written.
 */
private void testE2EV1ReadWithGQLQuery(long limit) throws Exception {
  String gqlQuery = String.format(
      "SELECT * from %s WHERE __key__ HAS ANCESTOR KEY(%s, '%s')",
      options.getKind(), options.getKind(), ancestor);

  long expectedNumEntities = numEntities;
  if (limit > 0) {
    gqlQuery = String.format("%s LIMIT %d", gqlQuery, limit);
    expectedNumEntities = limit;
  }

  DatastoreV1.Read read = DatastoreIO.v1().read()
      .withProjectId(project)
      .withLiteralGqlQuery(gqlQuery)
      .withNamespace(options.getNamespace());

  // Count the total number of entities
  Pipeline p = Pipeline.create(options);
  PCollection<Long> count = p
      .apply(read)
      .apply(Count.<Entity>globally());

  PAssert.thatSingleton(count).isEqualTo(expectedNumEntities);
  p.run();
}
 

import org.apache.beam.sdk.transforms.Count; //导入依赖的package包/类
@Test
public void testRead() throws Exception {
  PCollection<TestRow> rows = pipeline.apply(
      JdbcIO.<TestRow>read()
          .withDataSourceConfiguration(JdbcIO.DataSourceConfiguration.create(dataSource))
          .withQuery("select name,id from " + readTableName)
          .withRowMapper(new JdbcTestHelper.CreateTestRowOfNameAndId())
          .withCoder(SerializableCoder.of(TestRow.class)));

  PAssert.thatSingleton(
      rows.apply("Count All", Count.<TestRow>globally()))
      .isEqualTo((long) EXPECTED_ROW_COUNT);

  Iterable<TestRow> expectedValues = TestRow.getExpectedValues(0, EXPECTED_ROW_COUNT);
  PAssert.that(rows).containsInAnyOrder(expectedValues);

  pipeline.run();
}