Java KTable类代码示例

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
private KTable<K, V> doFilter(final Predicate<? super K, ? super V> predicate,
                              final StateStoreSupplier<KeyValueStore> storeSupplier,
                              boolean isFilterNot) {
    Objects.requireNonNull(predicate, "predicate can't be null");
    String name = topology.newName(FILTER_NAME);
    String internalStoreName = null;
    if (storeSupplier != null) {
        internalStoreName = storeSupplier.name();
    }
    KTableProcessorSupplier<K, V, V> processorSupplier = new KTableFilter<>(this, predicate, isFilterNot, internalStoreName);
    topology.addProcessor(name, processorSupplier, this.name);
    if (storeSupplier != null) {
        topology.addStateStore(storeSupplier, name);
    }
    return new KTableImpl<>(topology, name, processorSupplier, this.keySerde, this.valSerde, sourceNodes, internalStoreName, internalStoreName != null);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
private <V1> KTable<K, V1> doMapValues(final ValueMapper<? super V, ? extends V1> mapper,
                                       final Serde<V1> valueSerde,
                                       final StateStoreSupplier<KeyValueStore> storeSupplier) {
    Objects.requireNonNull(mapper);
    String name = topology.newName(MAPVALUES_NAME);
    String internalStoreName = null;
    if (storeSupplier != null) {
        internalStoreName = storeSupplier.name();
    }
    KTableProcessorSupplier<K, V, V1> processorSupplier = new KTableMapValues<>(this, mapper, internalStoreName);
    topology.addProcessor(name, processorSupplier, this.name);
    if (storeSupplier != null) {
        topology.addStateStore(storeSupplier, name);
        return new KTableImpl<>(topology, name, processorSupplier, this.keySerde, valueSerde, sourceNodes, internalStoreName, true);
    } else {
        return new KTableImpl<>(topology, name, processorSupplier, sourceNodes, this.queryableStoreName, false);
    }
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
public static KStreamBuilder joinTopology(KStreamBuilder builder) {
    KStream<String, Integer> kStreamA = builder.stream(stringSerde, integerSerde, INPUT_TOPIC_A);
    KStream<String, Integer> kStreamB = builder.stream(stringSerde, integerSerde, INPUT_TOPIC_B);

    KTable<String, Integer> table = kStreamA
        .groupByKey(stringSerde, integerSerde)
        .aggregate(() -> 0, (k, v, t) -> v, integerSerde, STORAGE_NAME);

    kStreamB
        .leftJoin(table, (v1, v2) -> v1 + v2, stringSerde, integerSerde)
        .to(stringSerde, integerSerde, OUTPUT_TOPIC_A);

    kStreamB
        .leftJoin(table, (v1, v2) -> v1 - v2, stringSerde, integerSerde)
        .to(stringSerde, integerSerde, OUTPUT_TOPIC_B);

    return builder;
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@SuppressWarnings("unchecked")
@Override
public <W extends Window, T> KTable<Windowed<K>, T> aggregate(final Initializer<T> initializer,
                                                              final Aggregator<? super K, ? super V, T> aggregator,
                                                              final Windows<W> windows,
                                                              final StateStoreSupplier<WindowStore> storeSupplier) {
    Objects.requireNonNull(initializer, "initializer can't be null");
    Objects.requireNonNull(aggregator, "aggregator can't be null");
    Objects.requireNonNull(windows, "windows can't be null");
    Objects.requireNonNull(storeSupplier, "storeSupplier can't be null");
    return (KTable<Windowed<K>, T>) doAggregate(
            new KStreamWindowAggregate<>(windows, storeSupplier.name(), initializer, aggregator),
            AGGREGATE_NAME,
            storeSupplier
    );
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
private <T> KTable<K, T> doAggregate(
        final KStreamAggProcessorSupplier<K, ?, V, T> aggregateSupplier,
        final String functionName,
        final StateStoreSupplier storeSupplier) {

    final String aggFunctionName = topology.newName(functionName);

    final String sourceName = repartitionIfRequired(storeSupplier.name());

    topology.addProcessor(aggFunctionName, aggregateSupplier, sourceName);
    topology.addStateStore(storeSupplier, aggFunctionName);

    return new KTableImpl<>(topology,
            aggFunctionName,
            aggregateSupplier,
            sourceName.equals(this.name) ? sourceNodes
                    : Collections.singleton(sourceName),
            storeSupplier.name(),
            isQueryable);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
private KTable<String, String> join(final KTable<String, String> first,
                                    final KTable<String, String> second,
                                    final JoinType joinType,
                                    final String queryableName) {
    final ValueJoiner<String, String, String> joiner = new ValueJoiner<String, String, String>() {
        @Override
        public String apply(final String value1, final String value2) {
            return value1 + "-" + value2;
        }
    };

    switch (joinType) {
        case INNER:
            return first.join(second, joiner, Serdes.String(), queryableName);
        case LEFT:
            return first.leftJoin(second, joiner, Serdes.String(), queryableName);
        case OUTER:
            return first.outerJoin(second, joiner, Serdes.String(), queryableName);
    }

    throw new RuntimeException("Unknown join type.");
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testJoin() throws Exception {
    final KStreamBuilder builder = new KStreamBuilder();

    final int[] expectedKeys = new int[]{0, 1, 2, 3};

    final KTable<Integer, String> table1;
    final KTable<Integer, String> table2;
    final KTable<Integer, String> joined;
    final MockProcessorSupplier<Integer, String> processor;

    processor = new MockProcessorSupplier<>();
    table1 = builder.table(intSerde, stringSerde, topic1, storeName1);
    table2 = builder.table(intSerde, stringSerde, topic2, storeName2);
    joined = table1.join(table2, MockValueJoiner.TOSTRING_JOINER);
    joined.toStream().process(processor);

    doTestJoin(builder, expectedKeys, processor, joined);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testNotSendingOldValues() throws Exception {
    final KStreamBuilder builder = new KStreamBuilder();

    final int[] expectedKeys = new int[]{0, 1, 2, 3};

    final KTable<Integer, String> table1;
    final KTable<Integer, String> table2;
    final KTable<Integer, String> joined;
    final MockProcessorSupplier<Integer, String> proc;

    table1 = builder.table(intSerde, stringSerde, topic1, storeName1);
    table2 = builder.table(intSerde, stringSerde, topic2, storeName2);
    joined = table1.join(table2, MockValueJoiner.TOSTRING_JOINER);
    proc = new MockProcessorSupplier<>();
    builder.addProcessor("proc", proc, ((KTableImpl<?, ?, ?>) joined).name);

    doTestSendingOldValues(builder, expectedKeys, table1, table2, proc, joined, false);

}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testQueryableNotSendingOldValues() throws Exception {
    final KStreamBuilder builder = new KStreamBuilder();

    final int[] expectedKeys = new int[]{0, 1, 2, 3};

    final KTable<Integer, String> table1;
    final KTable<Integer, String> table2;
    final KTable<Integer, String> joined;
    final MockProcessorSupplier<Integer, String> proc;

    table1 = builder.table(intSerde, stringSerde, topic1, storeName1);
    table2 = builder.table(intSerde, stringSerde, topic2, storeName2);
    joined = table1.join(table2, MockValueJoiner.TOSTRING_JOINER, Serdes.String(), "anyQueryableName");
    proc = new MockProcessorSupplier<>();
    builder.addProcessor("proc", proc, ((KTableImpl<?, ?, ?>) joined).name);

    doTestSendingOldValues(builder, expectedKeys, table1, table2, proc, joined, false);

}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testSendingOldValues() throws Exception {
    final KStreamBuilder builder = new KStreamBuilder();

    final int[] expectedKeys = new int[]{0, 1, 2, 3};

    final KTable<Integer, String> table1;
    final KTable<Integer, String> table2;
    final KTable<Integer, String> joined;
    final MockProcessorSupplier<Integer, String> proc;

    table1 = builder.table(intSerde, stringSerde, topic1, storeName1);
    table2 = builder.table(intSerde, stringSerde, topic2, storeName2);
    joined = table1.join(table2, MockValueJoiner.TOSTRING_JOINER);

    proc = new MockProcessorSupplier<>();
    builder.addProcessor("proc", proc, ((KTableImpl<?, ?, ?>) joined).name);

    doTestSendingOldValues(builder, expectedKeys, table1, table2, proc, joined, true);

}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testKTable() {
    final KStreamBuilder builder = new KStreamBuilder();

    String topic1 = "topic1";

    KTable<String, Integer> table1 = builder.table(stringSerde, intSerde, topic1, "anyStoreName");

    MockProcessorSupplier<String, Integer> proc1 = new MockProcessorSupplier<>();
    table1.toStream().process(proc1);

    driver = new KStreamTestDriver(builder, stateDir);
    driver.process(topic1, "A", 1);
    driver.process(topic1, "B", 2);
    driver.process(topic1, "C", 3);
    driver.process(topic1, "D", 4);
    driver.flushState();
    driver.process(topic1, "A", null);
    driver.process(topic1, "B", null);
    driver.flushState();

    assertEquals(Utils.mkList("A:1", "B:2", "C:3", "D:4", "A:null", "B:null"), proc1.processed);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testKTable() {
    final KStreamBuilder builder = new KStreamBuilder();

    String topic1 = "topic1";

    KTable<String, String> table1 = builder.table(stringSerde, stringSerde, topic1, "anyStoreName");
    KTable<String, Integer> table2 = table1.mapValues(new ValueMapper<CharSequence, Integer>() {
        @Override
        public Integer apply(CharSequence value) {
            return value.charAt(0) - 48;
        }
    });

    MockProcessorSupplier<String, Integer> proc2 = new MockProcessorSupplier<>();
    table2.toStream().process(proc2);

    doTestKTable(builder, topic1, proc2);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void testQueryableKTable() {
    final KStreamBuilder builder = new KStreamBuilder();

    String topic1 = "topic1";

    KTable<String, String> table1 = builder.table(stringSerde, stringSerde, topic1, "anyStoreName");
    KTable<String, Integer> table2 = table1.mapValues(new ValueMapper<CharSequence, Integer>() {
        @Override
        public Integer apply(CharSequence value) {
            return value.charAt(0) - 48;
        }
    }, Serdes.Integer(), "anyName");

    MockProcessorSupplier<String, Integer> proc2 = new MockProcessorSupplier<>();
    table2.toStream().process(proc2);

    doTestKTable(builder, topic1, proc2);
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void shouldCountSessionWindowsWithInternalStoreName() throws Exception {
    final Map<Windowed<String>, Long> results = new HashMap<>();
    KTable table = groupedStream.count(SessionWindows.with(30));
    table.foreach(new ForeachAction<Windowed<String>, Long>() {
        @Override
        public void apply(final Windowed<String> key, final Long value) {
            results.put(key, value);
        }
    });
    doCountSessionWindows(results);
    assertNull(table.queryableStoreName());
}
 

import org.apache.kafka.streams.kstream.KTable; //导入依赖的package包/类
@Test
public void shouldReduceSessionWindows() throws Exception {
    final Map<Windowed<String>, String> results = new HashMap<>();
    KTable table = groupedStream.reduce(
            new Reducer<String>() {
                @Override
                public String apply(final String value1, final String value2) {
                    return value1 + ":" + value2;
                }
            }, SessionWindows.with(30),
            "session-store");
    table.foreach(new ForeachAction<Windowed<String>, String>() {
        @Override
        public void apply(final Windowed<String> key, final String value) {
            results.put(key, value);
        }
    });
    doReduceSessionWindows(results);
    assertEquals(table.queryableStoreName(), "session-store");
}