Java ValueTransformerSupplier类代码示例

import org.apache.kafka.streams.kstream.ValueTransformerSupplier; //导入依赖的package包/类
@Override
public <V1> KStream<K, V1> transformValues(ValueTransformerSupplier<? super V, ? extends V1> valueTransformerSupplier, String... stateStoreNames) {
    Objects.requireNonNull(valueTransformerSupplier, "valueTransformSupplier can't be null");
    String name = topology.newName(TRANSFORMVALUES_NAME);

    topology.addProcessor(name, new KStreamTransformValues<>(valueTransformerSupplier), this.name);
    topology.connectProcessorAndStateStores(name, stateStoreNames);

    return new KStreamImpl<>(topology, name, sourceNodes, this.repartitionRequired);
}
 

import org.apache.kafka.streams.kstream.ValueTransformerSupplier; //导入依赖的package包/类
public KStreamTransformValues(ValueTransformerSupplier<V, R> valueTransformerSupplier) {
    this.valueTransformerSupplier = valueTransformerSupplier;
}
 

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

    ValueTransformerSupplier<Number, Integer> valueTransformerSupplier =
        new ValueTransformerSupplier<Number, Integer>() {
            public ValueTransformer<Number, Integer> get() {
                return new ValueTransformer<Number, Integer>() {

                    private int total = 0;

                    @Override
                    public void init(ProcessorContext context) {
                    }

                    @Override
                    public Integer transform(Number value) {
                        total += value.intValue();
                        return total;
                    }

                    @Override
                    public Integer punctuate(long timestamp) {
                        return null;
                    }

                    @Override
                    public void close() {
                    }
                };
            }
        };

    final int[] expectedKeys = {1, 10, 100, 1000};

    KStream<Integer, Integer> stream;
    MockProcessorSupplier<Integer, Integer> processor = new MockProcessorSupplier<>();
    stream = builder.stream(intSerde, intSerde, topicName);
    stream.transformValues(valueTransformerSupplier).process(processor);

    driver = new KStreamTestDriver(builder);
    for (int expectedKey : expectedKeys) {
        driver.process(topicName, expectedKey, expectedKey * 10);
    }

    assertEquals(4, processor.processed.size());

    String[] expected = {"1:10", "10:110", "100:1110", "1000:11110"};

    for (int i = 0; i < expected.length; i++) {
        assertEquals(expected[i], processor.processed.get(i));
    }
}
 

import org.apache.kafka.streams.kstream.ValueTransformerSupplier; //导入依赖的package包/类
/**
 * @param <R>
 * @param valueTransformerSupplier
 * @param stateStoreNames
 * @return
 * @see org.apache.kafka.streams.kstream.KStream#transformValues(org.apache.kafka.streams.kstream.ValueTransformerSupplier, java.lang.String[])
 */
public <R> KStream<K, R> transformValues(ValueTransformerSupplier<V, R> valueTransformerSupplier,
		String... stateStoreNames) {
	return delegate.transformValues(valueTransformerSupplier, stateStoreNames);
}