JAVA-6390: Move kafka articles from libraries-data-3 to new module

apache-kafka
2021-08-15 17:02:31 +05:30
parent f74f4508f9
commit fdc87ea6fe
4 changed files with 89 additions and 295 deletions
--- a/apache-kafka/src/test/java/com/baeldung/kafkastreams/KafkaStreamsLiveTest.java
+++ b/apache-kafka/src/test/java/com/baeldung/kafkastreams/KafkaStreamsLiveTest.java
@@ -0,0 +1,77 @@
+package com.baeldung.kafkastreams;
+
+import java.util.Arrays;
+import java.util.Properties;
+import java.util.regex.Pattern;
+
+import org.apache.kafka.clients.consumer.ConsumerConfig;
+import org.apache.kafka.common.serialization.Serdes;
+import org.apache.kafka.streams.KafkaStreams;
+import org.apache.kafka.streams.StreamsBuilder;
+import org.apache.kafka.streams.StreamsConfig;
+import org.apache.kafka.streams.Topology;
+import org.apache.kafka.streams.kstream.KStream;
+import org.apache.kafka.streams.kstream.KTable;
+import org.apache.kafka.streams.kstream.Produced;
+import org.junit.Ignore;
+import org.junit.Test;
+
+public class KafkaStreamsLiveTest {
+    private String bootstrapServers = "localhost:9092";
+
+    @Test
+    @Ignore("it needs to have kafka broker running on local")
+    public void shouldTestKafkaStreams() throws InterruptedException {
+        //given
+        String inputTopic = "inputTopic";
+
+        Properties streamsConfiguration = new Properties();
+        streamsConfiguration.put(StreamsConfig.APPLICATION_ID_CONFIG, "wordcount-live-test");
+        streamsConfiguration.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, bootstrapServers);
+        streamsConfiguration.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
+        streamsConfiguration.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
+        streamsConfiguration.put(StreamsConfig.COMMIT_INTERVAL_MS_CONFIG, 1000);
+        streamsConfiguration.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+        // Use a temporary directory for storing state, which will be automatically removed after the test.
+      //  streamsConfiguration.put(StreamsConfig.STATE_DIR_CONFIG, TestUtils.tempDirectory().getAbsolutePath());
+        
+        /*
+         * final StreamsBuilder builder = new StreamsBuilder();
+        KStream<String, String> textLines = builder.stream(wordCountTopic,
+          Consumed.with(Serdes.String(), Serdes.String()));
+
+        KTable<String, Long> wordCounts = textLines
+          .flatMapValues(value -> Arrays.asList(value.toLowerCase(Locale.ROOT)
+            .split("\\W+")))
+          .groupBy((key, word) -> word)
+          .count(Materialized.<String, Long, KeyValueStore<Bytes, byte[]>> as("counts-store"));
+         */
+        //when
+        final StreamsBuilder builder = new StreamsBuilder();
+        KStream<String, String> textLines = builder.stream(inputTopic);
+        Pattern pattern = Pattern.compile("\\W+", Pattern.UNICODE_CHARACTER_CLASS);
+
+        KTable<String, Long> wordCounts = textLines
+                .flatMapValues(value -> Arrays.asList(pattern.split(value.toLowerCase())))
+                .groupBy((key, word) -> word)
+                .count();
+
+        wordCounts.toStream().foreach((word, count) -> System.out.println("word: " + word + " -> " + count));
+
+        String outputTopic = "outputTopic";
+        //final Serde<String> stringSerde = Serdes.String();
+        //final Serde<Long> longSerde = Serdes.Long();
+        //wordCounts.toStream().to(stringSerde, longSerde, outputTopic);
+        
+        wordCounts.toStream().to("outputTopic",
+            Produced.with(Serdes.String(), Serdes.Long()));
+
+        final Topology topology = builder.build();
+        KafkaStreams streams = new KafkaStreams(topology, streamsConfiguration);
+        streams.start();
+
+        //then
+        Thread.sleep(30000);
+        streams.close();
+    }
+}