<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>de.juplo.kafka.wordcount</groupId>
- <artifactId>counter</artifactId>
+ <artifactId>top10</artifactId>
<version>1.0.0</version>
- <name>Wordcount-Counter</name>
- <description>Word-counting stream-processor of the multi-user wordcount-example</description>
+ <name>Wordcount-Top-10</name>
+ <description>Top-10 stream-processor of the multi-user wordcount-example</description>
<properties>
<docker-maven-plugin.version>0.33.0</docker-maven-plugin.version>
<java.version>11</java.version>
+++ /dev/null
-package de.juplo.kafka.wordcount.counter;
-
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
-import org.springframework.boot.context.properties.EnableConfigurationProperties;
-
-
-@SpringBootApplication
-@EnableConfigurationProperties(CounterApplicationProperties.class)
-public class CounterApplication
-{
- public static void main(String[] args)
- {
- SpringApplication.run(CounterApplication.class, args);
- }
-}
+++ /dev/null
-package de.juplo.kafka.wordcount.counter;
-
-
-import lombok.Getter;
-import lombok.Setter;
-import lombok.ToString;
-import org.springframework.boot.context.properties.ConfigurationProperties;
-
-
-@ConfigurationProperties("juplo.wordcount.counter")
-@Getter
-@Setter
-@ToString
-public class CounterApplicationProperties
-{
- private String bootstrapServer = "localhost:9092";
- private String applicationId = "counter";
- private String inputTopic = "recordings";
- private String outputTopic = "countings";
-}
+++ /dev/null
-package de.juplo.kafka.wordcount.counter;
-
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
-import lombok.extern.slf4j.Slf4j;
-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.KeyValue;
-import org.apache.kafka.streams.StreamsBuilder;
-import org.apache.kafka.streams.StreamsConfig;
-import org.apache.kafka.streams.kstream.KStream;
-import org.springframework.boot.SpringApplication;
-import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.stereotype.Component;
-
-import javax.annotation.PostConstruct;
-import javax.annotation.PreDestroy;
-import java.util.Arrays;
-import java.util.Properties;
-import java.util.concurrent.CompletableFuture;
-import java.util.regex.Pattern;
-
-import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
-
-
-@Slf4j
-@Component
-public class CounterStreamProcessor
-{
- final static Pattern PATTERN = Pattern.compile("\\W+");
-
- public final KafkaStreams streams;
-
-
- public CounterStreamProcessor(
- CounterApplicationProperties properties,
- ObjectMapper mapper,
- ConfigurableApplicationContext context)
- {
- StreamsBuilder builder = new StreamsBuilder();
-
- KStream<String, String> source = builder.stream(properties.getInputTopic());
- source
- .flatMapValues(sentence -> Arrays.asList(PATTERN.split(sentence)))
- .map((username, word) ->
- {
- try
- {
- String key = mapper.writeValueAsString(Key.of(username, word));
- return new KeyValue<>(key, word);
- }
- catch (JsonProcessingException e)
- {
- throw new RuntimeException(e);
- }
- })
- .groupByKey()
- .count()
- .mapValues(value->Long.toString(value))
- .toStream()
- .to(properties.getOutputTopic());
-
- Properties props = new Properties();
- props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
- props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
- props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
- props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
- props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
-
- streams = new KafkaStreams(builder.build(), props);
- streams.setUncaughtExceptionHandler((Throwable e) ->
- {
- log.error("Unexpected error!", e);
- CompletableFuture.runAsync(() ->
- {
- log.info("Stopping application...");
- SpringApplication.exit(context, () -> 1);
- });
- return SHUTDOWN_CLIENT;
- });
- }
-
- @PostConstruct
- public void start()
- {
- log.info("Starting Stream-Processor");
- streams.start();
- }
-
- @PreDestroy
- public void stop()
- {
- log.info("Stopping Stream-Processor");
- streams.close();
- }
-}
+++ /dev/null
-package de.juplo.kafka.wordcount.counter;
-
-import lombok.Value;
-
-
-@Value(staticConstructor = "of")
-public class Key
-{
- private final String username;
- private final String word;
-}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+import lombok.Value;
+
+
+@Value(staticConstructor = "of")
+public class Entry
+{
+ private final String word;
+ private final Long count;
+}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+import lombok.Getter;
+import lombok.Setter;
+
+
+@Getter
+@Setter
+public class Key
+{
+ private String username;
+ private String word;
+}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.List;
+
+
+@Getter
+@Setter
+public class Ranking
+{
+ private Entry[] entries = new Entry[0];
+
+ public void add(Entry newEntry)
+ {
+ if (entries.length == 0)
+ {
+ entries = new Entry[1];
+ entries[0] = newEntry;
+ return;
+ }
+
+ List<Entry> list = new LinkedList<>(Arrays.asList(entries));
+ for (int i = 0; i < list.size(); i++)
+ {
+ Entry entry;
+
+ entry = list.get(i);
+ if (entry.getCount() <= newEntry.getCount())
+ {
+ list.add(i, newEntry);
+ for (int j = i+1; j < list.size(); j++)
+ {
+ entry = list.get(j);
+ if(entry.getWord().equals(newEntry.getWord()))
+ {
+ list.remove(j);
+ break;
+ }
+ }
+ if (list.size() > 10)
+ {
+ list = list.subList(0,10);
+ }
+ entries = list.toArray(num -> new Entry[num]);
+ return;
+ }
+ }
+ }
+}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+
+
+@SpringBootApplication
+@EnableConfigurationProperties(Top10ApplicationProperties.class)
+public class Top10Application
+{
+ public static void main(String[] args)
+ {
+ SpringApplication.run(Top10Application.class, args);
+ }
+}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+
+@ConfigurationProperties("juplo.wordcount.top10")
+@Getter
+@Setter
+@ToString
+public class Top10ApplicationProperties
+{
+ private String bootstrapServer = "localhost:9092";
+ private String applicationId = "top10";
+ private String inputTopic = "countings";
+ private String outputTopic = "top10";
+}
--- /dev/null
+package de.juplo.kafka.wordcount.top10;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.slf4j.Slf4j;
+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.KeyValue;
+import org.apache.kafka.streams.StreamsBuilder;
+import org.apache.kafka.streams.StreamsConfig;
+import org.springframework.boot.SpringApplication;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.stereotype.Component;
+
+import javax.annotation.PostConstruct;
+import javax.annotation.PreDestroy;
+import java.util.Properties;
+import java.util.concurrent.CompletableFuture;
+import java.util.regex.Pattern;
+
+import static org.apache.kafka.streams.errors.StreamsUncaughtExceptionHandler.StreamThreadExceptionResponse.SHUTDOWN_CLIENT;
+
+
+@Slf4j
+@Component
+public class Top10StreamProcessor
+{
+ final static Pattern PATTERN = Pattern.compile("\\W+");
+
+ public final KafkaStreams streams;
+
+
+ public Top10StreamProcessor(
+ Top10ApplicationProperties properties,
+ ObjectMapper mapper,
+ ConfigurableApplicationContext context)
+ {
+ StreamsBuilder builder = new StreamsBuilder();
+
+ builder
+ .<String, String>stream(properties.getInputTopic())
+ .map((keyJson, countStr) ->
+ {
+ try
+ {
+ Key key = mapper.readValue(keyJson, Key.class);
+ Long count = Long.parseLong(countStr);
+ Entry entry = Entry.of(key.getWord(), count);
+ String entryJson = mapper.writeValueAsString(entry);
+ return new KeyValue<>(key.getUsername(), entryJson);
+ }
+ catch (JsonProcessingException e)
+ {
+ throw new RuntimeException(e);
+ }
+ })
+ .groupByKey()
+ .aggregate(
+ () -> "{\"entries\" : []}",
+ (username, entryJson, rankingJson) ->
+ {
+ try
+ {
+ Ranking ranking = mapper.readValue(rankingJson, Ranking.class);
+ ranking.add(mapper.readValue(entryJson, Entry.class));
+ return mapper.writeValueAsString(ranking);
+ }
+ catch (JsonProcessingException e)
+ {
+ throw new RuntimeException(e);
+ }
+ }
+ )
+ .toStream()
+ .to(properties.getOutputTopic());
+
+ Properties props = new Properties();
+ props.put(StreamsConfig.APPLICATION_ID_CONFIG, properties.getApplicationId());
+ props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, properties.getBootstrapServer());
+ props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
+ props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass().getName());
+ props.put(ConsumerConfig.AUTO_OFFSET_RESET_CONFIG, "earliest");
+
+ streams = new KafkaStreams(builder.build(), props);
+ streams.setUncaughtExceptionHandler((Throwable e) ->
+ {
+ log.error("Unexpected error!", e);
+ CompletableFuture.runAsync(() ->
+ {
+ log.info("Stopping application...");
+ SpringApplication.exit(context, () -> 1);
+ });
+ return SHUTDOWN_CLIENT;
+ });
+ }
+
+ @PostConstruct
+ public void start()
+ {
+ log.info("Starting Stream-Processor");
+ streams.start();
+ }
+
+ @PreDestroy
+ public void stop()
+ {
+ log.info("Stopping Stream-Processor");
+ streams.close();
+ }
+}
projects / demos / kafka / wordcount / commitdiff