Verbesserungen aus 'stored-state' nach 'rebalance-listener' gemerged

[demos/kafka/training] / src / main / java / de / juplo / kafka / KeyCountingRecordHandler.java

diff --git a/src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java b/src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java
new file mode 100644 (file)
index 0000000..099dcf7
--- /dev/null
+++ b/src/main/java/de/juplo/kafka/KeyCountingRecordHandler.java
@@ -0,0 +1,46 @@
+package de.juplo.kafka;
+
+import lombok.extern.slf4j.Slf4j;
+import org.apache.kafka.clients.consumer.ConsumerRecord;
+
+import java.util.HashMap;
+import java.util.Map;
+
+
+@Slf4j
+public class KeyCountingRecordHandler implements RecordHandler<String, Long>
+{
+  private final Map<Integer, Map<String, Long>> seen = new HashMap<>();
+
+
+  @Override
+  public void accept(ConsumerRecord<String, Long> record)
+  {
+    Integer partition = record.partition();
+    String key = record.key() == null ? "NULL" : record.key().toString();
+    Map<String, Long> byKey = seen.get(partition);
+
+    if (!byKey.containsKey(key))
+      byKey.put(key, 0l);
+
+    long seenByKey = byKey.get(key);
+    seenByKey++;
+    byKey.put(key, seenByKey);
+  }
+
+  public void addPartition(Integer partition, Map<String, Long> statistics)
+  {
+    seen.put(partition, statistics);
+  }
+
+  public Map<String, Long> removePartition(Integer partition)
+  {
+    return seen.remove(partition);
+  }
+
+
+  public Map<Integer, Map<String, Long>> getSeen()
+  {
+    return seen;
+  }
+}