Für null-Keys wird der String NULL gezählt

diff --git a/src/main/java/de/juplo/kafka/EndlessConsumer.java b/src/main/java/de/juplo/kafka/EndlessConsumer.java
index 063a09e..127c3d3 100644 (file)
--- a/src/main/java/de/juplo/kafka/EndlessConsumer.java
+++ b/src/main/java/de/juplo/kafka/EndlessConsumer.java
@@ -94,7 +94,7 @@ public class EndlessConsumer implements Runnable
           );
 
           Integer partition = record.partition();
-          String key = record.key();
+          String key = record.key() == null ? "NULL" : record.key();
 
           if (!seen.containsKey(partition))
             seen.put(partition, new HashMap<>());