Die Implementierung speichert Zustand & Offsets vor _jedem_ `poll()`

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

diff --git a/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java b/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java
index 5e1a12c..86fe68a 100644 (file)
--- a/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java
+++ b/src/main/java/de/juplo/kafka/ApplicationRebalanceListener.java
@@ -2,7 +2,6 @@ package de.juplo.kafka;
 
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
-import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
 import org.apache.kafka.common.TopicPartition;
 
 import java.util.*;
@@ -10,7 +9,7 @@ import java.util.*;
 
 @RequiredArgsConstructor
 @Slf4j
-public class ApplicationRebalanceListener implements ConsumerRebalanceListener
+public class ApplicationRebalanceListener implements RebalanceListener
 {
   private final ApplicationRecordHandler recordHandler;
   private final AdderResults adderResults;
@@ -82,4 +81,37 @@ public class ApplicationRebalanceListener implements ConsumerRebalanceListener
           state.getOffset()));
     });
   }
+
+  @Override
+  public void beforeNextPoll()
+  {
+    partitions
+      .stream()
+      .forEach(partition ->
+      {
+        log.info("{} - persisting state & offset for partition: {}", id, partition);
+        ApplicationState state = recordHandler.getState(partition);
+        log.info(
+          "{} - offset of next unseen message for partition {} is {}",
+          id,
+          partition,
+          state.getOffset());
+        for (String user : state.getAdderState().keySet())
+        {
+          log.info(
+            "{} - Saved state for partition={}|user={}: {}",
+            id,
+            partition,
+            user,
+            state.getAdderState().get(user));
+        }
+        Map<String, List<AdderResult>> results = adderResults.getState(partition);
+        stateRepository.save(
+          new StateDocument(
+            partition,
+            state.getAdderState(),
+            results,
+            state.getOffset()));
+      });
+  }
 }