fix: close running scheduledExecutor when closing client

Author: ptitFicus

src/main/java/fr/maif/IzanamiClient.java

@@ -92,11 +92,7 @@ public IzanamiClient(
      * @return a CompletableFuture that complete when SSE client is closed, or immediately if there is no SSE client
      */
     public CompletableFuture<Void> close() {
-        if(this.featureService instanceof SSEFeatureService) {
-            return ((SSEFeatureService)this.featureService).disconnect();
-        } else {
-            return CompletableFuture.completedFuture(null);
-        }
+        return this.featureService.disconnect();
     }
 
     /**

src/main/java/fr/maif/requests/FeatureService.java

@@ -10,6 +10,7 @@
 
 public interface FeatureService {
     ClientConfiguration configuration();
+    CompletableFuture<Void> disconnect();
 
     @Deprecated
     default CompletableFuture<Map<String, Boolean>> featureStates(

src/main/java/fr/maif/requests/FetchFeatureService.java

@@ -16,10 +16,7 @@
 import org.slf4j.LoggerFactory;
 
 import java.util.*;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
+import java.util.concurrent.*;
 import java.util.stream.Collectors;
 
 import static fr.maif.requests.FeatureRequest.newFeatureRequest;
@@ -29,6 +26,7 @@ public class FetchFeatureService implements FeatureService {
     protected ClientConfiguration configuration;
     private static final Logger LOGGER = LoggerFactory.getLogger(FetchFeatureService.class);
     private final Cache<String, Feature<?>> cache;
+    private final Optional<ScheduledExecutorService> refreshScheduler;
 
     public FetchFeatureService(ClientConfiguration configuration) {
         this.configuration = configuration;
@@ -37,12 +35,15 @@ public FetchFeatureService(ClientConfiguration configuration) {
 
 
         if(configuration.cacheConfiguration.enabled) {
-            ScheduledExecutorService scheduler = Executors.newScheduledThreadPool(1);
+            var scheduler = Executors.newScheduledThreadPool(1);
             scheduler.scheduleAtFixedRate(
                     this::refreshCache,
                     0,
                     configuration.cacheConfiguration.refreshInterval.getSeconds(), TimeUnit.SECONDS
             );
+            refreshScheduler = Optional.of(scheduler);
+        } else {
+            refreshScheduler = Optional.empty();
         }
     }
 
@@ -76,6 +77,12 @@ public ClientConfiguration configuration() {
         return configuration;
     }
 
+    @Override
+    public CompletableFuture<Void> disconnect() {
+        refreshScheduler.ifPresent(ExecutorService::shutdown);
+        return CompletableFuture.completedFuture(null);
+    }
+
     @Override
     public CompletableFuture<IzanamiResult> featureValues(FeatureRequest request) {
         LOGGER.debug("Feature activation request for {}", String.join(",", request.features.keySet()));

src/main/java/fr/maif/requests/SSEFeatureService.java

@@ -56,6 +56,7 @@ private void processEvent(IzanamiEvent event) {
         }
     }
 
+    @Override
     public CompletableFuture<Void> disconnect() {
         return this.sseClient.close();
     }