Unify on Set.of

5 files changed, 12 insertions, 21 deletions

diff --git a/container-core/src/main/java/com/yahoo/container/di/ConfigRetriever.java b/container-core/src/main/java/com/yahoo/container/di/ConfigRetriever.java
index fcccc02d143..5a04bd8eae1 100644
--- a/container-core/src/main/java/com/yahoo/container/di/ConfigRetriever.java
+++ b/container-core/src/main/java/com/yahoo/container/di/ConfigRetriever.java
@@ -8,7 +8,6 @@ import com.yahoo.container.di.config.Subscriber;
 import com.yahoo.container.di.config.SubscriberFactory;
 import com.yahoo.vespa.config.ConfigKey;
 
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Optional;
@@ -135,7 +134,7 @@ public final class ConfigRetriever {
 
     private void resetComponentSubscriberIfBootstrap(ConfigSnapshot configSnapshot) {
         if (configSnapshot instanceof BootstrapConfigs) {
-            setupComponentSubscriber(Collections.emptySet());
+            setupComponentSubscriber(Set.of());
         }
     }
 
diff --git a/container-core/src/main/java/com/yahoo/container/di/Osgi.java b/container-core/src/main/java/com/yahoo/container/di/Osgi.java
index 0ff640031fc..7bab8605a3e 100644
--- a/container-core/src/main/java/com/yahoo/container/di/Osgi.java
+++ b/container-core/src/main/java/com/yahoo/container/di/Osgi.java
@@ -10,8 +10,6 @@ import org.osgi.framework.Bundle;
 import java.util.Collection;
 import java.util.Set;
 
-import static java.util.Collections.emptySet;
-
 /**
  * This interface has default implementations of all methods, to allow using it
  * for testing, instead of mocking or a test implementation.
@@ -49,7 +47,7 @@ public interface Osgi {
      * @return The set of bundles that are no longer needed by the new or latest good generation.
      */
     default Set<Bundle> completeBundleGeneration(GenerationStatus status) {
-        return emptySet();
+        return Set.of();
     }
 
     default Class<?> resolveClass(BundleInstantiationSpecification spec) {
diff --git a/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/ComponentRegistryNode.java b/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/ComponentRegistryNode.java
index ca10072c6c9..8b5fb128e2b 100644
--- a/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/ComponentRegistryNode.java
+++ b/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/ComponentRegistryNode.java
@@ -8,10 +8,8 @@ import com.yahoo.component.provider.ComponentRegistry;
 import com.yahoo.config.ConfigInstance;
 import com.yahoo.vespa.config.ConfigKey;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
-import java.util.stream.Collectors;
 
 /**
  * @author Tony Vaagenes
@@ -20,7 +18,7 @@ import java.util.stream.Collectors;
  */
 public class ComponentRegistryNode extends Node {
 
-    private static ComponentId componentRegistryNamespace = ComponentId.fromString("ComponentRegistry");
+    private static final ComponentId componentRegistryNamespace = ComponentId.fromString("ComponentRegistry");
 
     private final Class<?> componentClass;
 
@@ -63,7 +61,7 @@ public class ComponentRegistryNode extends Node {
 
     @Override
     public Set<ConfigKey<ConfigInstance>> configKeys() {
-        return Collections.emptySet();
+        return Set.of();
     }
 
     @Override
@@ -76,8 +74,7 @@ public class ComponentRegistryNode extends Node {
 
     @Override
     public boolean equals(Object other) {
-        if (other instanceof ComponentRegistryNode) {
-            ComponentRegistryNode that = (ComponentRegistryNode) other;
+        if (other instanceof ComponentRegistryNode that) {
             return this.componentId().equals(that.componentId()) && this.instanceType().equals(that.instanceType())
                     && equalNodeEdges(this.usedComponents(), that.usedComponents());
         } else {
diff --git a/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/GuiceNode.java b/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/GuiceNode.java
index 936eadb0b3c..8e6a39a4921 100644
--- a/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/GuiceNode.java
+++ b/container-core/src/main/java/com/yahoo/container/di/componentgraph/core/GuiceNode.java
@@ -7,7 +7,6 @@ import com.yahoo.config.ConfigInstance;
 import com.yahoo.vespa.config.ConfigKey;
 
 import java.lang.annotation.Annotation;
-import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 
@@ -24,8 +23,7 @@ public final class GuiceNode extends Node {
     private final Object myInstance;
     private final Annotation annotation;
 
-    public GuiceNode(Object myInstance,
-                     Annotation annotation) {
+    public GuiceNode(Object myInstance, Annotation annotation) {
         super(componentId(myInstance));
         this.myInstance = myInstance;
         this.annotation = annotation;
@@ -33,7 +31,7 @@ public final class GuiceNode extends Node {
 
     @Override
     public Set<ConfigKey<ConfigInstance>> configKeys() {
-        return Collections.emptySet();
+        return Set.of();
     }
 
     @Override
@@ -54,7 +52,7 @@ public final class GuiceNode extends Node {
 
     @Override
     public List<Node> usedComponents() {
-        return Collections.emptyList();
+        return List.of();
     }
 
     @Override
diff --git a/container-core/src/main/java/com/yahoo/container/jdisc/state/MetricsPacketsHandler.java b/container-core/src/main/java/com/yahoo/container/jdisc/state/MetricsPacketsHandler.java
index 165330662a9..894a231f9be 100644
--- a/container-core/src/main/java/com/yahoo/container/jdisc/state/MetricsPacketsHandler.java
+++ b/container-core/src/main/java/com/yahoo/container/jdisc/state/MetricsPacketsHandler.java
@@ -25,7 +25,6 @@ import java.nio.ByteBuffer;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -91,7 +90,7 @@ public class MetricsPacketsHandler extends AbstractRequestHandler {
 
             @Override
             protected Iterable<ByteBuffer> responseContent() {
-                return Collections.singleton(ByteBuffer.wrap(buildMetricOutput(request.getUri().getQuery())));
+                return Set.of(ByteBuffer.wrap(buildMetricOutput(request.getUri().getQuery())));
             }
         }.dispatch(handler);
 
@@ -160,7 +159,7 @@ public class MetricsPacketsHandler extends AbstractRequestHandler {
     }
 
     private List<JsonNode> getPacketsForSnapshot(MetricSnapshot metricSnapshot, String application, long timestamp) {
-        if (metricSnapshot == null) return Collections.emptyList();
+        if (metricSnapshot == null) return List.of();
 
         List<JsonNode> packets = new ArrayList<>();
 
@@ -178,9 +177,9 @@ public class MetricsPacketsHandler extends AbstractRequestHandler {
     }
 
     private List<JsonNode> getPacketsForSnapshot(MetricSnapshot metricSnapshot, String metricSetId, String application, long timestamp) {
-        if (metricSnapshot == null) return Collections.emptyList();
+        if (metricSnapshot == null) return List.of();
         if (metricSetId == null) return getPacketsForSnapshot(metricSnapshot, application, timestamp);
-        Set<String> configuredMetrics = metricSets.getOrDefault(metricSetId, Collections.emptySet());
+        Set<String> configuredMetrics = metricSets.getOrDefault(metricSetId, Set.of());
         List<JsonNode> packets = new ArrayList<>();
 
         for (Map.Entry<MetricDimensions, MetricSet> snapshotEntry : metricSnapshot) {