Unify on Map.of

10 files changed, 24 insertions, 35 deletions

diff --git a/container-search/src/main/java/com/yahoo/search/pagetemplates/config/PageTemplateXMLReader.java b/container-search/src/main/java/com/yahoo/search/pagetemplates/config/PageTemplateXMLReader.java
index f59124e293e..7b969404984 100644
--- a/container-search/src/main/java/com/yahoo/search/pagetemplates/config/PageTemplateXMLReader.java
+++ b/container-search/src/main/java/com/yahoo/search/pagetemplates/config/PageTemplateXMLReader.java
@@ -331,7 +331,7 @@ public class PageTemplateXMLReader {
 
     private Map<String,String> readParameters(Element containingElement) {
         List<Element> parameterElements=XML.getChildren(containingElement,"parameter");
-        if (parameterElements.size()==0) return Collections.emptyMap(); // Shortcut
+        if (parameterElements.size()==0) return Map.of(); // Shortcut
 
         Map<String,String> parameters=new LinkedHashMap<>();
         for (Element parameter : parameterElements) {
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/CopyOnWriteContent.java b/container-search/src/main/java/com/yahoo/search/query/profile/CopyOnWriteContent.java
index 53f8ccbe6de..3587175b671 100644
--- a/container-search/src/main/java/com/yahoo/search/query/profile/CopyOnWriteContent.java
+++ b/container-search/src/main/java/com/yahoo/search/query/profile/CopyOnWriteContent.java
@@ -66,7 +66,7 @@ public class CopyOnWriteContent extends FreezableClass implements Cloneable {
     public void freeze() {
         // Freeze this
         if (unmodifiableMap==null)
-            unmodifiableMap= map!=null ? Collections.unmodifiableMap(map) : Collections.<String, Object>emptyMap();
+            unmodifiableMap= map!=null ? Collections.unmodifiableMap(map) : Map.of();
         map=null; // just to keep the states simpler
 
         // Freeze content
@@ -119,7 +119,7 @@ public class CopyOnWriteContent extends FreezableClass implements Cloneable {
     //------- Content access -------------------------------------------------------
 
     public Map<String,Object> unmodifiableMap() {
-        if (isEmpty()) return Collections.emptyMap();
+        if (isEmpty()) return Map.of();
         if (map==null) // in COPYONWRITE or FROZEN state
             return unmodifiableMap;
         // In WRITABLE state: Create unmodifiable wrapper if necessary and return it
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileProperties.java b/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileProperties.java
index 8778dcc7348..261e42a972d 100644
--- a/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileProperties.java
+++ b/container-search/src/main/java/com/yahoo/search/query/profile/QueryProfileProperties.java
@@ -18,7 +18,6 @@ import com.yahoo.search.query.profile.types.QueryProfileType;
 import com.yahoo.tensor.Tensor;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -127,7 +126,7 @@ public class QueryProfileProperties extends Properties {
             name = unalias(name, context);
 
             if (context == null)
-                context = Collections.emptyMap();
+                context = Map.of();
 
             if ( ! profile.isOverridable(name, context)) return;
 
@@ -237,7 +236,7 @@ public class QueryProfileProperties extends Properties {
         context = contextWithZoneInfo(context);
 
         path = unalias(path, context);
-        if (context == null) context = Collections.emptyMap();
+        if (context == null) context = Map.of();
 
         Map<String, Object> properties = new HashMap<>();
         for (var entry : profile.listValues(path, context, substitution).entrySet()) {
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/compiled/CompiledQueryProfile.java b/container-search/src/main/java/com/yahoo/search/query/profile/compiled/CompiledQueryProfile.java
index 4b3c3ede1e9..562d59846d1 100644
--- a/container-search/src/main/java/com/yahoo/search/query/profile/compiled/CompiledQueryProfile.java
+++ b/container-search/src/main/java/com/yahoo/search/query/profile/compiled/CompiledQueryProfile.java
@@ -9,7 +9,6 @@ import com.yahoo.search.query.profile.QueryProfileProperties;
 import com.yahoo.search.query.profile.SubstituteString;
 import com.yahoo.search.query.profile.types.QueryProfileType;
 
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.regex.Matcher;
@@ -102,7 +101,7 @@ public class CompiledQueryProfile extends AbstractComponent implements Cloneable
      * For example, if {a.d =&gt; "a.d-value" ,a.e =&gt; "a.e-value", b.d =&gt; "b.d-value", then calling listValues("a")
      * will return {"d" =&gt; "a.d-value","e" =&gt; "a.e-value"}
      */
-    public final Map<String, Object> listValues(CompoundName prefix) {  return listValues(prefix, Collections.emptyMap()); }
+    public final Map<String, Object> listValues(CompoundName prefix) {  return listValues(prefix, Map.of()); }
     public final Map<String, Object> listValues(String prefix) { return listValues(new CompoundName(prefix)); }
 
     /**
diff --git a/container-search/src/main/java/com/yahoo/search/query/profile/compiled/DimensionalValue.java b/container-search/src/main/java/com/yahoo/search/query/profile/compiled/DimensionalValue.java
index b6fa58628a1..0823989a104 100644
--- a/container-search/src/main/java/com/yahoo/search/query/profile/compiled/DimensionalValue.java
+++ b/container-search/src/main/java/com/yahoo/search/query/profile/compiled/DimensionalValue.java
@@ -2,18 +2,15 @@
 package com.yahoo.search.query.profile.compiled;
 
 import com.yahoo.processing.request.CompoundName;
-import com.yahoo.search.query.profile.DimensionBinding;
 import com.yahoo.search.query.profile.SubstituteString;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.HashMap;
-import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
-import java.util.Set;
 
 /**
  * Contains the values a given key in a DimensionalMap may take for different dimensional contexts.
@@ -44,7 +41,7 @@ public class DimensionalValue<VALUE> {
     /** Returns the value matching this context, or null if none */
     public VALUE get(Map<String, String> context) {
         if (context == null)
-            context = Collections.emptyMap();
+            context = Map.of();
 
         for (BindingSpec spec : bindingSpecs) {
             if ( ! spec.matches(context)) continue;
@@ -156,8 +153,7 @@ public class DimensionalValue<VALUE> {
                 variants.add(binding);
 
                 // We're combining values for efficiency, so remove incorrect provenance info
-                if (value instanceof ValueWithSource) {
-                    ValueWithSource v1 = (ValueWithSource)value;
+                if (value instanceof ValueWithSource v1) {
                     ValueWithSource v2 = (ValueWithSource)newValue;
 
                     if (v1.source() != null && ! v1.source().equals(v2.source()))
@@ -220,14 +216,12 @@ public class DimensionalValue<VALUE> {
             private VALUE substituteIfRelative(VALUE value,
                                                Binding variant,
                                                Map<CompoundName, DimensionalValue.Builder<VALUE>> entries) {
-                if (value instanceof ValueWithSource && ((ValueWithSource)value).value() instanceof SubstituteString) {
-                    ValueWithSource valueWithSource = (ValueWithSource)value;
+                if (value instanceof ValueWithSource valueWithSource && ((ValueWithSource)value).value() instanceof SubstituteString) {
                     SubstituteString substitute = (SubstituteString)valueWithSource.value();
                     if (substitute.hasRelative()) {
                         List<SubstituteString.Component> resolvedComponents = new ArrayList<>(substitute.components().size());
                         for (SubstituteString.Component component : substitute.components()) {
-                            if (component instanceof SubstituteString.RelativePropertyComponent) {
-                                SubstituteString.RelativePropertyComponent relativeComponent = (SubstituteString.RelativePropertyComponent)component;
+                            if (component instanceof SubstituteString.RelativePropertyComponent relativeComponent) {
                                 var substituteValues = lookupByLocalName(relativeComponent.fieldName(), entries);
                                 if (substituteValues == null)
                                     throw new IllegalArgumentException("Could not resolve local substitution '" +
@@ -274,8 +268,8 @@ public class DimensionalValue<VALUE> {
 
         /** Returns whether this context contains all the keys of this */
         public boolean matches(Map<String, String> context) {
-            for (int i = 0; i < dimensions.length; i++)
-                if ( ! context.containsKey(dimensions[i])) return false;
+            for (String dimension : dimensions)
+                if (!context.containsKey(dimension)) return false;
             return true;
         }
 
diff --git a/container-search/src/main/java/com/yahoo/search/query/textserialize/item/ItemArguments.java b/container-search/src/main/java/com/yahoo/search/query/textserialize/item/ItemArguments.java
index 080f938d61a..e5319b50b4f 100644
--- a/container-search/src/main/java/com/yahoo/search/query/textserialize/item/ItemArguments.java
+++ b/container-search/src/main/java/com/yahoo/search/query/textserialize/item/ItemArguments.java
@@ -1,7 +1,6 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.search.query.textserialize.item;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -19,7 +18,7 @@ public class ItemArguments {
             properties = (Map<?, ?>) ListUtil.first(arguments);
             children = ListUtil.rest(arguments);
         } else {
-            properties = Collections.emptyMap();
+            properties = Map.of();
             children = arguments;
         }
     }
diff --git a/container-search/src/main/java/com/yahoo/search/result/Hit.java b/container-search/src/main/java/com/yahoo/search/result/Hit.java
index d81880cc548..045388ba31c 100644
--- a/container-search/src/main/java/com/yahoo/search/result/Hit.java
+++ b/container-search/src/main/java/com/yahoo/search/result/Hit.java
@@ -333,7 +333,7 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
      */
     public void setFillable() {
         if (filled == null) {
-            filled = Collections.emptySet();
+            filled = Set.of();
             unmodifiableFilled = filled;
         }
     }
@@ -347,7 +347,7 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
      */
     public void setFilled(String summaryClass) {
         if (filled == null || filled.isEmpty()) {
-            filled = Collections.singleton(summaryClass);
+            filled = Set.of(summaryClass);
             unmodifiableFilled = filled;
         } else if (filled.size() == 1) {
             filled = new HashSet<>(filled);
@@ -483,7 +483,7 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
     private Map<String, Object> getUnmodifiableFieldMap() {
         if (unmodifiableFieldMap == null) {
             if (fields == null) {
-                return Collections.emptyMap();
+                return Map.of();
             } else {
                 unmodifiableFieldMap = Collections.unmodifiableMap(fields);
             }
@@ -574,12 +574,12 @@ public class Hit extends ListenableFreezableClass implements Data, Comparable<Hi
     /** Attach some data to this hit for this searcher */
     public void setSearcherSpecificMetaData(Searcher searcher, Object data) {
         if (searcherSpecificMetaData == null) {
-            searcherSpecificMetaData = Collections.singletonMap(searcher, data);
+            searcherSpecificMetaData = Map.of(searcher, data);
         } else {
             if (searcherSpecificMetaData.size() == 1) {
                 Object tmp = searcherSpecificMetaData.get(searcher);
                 if (tmp != null) {
-                    searcherSpecificMetaData = Collections.singletonMap(searcher, data);
+                    searcherSpecificMetaData = Map.of(searcher, data);
                 } else {
                     searcherSpecificMetaData = new TreeMap<>(searcherSpecificMetaData);
                     searcherSpecificMetaData.put(searcher, data);
diff --git a/container-search/src/main/java/com/yahoo/search/yql/YqlParser.java b/container-search/src/main/java/com/yahoo/search/yql/YqlParser.java
index 7ae02c18e7a..e66cac5766c 100644
--- a/container-search/src/main/java/com/yahoo/search/yql/YqlParser.java
+++ b/container-search/src/main/java/com/yahoo/search/yql/YqlParser.java
@@ -913,7 +913,7 @@ public class YqlParser implements Parser {
             GroupingOperation groupingOperation = GroupingOperation.fromString(groupingAst.getArgument(0));
             VespaGroupingStep groupingStep = new VespaGroupingStep(groupingOperation);
             List<Object> continuations = getAnnotation(groupingAst, "continuations", List.class,
-                                                       Collections.emptyList(), "grouping continuations");
+                                                       List.of(), "grouping continuations");
 
             for (Object continuation : continuations) {
                 groupingStep.continuations().add(Continuation.fromString(dereference(continuation)));
@@ -1614,7 +1614,7 @@ public class YqlParser implements Parser {
         {
             Item leaf = (Item) out;
             Map<?, ?> itemAnnotations = getAnnotation(ast, ANNOTATIONS,
-                                                      Map.class, Collections.emptyMap(), "item annotation map");
+                                                      Map.class, Map.of(), "item annotation map");
             for (Map.Entry<?, ?> entry : itemAnnotations.entrySet()) {
                 Preconditions.checkArgument(entry.getKey() instanceof String,
                                             "Expected String annotation key, got %s.", entry.getKey().getClass());
diff --git a/container-search/src/main/java/com/yahoo/text/interpretation/Annotations.java b/container-search/src/main/java/com/yahoo/text/interpretation/Annotations.java
index 561d2bf34d0..c957432a957 100644
--- a/container-search/src/main/java/com/yahoo/text/interpretation/Annotations.java
+++ b/container-search/src/main/java/com/yahoo/text/interpretation/Annotations.java
@@ -1,7 +1,6 @@
 // Copyright Vespa.ai. Licensed under the terms of the Apache 2.0 license. See LICENSE in the project root.
 package com.yahoo.text.interpretation;
 
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -28,7 +27,7 @@ public class Annotations {
 
     public Map<String,Object> getMap() {
         if (annotations == null) {
-            return Collections.emptyMap();
+            return Map.of();
         } else {
             return annotations;
         }
diff --git a/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/QueryEncoder.java b/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/QueryEncoder.java
index 112c3669133..c0ded6a4c39 100644
--- a/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/QueryEncoder.java
+++ b/container-search/src/main/java/com/yahoo/vespa/streamingvisitors/QueryEncoder.java
@@ -8,7 +8,6 @@ import com.yahoo.search.Query;
 import com.yahoo.search.dispatch.rpc.ProtobufSerialization;
 
 import java.nio.ByteBuffer;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
 
@@ -68,10 +67,10 @@ class QueryEncoder {
             return cacheSettingMap;
         }
         if (query.getGroupingSessionCache())
-            return Collections.singletonMap("grouping", true);
+            return Map.of("grouping", true);
         if (query.getRanking().getQueryCache())
-            return Collections.singletonMap("query", true);
-        return Collections.emptyMap();
+            return Map.of("query", true);
+        return Map.of();
     }
 
     private static Map<String, String> createModelMap(Query query) {