Use List.of / Map.of / Set.of

Author: gnodet

api/maven-api-core/src/main/java/org/apache/maven/api/services/ArtifactInstaller.java

@@ -19,7 +19,7 @@
 package org.apache.maven.api.services;
 
 import java.util.Collection;
-import java.util.Collections;
+import java.util.List;
 
 import org.apache.maven.api.ProducedArtifact;
 import org.apache.maven.api.Service;
@@ -51,7 +51,7 @@ public interface ArtifactInstaller extends Service {
      *          {@code artifact} is {@code null}
      */
     default void install(Session session, ProducedArtifact artifact) {
-        install(session, Collections.singletonList(artifact));
+        install(session, List.of(artifact));
     }
 
     /**

api/maven-api-core/src/main/java/org/apache/maven/api/services/ArtifactInstallerRequest.java

@@ -19,7 +19,6 @@
 package org.apache.maven.api.services;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 
@@ -62,7 +61,7 @@ static ArtifactInstallerRequest build(Session session, Collection<ProducedArtifa
     class ArtifactInstallerRequestBuilder {
         Session session;
         RequestTrace trace;
-        Collection<ProducedArtifact> artifacts = Collections.emptyList();
+        Collection<ProducedArtifact> artifacts = List.of();
 
         ArtifactInstallerRequestBuilder() {}
 
@@ -80,7 +79,7 @@ public ArtifactInstallerRequestBuilder trace(RequestTrace trace) {
 
         @Nonnull
         public ArtifactInstallerRequestBuilder artifacts(@Nullable Collection<ProducedArtifact> artifacts) {
-            this.artifacts = artifacts != null ? artifacts : Collections.emptyList();
+            this.artifacts = artifacts != null ? artifacts : List.of();
             return this;
         }
 

api/maven-api-core/src/main/java/org/apache/maven/api/services/DependencyCoordinatesFactoryRequest.java

@@ -20,7 +20,7 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
+import java.util.List;
 import java.util.Objects;
 
 import org.apache.maven.api.ArtifactCoordinates;
@@ -117,7 +117,7 @@ class DependencyCoordinatesFactoryRequestBuilder {
         private String coordinateString;
         private String scope;
         private boolean optional;
-        private Collection<Exclusion> exclusions = Collections.emptyList();
+        private Collection<Exclusion> exclusions = List.of();
 
         DependencyCoordinatesFactoryRequestBuilder() {}
 

api/maven-api-core/src/main/java/org/apache/maven/api/services/DependencyResolverRequest.java

@@ -20,7 +20,6 @@
 
 import java.util.ArrayList;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -176,8 +175,8 @@ class DependencyResolverRequestBuilder {
         Project project;
         Artifact rootArtifact;
         DependencyCoordinates root;
-        List<DependencyCoordinates> dependencies = Collections.emptyList();
-        List<DependencyCoordinates> managedDependencies = Collections.emptyList();
+        List<DependencyCoordinates> dependencies = List.of();
+        List<DependencyCoordinates> managedDependencies = List.of();
         boolean verbose;
         PathScope pathScope;
         Predicate<PathType> pathTypeFilter;
@@ -246,7 +245,7 @@ public DependencyResolverRequestBuilder root(@Nonnull DependencyCoordinates root
          */
         @Nonnull
         public DependencyResolverRequestBuilder dependencies(@Nullable List<DependencyCoordinates> dependencies) {
-            this.dependencies = (dependencies != null) ? dependencies : Collections.emptyList();
+            this.dependencies = (dependencies != null) ? dependencies : List.of();
             return this;
         }
 
@@ -278,7 +277,7 @@ public DependencyResolverRequestBuilder dependency(@Nullable DependencyCoordinat
         @Nonnull
         public DependencyResolverRequestBuilder managedDependencies(
                 @Nullable List<DependencyCoordinates> managedDependencies) {
-            this.managedDependencies = (managedDependencies != null) ? managedDependencies : Collections.emptyList();
+            this.managedDependencies = (managedDependencies != null) ? managedDependencies : List.of();
             return this;
         }
 

api/maven-api-model/src/main/java/org/apache/maven/api/model/InputLocation.java

@@ -20,7 +20,6 @@
 
 import java.io.Serializable;
 import java.util.Collection;
-import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.Map;
 
@@ -44,7 +43,7 @@ public InputLocation(InputSource source) {
         this.lineNumber = -1;
         this.columnNumber = -1;
         this.source = source;
-        this.locations = Collections.singletonMap(0, this);
+        this.locations = Map.of(0, this);
         this.importedFrom = null;
     }
 
@@ -60,8 +59,7 @@ public InputLocation(int lineNumber, int columnNumber, InputSource source, Objec
         this.lineNumber = lineNumber;
         this.columnNumber = columnNumber;
         this.source = source;
-        this.locations =
-                selfLocationKey != null ? Collections.singletonMap(selfLocationKey, this) : Collections.emptyMap();
+        this.locations = selfLocationKey != null ? Map.of(selfLocationKey, this) : Map.of();
         this.importedFrom = null;
     }
 

api/maven-api-spi/src/main/java/org/apache/maven/api/spi/LanguageProvider.java

@@ -35,7 +35,7 @@
  * <pre>
  * public class CustomLanguageProvider implements LanguageProvider {
  *     public Collection&lt;Language&gt; provides() {
- *         return Collections.singleton(language("kotlin"));
+ *         return Set.of(language("kotlin"));
  *     }
  * }
  * </pre>

api/maven-api-spi/src/main/java/org/apache/maven/api/spi/LifecycleProvider.java

@@ -37,7 +37,7 @@
  * <pre>
  * public class CustomLifecycleProvider implements LifecycleProvider {
  *     public Collection&lt;Lifecycle&gt; provides() {
- *         return Collections.singleton(
+ *         return Set.of(
  *             lifecycle("deploy-docker", Arrays.asList(
  *                 "build-image",
  *                 "tag-image",

api/maven-api-spi/src/main/java/org/apache/maven/api/spi/PathScopeProvider.java

@@ -37,7 +37,7 @@
  * <pre>
  * public class CustomPathScopeProvider implements PathScopeProvider {
  *     public Collection&lt;PathScope&gt; provides() {
- *         return Collections.singleton(pathScope("integration-test",
+ *         return Set.of(pathScope("integration-test",
  *                 ProjectScope.TEST, DependencyScope.TEST));
  *     }
  * }

api/maven-api-spi/src/main/java/org/apache/maven/api/spi/ProjectScopeProvider.java

@@ -35,7 +35,7 @@
  * <pre>
  * public class CustomProjectScopeProvider implements ProjectScopeProvider {
  *     public Collection&lt;ProjectScope&gt; provides() {
- *         return Collections.singleton(projectScope("integration-test"));
+ *         return Set.of(projectScope("integration-test"));
  *     }
  * }
  * </pre>

compat/maven-resolver-provider/src/main/java/org/apache/maven/repository/internal/ArtifactDescriptorReaderDelegate.java

@@ -19,7 +19,6 @@
 package org.apache.maven.repository.internal;
 
 import java.util.ArrayList;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.List;
@@ -104,7 +103,7 @@ private Dependency convert(org.apache.maven.model.Dependency dependency, Artifac
 
         Map<String, String> props = null;
         if (system) {
-            props = Collections.singletonMap(MavenArtifactProperties.LOCAL_PATH, dependency.getSystemPath());
+            props = Map.of(MavenArtifactProperties.LOCAL_PATH, dependency.getSystemPath());
         }
 
         Artifact artifact = new DefaultArtifact(