NO-JIRA replace guava copy uniqueIndex to Collectors.toMap and simplify lambdas

server/sonar-ce-common/src/main/java/org/sonar/ce/queue/CeQueueImpl.java

@@ -30,6 +30,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
@@ -57,7 +58,6 @@ import static com.google.common.base.Preconditions.checkState;
 import static java.util.Collections.singleton;
 import static java.util.Optional.ofNullable;
 import static org.sonar.ce.queue.CeQueue.SubmitOption.UNIQUE_QUEUE_PER_ENTITY;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.ce.CeQueueDto.Status.IN_PROGRESS;
 import static org.sonar.db.ce.CeQueueDto.Status.PENDING;
 
@@ -228,7 +228,7 @@ public class CeQueueImpl implements CeQueue {
     // these components correspond to a branch or a portfolio (analysis target)
     Map<String, ComponentDto> componentsByUuid = dbClient.componentDao()
       .selectByUuids(dbSession, componentUuids).stream()
-      .collect(uniqueIndex(ComponentDto::uuid));
+      .collect(Collectors.toMap(ComponentDto::uuid, Function.identity()));
     Set<String> entityUuids = dtos.stream().map(CeQueueDto::getEntityUuid).filter(Objects::nonNull).collect(Collectors.toSet());
     Map<String, EntityDto> entitiesByUuid = dbClient.entityDao().selectByUuids(dbSession, entityUuids).stream()
       .collect(Collectors.toMap(EntityDto::getUuid, e -> e));
@@ -249,7 +249,7 @@ public class CeQueueImpl implements CeQueue {
         .map(entitiesByUuid::get)
         .orElse(null);
       Map<String, String> characteristics = characteristicsByTaskUuid.get(dto.getUuid()).stream()
-        .collect(uniqueIndex(CeTaskCharacteristicDto::getKey, CeTaskCharacteristicDto::getValue));
+        .collect(Collectors.toMap(CeTaskCharacteristicDto::getKey, CeTaskCharacteristicDto::getValue));
       result.add(convertToTask(dbSession, dto, characteristics, component, entity));
     }
     return result;

server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/filemove/FileMoveDetectionStep.java

@@ -34,6 +34,7 @@ import java.util.Iterator;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.apache.ibatis.session.ResultContext;
@@ -52,7 +53,6 @@ import org.sonar.ce.task.projectanalysis.filemove.FileSimilarity.LazyFileImpl;
 import org.sonar.ce.task.projectanalysis.source.SourceLinesHashRepository;
 import org.sonar.ce.task.step.ComputationStep;
 import org.sonar.core.util.logs.Profiler;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.component.FileMoveRowDto;
@@ -208,7 +208,7 @@ public class FileMoveDetectionStep implements ComputationStep {
           builder.add(new DbComponent(row.getKey(), row.getUuid(), row.getPath(), row.getLineCount()));
         });
       return builder.build().stream()
-        .collect(MoreCollectors.uniqueIndex(DbComponent::uuid));
+        .collect(Collectors.toMap(DbComponent::uuid, Function.identity()));
     }
   }
 

server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/issue/ComponentIssuesLoader.java

@@ -27,13 +27,15 @@ import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.apache.ibatis.session.ResultContext;
 import org.apache.ibatis.session.ResultHandler;
+import org.slf4j.LoggerFactory;
 import org.sonar.api.config.Configuration;
 import org.sonar.api.rule.RuleKey;
 import org.sonar.api.rule.RuleStatus;
 import org.sonar.api.utils.System2;
-import org.slf4j.LoggerFactory;
 import org.sonar.ce.task.projectanalysis.qualityprofile.ActiveRulesHolder;
 import org.sonar.core.issue.DefaultIssue;
 import org.sonar.core.issue.FieldDiffs;
@@ -48,7 +50,6 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.unmodifiableList;
 import static java.util.stream.Collectors.groupingBy;
 import static org.sonar.api.issue.Issue.STATUS_CLOSED;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.issue.IssueFieldsSetter.FROM_BRANCH;
 import static org.sonar.server.issue.IssueFieldsSetter.STATUS;
 
@@ -163,7 +164,7 @@ public class ComponentIssuesLoader {
    * While loading the changes for the issues, this class will also collect old status changes that should be deleted.
    */
   private void loadLatestDiffChangesForReopeningOfClosedIssues(DbSession dbSession, Collection<DefaultIssue> issues) {
-    Map<String, DefaultIssue> issuesByKey = issues.stream().collect(uniqueIndex(DefaultIssue::key));
+    Map<String, DefaultIssue> issuesByKey = issues.stream().collect(Collectors.toMap(DefaultIssue::key, Function.identity()));
     CollectIssueChangesToDeleteResultHandler collectChangesToDelete = new CollectIssueChangesToDeleteResultHandler(issueChangesToDeleteRepository);
     CollectLastStatusAndResolution collectLastStatusAndResolution = new CollectLastStatusAndResolution(issuesByKey);
 

server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/issue/SiblingsIssuesLoader.java

@@ -24,6 +24,7 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.ce.task.projectanalysis.component.Component;
 import org.sonar.ce.task.projectanalysis.component.SiblingComponentsWithOpenIssues;
@@ -34,7 +35,6 @@ import org.sonar.db.issue.IssueDto;
 import org.sonar.db.issue.PrIssueDto;
 
 import static org.sonar.api.utils.DateUtils.longToDate;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class SiblingsIssuesLoader {
 
@@ -81,7 +81,7 @@ public class SiblingsIssuesLoader {
         .toList();
       componentIssuesLoader.loadChanges(session, issues);
       return issues.stream()
-        .collect(uniqueIndex(i -> issuesByKey.get(i.key()), i -> i, issues.size()));
+        .collect(Collectors.toMap(i -> issuesByKey.get(i.key()), Function.identity()));
     }
   }
 

server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/metric/ReportMetricValidatorImpl.java

@@ -22,11 +22,12 @@ package org.sonar.ce.task.projectanalysis.metric;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;
-import org.sonar.api.measures.Metric;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.sonar.api.measures.Metric;
 import org.sonar.core.metric.ScannerMetrics;
-import org.sonar.core.util.stream.MoreCollectors;
 
 public class ReportMetricValidatorImpl implements ReportMetricValidator {
   private static final Logger LOG = LoggerFactory.getLogger(ReportMetricValidatorImpl.class);
@@ -35,7 +36,7 @@ public class ReportMetricValidatorImpl implements ReportMetricValidator {
   private final Set<String> alreadyLoggedMetricKeys = new HashSet<>();
 
   public ReportMetricValidatorImpl(ScannerMetrics scannerMetrics) {
-    this.metricByKey = scannerMetrics.getMetrics().stream().collect(MoreCollectors.uniqueIndex(Metric::getKey));
+    this.metricByKey = scannerMetrics.getMetrics().stream().collect(Collectors.toMap(Metric::getKey, Function.identity()));
   }
 
   @Override

server/sonar-ce-task-projectanalysis/src/main/java/org/sonar/ce/task/projectanalysis/step/PersistIssuesStep.java

@@ -22,6 +22,7 @@ package org.sonar.ce.task.projectanalysis.step;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.utils.System2;
 import org.sonar.ce.task.projectanalysis.issue.ProtoIssueCache;
@@ -43,7 +44,6 @@ import org.sonar.db.newcodeperiod.NewCodePeriodType;
 import org.sonar.server.issue.IssueStorage;
 
 import static org.sonar.core.util.FileUtils.humanReadableByteCountSI;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class PersistIssuesStep implements ComputationStep {
   // holding up to 1000 DefaultIssue (max size of addedIssues and updatedIssues at any given time) in memory should not
@@ -158,7 +158,7 @@ public class PersistIssuesStep implements ComputationStep {
     List<String> updatedIssueKeys = updatedIssues.stream().map(DefaultIssue::key).toList();
     List<IssueDto> conflictIssueKeys = mapper.selectByKeysIfNotUpdatedAt(updatedIssueKeys, now);
     if (!conflictIssueKeys.isEmpty()) {
-      Map<String, DefaultIssue> issuesByKeys = updatedIssues.stream().collect(uniqueIndex(DefaultIssue::key, updatedIssues.size()));
+      Map<String, DefaultIssue> issuesByKeys = updatedIssues.stream().collect(Collectors.toMap(DefaultIssue::key, Function.identity()));
       conflictIssueKeys
         .forEach(dbIssue -> {
           DefaultIssue updatedIssue = issuesByKeys.get(dbIssue.getKey());

server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/issue/TrackerExecutionTest.java

@@ -23,6 +23,8 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.Random;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.junit.Test;
 import org.sonar.api.issue.Issue;
@@ -42,7 +44,6 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class TrackerExecutionTest {
   private final TrackerBaseInputFactory baseInputFactory = mock(TrackerBaseInputFactory.class);
@@ -128,7 +129,7 @@ public class TrackerExecutionTest {
     ArrayList<DefaultIssue> mappedBaseIssues = new ArrayList<>(mappedClosedIssues);
     Issue.STATUSES.stream().filter(t -> !Issue.STATUS_CLOSED.equals(t)).forEach(s -> mappedBaseIssues.add(new DefaultIssue().setKey(s).setStatus(s)));
     Collections.shuffle(mappedBaseIssues);
-    when(closedTracking.getMatchedRaws()).thenReturn(mappedBaseIssues.stream().collect(uniqueIndex(i -> new DefaultIssue().setKey("raw_for_" + i.key()), i -> i)));
+    when(closedTracking.getMatchedRaws()).thenReturn(mappedBaseIssues.stream().collect(Collectors.toMap(i -> new DefaultIssue().setKey("raw_for_" + i.key()), Function.identity())));
 
     Tracking<DefaultIssue, DefaultIssue> tracking = underTest.track(component, rawInput);
 

server/sonar-ce-task-projectanalysis/src/test/java/org/sonar/ce/task/projectanalysis/notification/NotificationFactoryTest.java

@@ -29,6 +29,7 @@ import java.util.Collections;
 import java.util.Map;
 import java.util.Random;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -71,7 +72,6 @@ import static org.sonar.api.issue.Issue.STATUS_OPEN;
 import static org.sonar.ce.task.projectanalysis.component.Component.Type.DIRECTORY;
 import static org.sonar.ce.task.projectanalysis.component.Component.Type.FILE;
 import static org.sonar.ce.task.projectanalysis.component.Component.Type.PROJECT;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 @RunWith(DataProviderRunner.class)
 public class NotificationFactoryTest {
@@ -140,7 +140,7 @@ public class NotificationFactoryTest {
       .collect(Collectors.toSet());
 
     MyNewIssuesNotification underTest = this.underTest.newMyNewIssuesNotification(
-      users.stream().collect(uniqueIndex(UserDto::getUuid)));
+      users.stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity())));
 
     DetailsSupplier detailsSupplier = readDetailsSupplier(underTest);
     assertThat(detailsSupplier.getUserNameByUuid("foo")).isEmpty();
@@ -184,7 +184,7 @@ public class NotificationFactoryTest {
       .collect(Collectors.toSet());
 
     NewIssuesNotification underTest = this.underTest.newNewIssuesNotification(
-      users.stream().collect(uniqueIndex(UserDto::getUuid)));
+      users.stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity())));
 
     DetailsSupplier detailsSupplier = readDetailsSupplier(underTest);
     assertThat(detailsSupplier.getUserNameByUuid("foo")).isEmpty();
@@ -722,7 +722,7 @@ public class NotificationFactoryTest {
     IssuesChangesNotificationBuilder builder = verifyAndCaptureIssueChangeNotificationBuilder();
     assertThat(builder.getIssues()).hasSize(issues.size());
     Map<String, ChangedIssue> changedIssuesByKey = builder.getIssues().stream()
-      .collect(uniqueIndex(ChangedIssue::getKey));
+      .collect(Collectors.toMap(ChangedIssue::getKey, Function.identity()));
     issues.forEach(
       issue -> {
         ChangedIssue changedIssue = changedIssuesByKey.get(issue.key());
@@ -737,7 +737,7 @@ public class NotificationFactoryTest {
   private static Map<String, UserDto> nonEmptyAssigneesByUuid() {
     return IntStream.range(0, 1 + new Random().nextInt(3))
       .boxed()
-      .collect(uniqueIndex(i -> "uuid_" + i, i -> new UserDto()));
+      .collect(Collectors.toMap(i -> "uuid_" + i, i1 -> new UserDto()));
   }
 
   private IssuesChangesNotificationBuilder verifyAndCaptureIssueChangeNotificationBuilder() {

server/sonar-ce/src/main/java/org/sonar/ce/queue/InternalCeQueueImpl.java

@@ -27,12 +27,13 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
-import org.sonar.api.ce.ComputeEngineSide;
-import org.sonar.api.utils.System2;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.sonar.api.ce.ComputeEngineSide;
+import org.sonar.api.utils.System2;
 import org.sonar.ce.container.ComputeEngineStatus;
 import org.sonar.ce.monitoring.CEQueueStatus;
 import org.sonar.ce.task.CeTask;
@@ -51,7 +52,6 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static java.lang.String.format;
 import static java.util.Collections.singletonList;
 import static java.util.Objects.requireNonNull;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 @ComputeEngineSide
 public class InternalCeQueueImpl extends CeQueueImpl implements InternalCeQueue {
@@ -86,7 +86,7 @@ public class InternalCeQueueImpl extends CeQueueImpl implements InternalCeQueue
       }
       CeQueueDto taskDto = opt.get();
       Map<String, String> characteristics = dbClient.ceTaskCharacteristicsDao().selectByTaskUuids(dbSession, singletonList(taskDto.getUuid())).stream()
-        .collect(uniqueIndex(CeTaskCharacteristicDto::getKey, CeTaskCharacteristicDto::getValue));
+        .collect(Collectors.toMap(CeTaskCharacteristicDto::getKey, CeTaskCharacteristicDto::getValue));
 
       CeTask task = convertToTask(dbSession, taskDto, characteristics);
       queueStatus.addInProgress();

server/sonar-db-dao/src/main/java/org/sonar/db/KeyLongValue.java

@@ -21,8 +21,7 @@ package org.sonar.db;
 
 import java.util.List;
 import java.util.Map;
-
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
+import java.util.stream.Collectors;
 
 public class KeyLongValue {
 
@@ -52,6 +51,6 @@ public class KeyLongValue {
   public static Map<String, Long> toMap(List<KeyLongValue> values) {
     return values
       .stream()
-      .collect(uniqueIndex(KeyLongValue::getKey, KeyLongValue::getValue, values.size()));
+      .collect(Collectors.toMap(KeyLongValue::getKey, KeyLongValue::getValue));
   }
 }

server/sonar-db-migration/src/test/java/org/sonar/server/platform/db/migration/version/v00/PopulateInitialSchemaTest.java

@@ -24,6 +24,7 @@ import java.util.Date;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.junit.Before;
@@ -34,7 +35,6 @@ import org.sonar.api.utils.Version;
 import org.sonar.core.platform.SonarQubeVersion;
 import org.sonar.core.util.UuidFactory;
 import org.sonar.core.util.UuidFactoryFast;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.CoreDbTester;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -158,7 +158,7 @@ public class PopulateInitialSchemaTest {
       " from internal_properties");
     assertThat(rows).hasSize(2);
 
-    Map<String, Map<String, Object>> rowsByKey = rows.stream().collect(MoreCollectors.uniqueIndex(t -> (String) t.get("KEE")));
+    Map<String, Map<String, Object>> rowsByKey = rows.stream().collect(Collectors.toMap(t -> (String) t.get("KEE"), Function.identity()));
     verifyInternalProperty(rowsByKey, "installation.date", String.valueOf(system2.now()));
     verifyInternalProperty(rowsByKey, "installation.version", version.toString());
   }
@@ -181,7 +181,7 @@ public class PopulateInitialSchemaTest {
       " from properties");
     assertThat(rows).hasSize(3);
 
-    Map<String, Map<String, Object>> rowsByKey = rows.stream().collect(MoreCollectors.uniqueIndex(t -> (String) t.get("PROP_KEY")));
+    Map<String, Map<String, Object>> rowsByKey = rows.stream().collect(Collectors.toMap(t -> (String) t.get("PROP_KEY"), Function.identity()));
     verifyProperty(rowsByKey, "sonar.forceAuthentication", "true");
     verifyProperty(rowsByKey, "projects.default.visibility", "public");
     verifyProperty(rowsByKey, "qualitygate.default", qualityGateUuid);

server/sonar-server-common/src/main/java/org/sonar/server/es/IndexDefinitionHash.java

@@ -23,11 +23,11 @@ import com.google.common.collect.ImmutableSortedMap;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.SortedMap;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.apache.commons.codec.digest.DigestUtils;
 import org.sonar.server.es.newindex.BuiltIndex;
 
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
-
 /**
  * Hash of index definition is stored in the index itself in order to detect changes of mappings
  * between SonarQube versions. In this case, contrary to database tables, indices are dropped
@@ -44,7 +44,7 @@ class IndexDefinitionHash {
     return of(
       index.getSettings().toString(),
       Map.of(mainType.getIndex(), mainType),
-      index.getRelationTypes().stream().collect(uniqueIndex(IndexType.IndexRelationType::getName, t -> t)),
+      index.getRelationTypes().stream().collect(Collectors.toMap(IndexType.IndexRelationType::getName, Function.identity())),
       index.getAttributes());
   }
 

server/sonar-server-common/src/main/java/org/sonar/server/issue/notification/IssuesChangesNotificationSerializer.java

@@ -23,6 +23,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
@@ -36,7 +37,6 @@ import org.sonar.server.issue.notification.IssuesChangesNotificationBuilder.User
 import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 import static java.util.Optional.ofNullable;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class IssuesChangesNotificationSerializer {
   private static final String FIELD_ISSUES_COUNT = "issues.count";
@@ -173,7 +173,7 @@ public class IssuesChangesNotificationSerializer {
       .collect(Collectors.toSet())
       .stream()
       .map(ruleKey -> readRule(notification, ruleKey))
-      .collect(uniqueIndex(Rule::getKey, t -> t));
+      .collect(Collectors.toMap(Rule::getKey, Function.identity()));
   }
 
   private static Rule readRule(IssuesChangesNotification notification, RuleKey ruleKey) {
@@ -210,7 +210,7 @@ public class IssuesChangesNotificationSerializer {
           .setBranchName(notification.getFieldValue(projectPropertyPrefix + ".branchName"))
           .build();
       })
-      .collect(uniqueIndex(Project::getUuid, t -> t));
+      .collect(Collectors.toMap(Project::getUuid, Function.identity()));
   }
 
   private static String getProjectFieldValue(IssuesChangesNotification notification, String fieldName, String uuid) {

server/sonar-server-common/src/main/java/org/sonar/server/issue/notification/MyNewIssuesNotificationHandler.java

@@ -25,10 +25,10 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import javax.annotation.CheckForNull;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.server.notification.EmailNotificationHandler;
 import org.sonar.server.notification.NotificationDispatcherMetadata;
 import org.sonar.server.notification.NotificationManager;
@@ -91,7 +91,7 @@ public class MyNewIssuesNotificationHandler extends EmailNotificationHandler<MyN
     Map<String, NotificationManager.EmailRecipient> recipientsByLogin = notificationManager
       .findSubscribedEmailRecipients(KEY, projectKey, assignees, ALL_MUST_HAVE_ROLE_USER)
       .stream()
-      .collect(MoreCollectors.uniqueIndex(NotificationManager.EmailRecipient::login));
+      .collect(Collectors.toMap(NotificationManager.EmailRecipient::login, Function.identity()));
     return notifications.stream()
       .map(notification -> toEmailDeliveryRequest(recipientsByLogin, notification))
       .filter(Objects::nonNull);

server/sonar-server-common/src/main/java/org/sonar/server/qualityprofile/QPMeasureData.java

@@ -26,13 +26,13 @@ import java.io.StringWriter;
 import java.util.Comparator;
 import java.util.Map;
 import java.util.SortedSet;
+import java.util.stream.Collectors;
 import java.util.stream.StreamSupport;
 import javax.annotation.concurrent.Immutable;
 import org.sonar.api.utils.text.JsonWriter;
 import org.sonar.core.util.UtcDateUtils;
 
 import static java.util.function.Function.identity;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 /**
  * Represents the array of JSON objects stored in the value of the
@@ -82,7 +82,7 @@ public class QPMeasureData {
   }
 
   public Map<String, QualityProfile> getProfilesByKey() {
-    return profiles.stream().collect(uniqueIndex(QualityProfile::getQpKey, identity()));
+    return profiles.stream().collect(Collectors.toMap(QualityProfile::getQpKey, identity()));
   }
 
   private enum QualityProfileComparator implements Comparator<QualityProfile> {

server/sonar-server-common/src/main/java/org/sonar/server/security/SecurityStandards.java

@@ -29,6 +29,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
@@ -41,7 +42,6 @@ import static java.util.Arrays.stream;
 import static java.util.Collections.singleton;
 import static java.util.Collections.singletonList;
 import static org.sonar.api.server.rule.RulesDefinition.PciDssVersion.V3_2;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.security.SecurityStandards.VulnerabilityProbability.HIGH;
 import static org.sonar.server.security.SecurityStandards.VulnerabilityProbability.LOW;
 import static org.sonar.server.security.SecurityStandards.VulnerabilityProbability.MEDIUM;
@@ -192,7 +192,7 @@ public final class SecurityStandards {
     PERMISSION("permission", MEDIUM),
     OTHERS("others", LOW);
 
-    private static final Map<String, SQCategory> SQ_CATEGORY_BY_KEY = stream(values()).collect(uniqueIndex(SQCategory::getKey));
+    private static final Map<String, SQCategory> SQ_CATEGORY_BY_KEY = stream(values()).collect(Collectors.toMap(SQCategory::getKey, Function.identity()));
     private final String key;
     private final VulnerabilityProbability vulnerability;
 

server/sonar-server-common/src/main/java/org/sonar/server/setting/DatabaseSettingLoader.java

@@ -20,7 +20,7 @@
 package org.sonar.server.setting;
 
 import java.util.Map;
-import org.sonar.core.util.stream.MoreCollectors;
+import java.util.stream.Collectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.property.PropertyDto;
@@ -49,7 +49,7 @@ public class DatabaseSettingLoader implements SettingLoader {
     try (DbSession dbSession = dbClient.openSession(false)) {
       return dbClient.propertiesDao().selectGlobalProperties(dbSession)
         .stream()
-        .collect(MoreCollectors.uniqueIndex(PropertyDto::getKey, p -> defaultString(p.getValue())));
+        .collect(Collectors.toMap(PropertyDto::getKey, p -> defaultString(p.getValue())));
     }
   }
 

server/sonar-server-common/src/test/java/org/sonar/server/telemetry/TelemetryDataJsonWriterTest.java

@@ -40,7 +40,6 @@ import org.sonar.api.utils.System2;
 import org.sonar.api.utils.text.JsonWriter;
 import org.sonar.core.platform.EditionProvider;
 import org.sonar.core.telemetry.TelemetryExtension;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.user.UserTelemetryDto;
 
 import static java.util.stream.Collectors.joining;
@@ -160,7 +159,7 @@ public class TelemetryDataJsonWriterTest {
   public void writes_all_plugins() {
     Map<String, String> plugins = IntStream.range(0, 1 + random.nextInt(10))
       .boxed()
-      .collect(MoreCollectors.uniqueIndex(i -> "P" + i, i -> "V" + i));
+      .collect(Collectors.toMap(i -> "P" + i, i1 -> "V" + i1));
     TelemetryData data = telemetryBuilder()
       .setPlugins(plugins)
       .build();

server/sonar-webserver-api/src/main/java/org/sonar/server/rule/CachingRuleFinder.java

@@ -44,7 +44,6 @@ import org.sonar.db.rule.RuleParamDto;
 
 import static java.util.Collections.emptyList;
 import static java.util.Collections.unmodifiableMap;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 /**
  * A {@link RuleFinder} implementation that retrieves all rule definitions and their parameter when instantiated, cache
@@ -68,7 +67,7 @@ public class CachingRuleFinder implements ServerRuleFinder {
       this.ruleDtosByUuid = dtos.stream().collect(Collectors.toMap(RuleDto::getUuid, d -> d));
       this.ruleByRuleDto = buildRulesByRuleDefinitionDto(dbClient, dbSession, dtos);
       this.rulesByKey = this.ruleByRuleDto.entrySet().stream()
-        .collect(uniqueIndex(entry -> entry.getKey().getKey(), Map.Entry::getValue));
+        .collect(Collectors.toMap(entry -> entry.getKey().getKey(), Map.Entry::getValue));
     }
   }
 

server/sonar-webserver-auth/src/main/java/org/sonar/server/authentication/UserRegistrarImpl.java

@@ -29,12 +29,14 @@ import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
-import org.sonar.api.server.authentication.IdentityProvider;
-import org.sonar.api.server.authentication.UserIdentity;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.sonar.api.server.authentication.IdentityProvider;
+import org.sonar.api.server.authentication.UserIdentity;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.user.GroupDto;
@@ -51,7 +53,6 @@ import org.sonar.server.usergroups.DefaultGroupFinder;
 
 import static java.lang.String.format;
 import static java.util.Collections.singletonList;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.user.UserSession.IdentityProvider.SONARQUBE;
 
 public class UserRegistrarImpl implements UserRegistrar {
@@ -235,7 +236,7 @@ public class UserRegistrarImpl implements UserRegistrar {
     allGroups.addAll(groupsToRemove);
     Map<String, GroupDto> groupsByName = dbClient.groupDao().selectByNames(dbSession, allGroups)
       .stream()
-      .collect(uniqueIndex(GroupDto::getName));
+      .collect(Collectors.toMap(GroupDto::getName, Function.identity()));
 
     addGroups(dbSession, userDto, groupsToAdd, groupsByName);
     removeGroups(dbSession, userDto, groupsToRemove, groupsByName);

server/sonar-webserver-core/src/it/java/org/sonar/server/startup/RegisterMetricsIT.java

@@ -23,6 +23,8 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 import java.util.Random;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.junit.Rule;
 import org.junit.Test;
@@ -39,7 +41,6 @@ import org.sonar.db.metric.MetricDto;
 import static java.util.Arrays.asList;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class RegisterMetricsIT {
 
@@ -174,7 +175,7 @@ public class RegisterMetricsIT {
   private Map<String, MetricDto> selectAllMetrics() {
     return dbTester.getDbClient().metricDao().selectAll(dbTester.getSession())
       .stream()
-      .collect(uniqueIndex(MetricDto::getKey));
+      .collect(Collectors.toMap(MetricDto::getKey, Function.identity()));
   }
 
   private void assertEquals(Metric expected, MetricDto actual) {

server/sonar-webserver-core/src/it/java/org/sonar/server/startup/RegisterPluginsIT.java

@@ -23,6 +23,8 @@ import java.io.File;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.apache.commons.io.FileUtils;
 import org.junit.Before;
@@ -31,20 +33,19 @@ import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
 import org.sonar.api.utils.System2;
 import org.sonar.core.platform.PluginInfo;
+import org.sonar.core.plugin.PluginType;
 import org.sonar.core.util.UuidFactory;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbTester;
 import org.sonar.db.plugin.PluginDto;
 import org.sonar.db.plugin.PluginDto.Type;
 import org.sonar.server.plugins.PluginFilesAndMd5;
-import org.sonar.core.plugin.PluginType;
 import org.sonar.server.plugins.ServerPlugin;
 import org.sonar.server.plugins.ServerPluginRepository;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class RegisterPluginsIT {
 
@@ -223,7 +224,7 @@ public class RegisterPluginsIT {
 
   private Map<String, PluginDto> selectAllPlugins() {
     return dbTester.getDbClient().pluginDao().selectAll(dbTester.getSession()).stream()
-      .collect(uniqueIndex(PluginDto::getKee));
+      .collect(Collectors.toMap(PluginDto::getKee, Function.identity()));
   }
 
   private void verify(PluginDto pluginDto, Type type, @Nullable String basePluginKey, String fileHash, boolean removed, @Nullable Long createdAt, long updatedAt) {

server/sonar-webserver-core/src/main/java/org/sonar/server/rule/RegisterRules.java

@@ -32,6 +32,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.function.Supplier;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -77,7 +78,6 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.emptySet;
 import static java.util.Collections.unmodifiableMap;
 import static org.apache.commons.lang.StringUtils.isNotEmpty;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 /**
  * Register rules at server startup
@@ -156,7 +156,7 @@ public class RegisterRules implements Startable {
 
   private RegisterRulesContext createRegisterRulesContext(DbSession dbSession) {
     Map<RuleKey, RuleDto> allRules = dbClient.ruleDao().selectAll(dbSession).stream()
-      .collect(uniqueIndex(RuleDto::getKey));
+      .collect(Collectors.toMap(RuleDto::getKey, Function.identity()));
     Map<String, Set<SingleDeprecatedRuleKey>> existingDeprecatedKeysById = loadDeprecatedRuleKeys(dbSession);
     Map<String, List<RuleParamDto>> ruleParamsByRuleUuid = loadAllRuleParameters(dbSession);
     return new RegisterRulesContext(allRules, existingDeprecatedKeysById, ruleParamsByRuleUuid);
@@ -199,7 +199,7 @@ public class RegisterRules implements Startable {
     private static Map<RuleKey, RuleDto> buildDbRulesByDbDeprecatedKey(Map<String, Set<SingleDeprecatedRuleKey>> dbDeprecatedKeysByUuid,
       Map<RuleKey, RuleDto> dbRules) {
       Map<String, RuleDto> dbRulesByRuleUuid = dbRules.values().stream()
-        .collect(uniqueIndex(RuleDto::getUuid));
+        .collect(Collectors.toMap(RuleDto::getUuid, Function.identity()));
 
       Map<RuleKey, RuleDto> rulesByKey = new LinkedHashMap<>();
       for (Map.Entry<String, Set<SingleDeprecatedRuleKey>> entry : dbDeprecatedKeysByUuid.entrySet()) {
@@ -236,7 +236,7 @@ public class RegisterRules implements Startable {
     private Map<RuleKey, SingleDeprecatedRuleKey> getDbDeprecatedKeysByOldRuleKey() {
       return dbDeprecatedKeysByUuid.values().stream()
         .flatMap(Collection::stream)
-        .collect(uniqueIndex(SingleDeprecatedRuleKey::getOldRuleKeyAsRuleKey));
+        .collect(Collectors.toMap(SingleDeprecatedRuleKey::getOldRuleKeyAsRuleKey, Function.identity()));
     }
 
     private Set<SingleDeprecatedRuleKey> getDBDeprecatedKeysFor(RuleDto rule) {

server/sonar-webserver-core/src/main/java/org/sonar/server/telemetry/TelemetryDataLoaderImpl.java

@@ -42,7 +42,6 @@ import org.sonar.api.server.ServerSide;
 import org.sonar.core.platform.PlatformEditionProvider;
 import org.sonar.core.platform.PluginInfo;
 import org.sonar.core.platform.PluginRepository;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.alm.setting.ALM;
@@ -151,8 +150,7 @@ public class TelemetryDataLoaderImpl implements TelemetryDataLoader {
     data.setVersion(server.getVersion());
     data.setEdition(editionProvider.get().orElse(null));
     Function<PluginInfo, String> getVersion = plugin -> plugin.getVersion() == null ? "undefined" : plugin.getVersion().getName();
-    Map<String, String> plugins = pluginRepository.getPluginInfos().stream().collect(MoreCollectors.uniqueIndex(PluginInfo::getKey,
-      getVersion));
+    Map<String, String> plugins = pluginRepository.getPluginInfos().stream().collect(toMap(PluginInfo::getKey, getVersion));
     data.setPlugins(plugins);
     try (DbSession dbSession = dbClient.openSession(false)) {
       var branchMeasuresDtos = dbClient.branchDao().selectBranchMeasuresWithCaycMetric(dbSession);

server/sonar-webserver-es/src/it/java/org/sonar/server/permission/index/PermissionIndexerDaoIT.java

@@ -24,17 +24,16 @@ import java.util.Collection;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.assertj.core.api.Assertions;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
 import org.sonar.api.utils.System2;
 import org.sonar.core.util.Uuids;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.DbTester;
-import org.sonar.db.component.ComponentDbTester;
 import org.sonar.db.component.ProjectData;
 import org.sonar.db.permission.GroupPermissionDto;
 import org.sonar.db.portfolio.PortfolioDto;
@@ -126,7 +125,7 @@ public class PermissionIndexerDaoIT {
       .selectByUuids(dbClient, dbSession,
         asList(publicProject.getUuid(), privateProject1.getUuid(), privateProject2.getUuid(), view1.getUuid(), view2.getUuid(), application.getUuid()))
       .stream()
-      .collect(MoreCollectors.uniqueIndex(IndexPermissions::getEntityUuid, Function.identity()));
+      .collect(Collectors.toMap(IndexPermissions::getEntityUuid, Function.identity()));
     Assertions.assertThat(dtos).hasSize(6);
 
     IndexPermissions publicProjectAuthorization = dtos.get(publicProject.getUuid());

server/sonar-webserver-es/src/main/java/org/sonar/server/issue/index/IssueIndex.java

@@ -33,6 +33,7 @@ import java.util.OptionalInt;
 import java.util.OptionalLong;
 import java.util.Set;
 import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
@@ -106,7 +107,6 @@ import static org.elasticsearch.index.query.QueryBuilders.termQuery;
 import static org.elasticsearch.index.query.QueryBuilders.termsQuery;
 import static org.sonar.api.rules.RuleType.SECURITY_HOTSPOT;
 import static org.sonar.api.rules.RuleType.VULNERABILITY;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.es.EsUtils.escapeSpecialRegexChars;
 import static org.sonar.server.es.IndexType.FIELD_INDEX_TYPE;
 import static org.sonar.server.es.searchrequest.TopAggregationDefinition.NON_STICKY;
@@ -304,7 +304,7 @@ public class IssueIndex {
   }
 
   private static final Map<String, Facet> FACETS_BY_NAME = Arrays.stream(Facet.values())
-    .collect(uniqueIndex(Facet::getName));
+    .collect(Collectors.toMap(Facet::getName, Function.identity()));
 
   private static final String SUBSTRING_MATCH_REGEXP = ".*%s.*";
   // TODO to be documented

server/sonar-webserver-es/src/main/java/org/sonar/server/issue/index/IssueQueryFactory.java

@@ -72,7 +72,6 @@ import static org.sonar.api.utils.DateUtils.longToDate;
 import static org.sonar.api.utils.DateUtils.parseEndingDateOrDateTime;
 import static org.sonar.api.utils.DateUtils.parseStartingDateOrDateTime;
 import static org.sonar.api.web.UserRole.USER;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.newcodeperiod.NewCodePeriodType.REFERENCE_BRANCH;
 import static org.sonarqube.ws.client.issue.IssuesWsParameters.PARAM_COMPONENT_KEYS;
 import static org.sonarqube.ws.client.issue.IssuesWsParameters.PARAM_COMPONENT_UUIDS;
@@ -394,7 +393,7 @@ public class IssueQueryFactory {
     Map<String, PeriodStart> leakByProjects = snapshots
       .stream()
       .filter(s -> s.getPeriodDate() != null && !isLastAnalysisFromReAnalyzedReferenceBranch(dbSession, s))
-      .collect(uniqueIndex(SnapshotDto::getRootComponentUuid, s -> new PeriodStart(longToDate(s.getPeriodDate()), false)));
+      .collect(Collectors.toMap(SnapshotDto::getRootComponentUuid, s1 -> new PeriodStart(longToDate(s1.getPeriodDate()), false)));
 
     builder.createdAfterByProjectUuids(leakByProjects);
     builder.newCodeOnReferenceByProjectUuids(newCodeReferenceByProjects);

server/sonar-webserver-es/src/main/java/org/sonar/server/measure/index/ProjectMeasuresIndex.java

@@ -59,7 +59,6 @@ import org.sonar.api.measures.Metric;
 import org.sonar.api.resources.Qualifiers;
 import org.sonar.api.server.ServerSide;
 import org.sonar.api.utils.System2;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.server.es.EsClient;
 import org.sonar.server.es.SearchIdResult;
 import org.sonar.server.es.SearchOptions;
@@ -105,7 +104,6 @@ import static org.sonar.api.measures.CoreMetrics.SECURITY_HOTSPOTS_REVIEWED_KEY;
 import static org.sonar.api.measures.CoreMetrics.SECURITY_RATING_KEY;
 import static org.sonar.api.measures.CoreMetrics.SECURITY_REVIEW_RATING_KEY;
 import static org.sonar.api.measures.CoreMetrics.SQALE_RATING_KEY;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.es.EsUtils.escapeSpecialRegexChars;
 import static org.sonar.server.es.EsUtils.termsToMap;
 import static org.sonar.server.es.IndexType.FIELD_INDEX_TYPE;
@@ -204,7 +202,7 @@ public class ProjectMeasuresIndex {
   }
 
   private static final Map<String, Facet> FACETS_BY_NAME = Arrays.stream(Facet.values())
-    .collect(uniqueIndex(Facet::getName));
+    .collect(Collectors.toMap(Facet::getName, Function.identity()));
 
   private final EsClient client;
   private final WebAuthorizationTypeSupport authorizationTypeSupport;
@@ -289,7 +287,7 @@ public class ProjectMeasuresIndex {
     Map<String, Long> nclocByLanguage = Stream.of((Nested) response.getAggregations().get(FIELD_NCLOC_DISTRIBUTION))
       .map(nested -> (Terms) nested.getAggregations().get(nested.getName() + "_terms"))
       .flatMap(terms -> terms.getBuckets().stream())
-      .collect(MoreCollectors.uniqueIndex(Bucket::getKeyAsString, bucketToNcloc));
+      .collect(Collectors.toMap(Bucket::getKeyAsString, bucketToNcloc));
     statistics.setNclocByLanguage(nclocByLanguage);
 
     return statistics.build();

server/sonar-webserver-es/src/main/java/org/sonar/server/permission/index/PermissionIndexer.java

@@ -27,9 +27,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.es.EsQueueDto;
@@ -70,7 +70,7 @@ public class PermissionIndexer implements EventIndexer {
     this.authorizationScopes = authorizationScopes;
     this.indexTypeByFormat = authorizationScopes.stream()
       .map(AuthorizationScope::getIndexType)
-      .collect(MoreCollectors.uniqueIndex(IndexType.IndexMainType::format, t -> t, authorizationScopes.size()));
+      .collect(Collectors.toMap(IndexType.IndexMainType::format, Function.identity()));
   }
 
   @Override

server/sonar-webserver-webapi/src/it/java/org/sonar/server/ce/queue/BranchReportSubmitterIT.java

@@ -19,7 +19,6 @@
  */
 package org.sonar.server.ce.queue;
 
-import com.google.common.collect.ImmutableMap;
 import com.tngtech.java.junit.dataprovider.DataProviderRunner;
 import java.awt.event.ComponentEvent;
 import java.io.InputStream;
@@ -27,6 +26,7 @@ import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Random;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.apache.commons.io.IOUtils;
 import org.junit.Before;
@@ -73,7 +73,6 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.verifyNoMoreInteractions;
 import static org.mockito.Mockito.when;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.component.ComponentTesting.newBranchDto;
 import static org.sonar.db.component.ComponentTesting.newPrivateProjectDto;
 import static org.sonar.db.permission.GlobalPermission.PROVISION_PROJECTS;
@@ -291,10 +290,10 @@ public class BranchReportSubmitterIT {
     return componentKey;
   }
 
-  private static ImmutableMap<String, String> randomNonEmptyMap() {
+  private static Map<String, String> randomNonEmptyMap() {
     return IntStream.range(0, 1 + new Random().nextInt(5))
       .boxed()
-      .collect(uniqueIndex(i -> "key_" + i, i -> "val_" + i));
+      .collect(Collectors.toMap(i -> "key_" + i, i1 -> "val_" + i1));
   }
 
 }

server/sonar-webserver-webapi/src/it/java/org/sonar/server/ce/queue/ReportSubmitterIT.java

@@ -22,6 +22,7 @@ package org.sonar.server.ce.queue;
 import java.io.InputStream;
 import java.util.Map;
 import java.util.Random;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.apache.commons.io.IOUtils;
 import org.junit.Before;
@@ -66,7 +67,6 @@ import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.verifyNoInteractions;
 import static org.mockito.Mockito.when;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.component.BranchDto.DEFAULT_MAIN_BRANCH_NAME;
 import static org.sonar.db.component.ComponentTesting.newDirectory;
 import static org.sonar.db.permission.GlobalPermission.PROVISION_PROJECTS;
@@ -114,7 +114,7 @@ public class ReportSubmitterIT {
       .thenReturn(true);
     Map<String, String> nonEmptyCharacteristics = IntStream.range(0, 1 + new Random().nextInt(5))
       .boxed()
-      .collect(uniqueIndex(i -> randomAlphabetic(i + 10), i -> randomAlphabetic(i + 20)));
+      .collect(Collectors.toMap(i -> randomAlphabetic(i + 10), i1 -> randomAlphabetic(i1 + 20)));
     InputStream reportInput = IOUtils.toInputStream("{binary}", UTF_8);
 
     assertThatThrownBy(() -> underTest.submit(PROJECT_KEY, PROJECT_NAME, nonEmptyCharacteristics, reportInput))

server/sonar-webserver-webapi/src/it/java/org/sonar/server/hotspot/ws/SearchActionIT.java

@@ -33,6 +33,8 @@ import java.util.Map;
 import java.util.Random;
 import java.util.Set;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
@@ -106,7 +108,6 @@ import static org.sonar.api.issue.Issue.STATUS_TO_REVIEW;
 import static org.sonar.api.rules.RuleType.SECURITY_HOTSPOT;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
 import static org.sonar.api.web.UserRole.USER;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.component.ComponentTesting.newDirectory;
 import static org.sonar.db.component.ComponentTesting.newDirectoryOnBranch;
 import static org.sonar.db.component.ComponentTesting.newFileDto;
@@ -1109,7 +1110,7 @@ public class SearchActionIT {
     assertThat(response.getComponentsList())
       .extracting(Component::getKey)
       .containsOnly(project.getKey(), directory.getKey(), file.getKey());
-    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(uniqueIndex(Component::getKey));
+    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(Collectors.toMap(Component::getKey, Function.identity()));
     Component actualProject = componentByKey.get(project.getKey());
     assertThat(actualProject.getQualifier()).isEqualTo(project.qualifier());
     assertThat(actualProject.getName()).isEqualTo(project.name());
@@ -1158,7 +1159,7 @@ public class SearchActionIT {
     assertThat(response.getComponentsList())
       .extracting(Component::getKey)
       .containsOnly(project.getKey(), directory.getKey(), file.getKey());
-    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(uniqueIndex(Component::getKey));
+    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(Collectors.toMap(Component::getKey, Function.identity()));
     Component actualProject = componentByKey.get(project.getKey());
     assertThat(actualProject.getBranch()).isEqualTo(branchName);
     assertThat(actualProject.hasPullRequest()).isFalse();
@@ -1196,7 +1197,7 @@ public class SearchActionIT {
     assertThat(response.getComponentsList())
       .extracting(Component::getKey)
       .containsOnly(project.getKey(), directory.getKey(), file.getKey());
-    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(uniqueIndex(Component::getKey));
+    Map<String, Component> componentByKey = response.getComponentsList().stream().collect(Collectors.toMap(Component::getKey, Function.identity()));
     Component actualProject = componentByKey.get(project.getKey());
     assertThat(actualProject.hasBranch()).isFalse();
     assertThat(actualProject.getPullRequest()).isEqualTo(pullRequestKey);

server/sonar-webserver-webapi/src/it/java/org/sonar/server/qualityprofile/RegisterQualityProfilesNotificationIT.java

@@ -26,6 +26,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Random;
 import java.util.function.Consumer;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.junit.Rule;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
@@ -35,10 +37,9 @@ import org.sonar.api.rules.RulePriority;
 import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition;
 import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition.BuiltInActiveRule;
 import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition.NewBuiltInQualityProfile;
-import org.sonar.api.utils.System2;
 import org.sonar.api.testfixtures.log.LogTester;
+import org.sonar.api.utils.System2;
 import org.sonar.core.util.UuidFactoryFast;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbTester;
 import org.sonar.db.qualityprofile.ActiveRuleDto;
@@ -322,7 +323,7 @@ public class RegisterQualityProfilesNotificationIT {
 
   private static BuiltInQProfile.ActiveRule[] toActiveRules(List<BuiltInActiveRule> rules, RuleDto[] dbRules) {
     Map<RuleKey, RuleDto> dbRulesByRuleKey = Arrays.stream(dbRules)
-      .collect(MoreCollectors.uniqueIndex(RuleDto::getKey));
+      .collect(Collectors.toMap(RuleDto::getKey, Function.identity()));
     return rules.stream()
       .map(r -> {
         RuleKey ruleKey = RuleKey.of(r.repoKey(), r.ruleKey());

server/sonar-webserver-webapi/src/it/java/org/sonar/server/qualityprofile/builtin/BuiltInQProfileRepositoryRule.java

@@ -25,11 +25,12 @@ import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.junit.rules.ExternalResource;
 import org.sonar.api.resources.Language;
 import org.sonar.api.rule.RuleKey;
 import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.rule.RuleDto;
 
 import static com.google.common.base.Preconditions.checkState;
@@ -90,7 +91,7 @@ public class BuiltInQProfileRepositoryRule extends ExternalResource implements B
       .setName(api.name())
       .setDeclaredDefault(api.isDefault());
     Map<RuleKey, RuleDto> rulesByRuleKey = Arrays.stream(rules)
-      .collect(MoreCollectors.uniqueIndex(RuleDto::getKey));
+      .collect(Collectors.toMap(RuleDto::getKey, Function.identity()));
     api.rules().forEach(rule -> {
       RuleKey ruleKey = RuleKey.of(rule.repoKey(), rule.ruleKey());
       RuleDto ruleDto = rulesByRuleKey.get(ruleKey);

server/sonar-webserver-webapi/src/main/java/org/sonar/server/branch/ws/ListAction.java

@@ -23,6 +23,8 @@ import com.google.common.io.Resources;
 import java.util.Collection;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.sonar.api.server.ws.Change;
 import org.sonar.api.server.ws.Request;
@@ -46,7 +48,6 @@ import static java.util.Optional.ofNullable;
 import static org.sonar.api.measures.CoreMetrics.ALERT_STATUS_KEY;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
 import static org.sonar.api.web.UserRole.USER;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.component.BranchType.BRANCH;
 import static org.sonar.db.permission.GlobalPermission.SCAN;
 import static org.sonar.server.branch.ws.BranchesWs.addProjectParam;
@@ -93,10 +94,10 @@ public class ListAction implements BranchWsAction {
 
       Map<String, LiveMeasureDto> qualityGateMeasuresByComponentUuids = dbClient.liveMeasureDao()
         .selectByComponentUuidsAndMetricKeys(dbSession, branchUuids, singletonList(ALERT_STATUS_KEY)).stream()
-        .collect(uniqueIndex(LiveMeasureDto::getComponentUuid));
+        .collect(Collectors.toMap(LiveMeasureDto::getComponentUuid, Function.identity()));
       Map<String, String> analysisDateByBranchUuid = dbClient.snapshotDao()
         .selectLastAnalysesByRootComponentUuids(dbSession, branchUuids).stream()
-        .collect(uniqueIndex(SnapshotDto::getRootComponentUuid, s -> formatDateTime(s.getCreatedAt())));
+        .collect(Collectors.toMap(SnapshotDto::getRootComponentUuid, s -> formatDateTime(s.getCreatedAt())));
 
       ProjectBranches.ListWsResponse.Builder protobufResponse = ProjectBranches.ListWsResponse.newBuilder();
       branches.forEach(b -> addBranch(protobufResponse, b, qualityGateMeasuresByComponentUuids.get(b.getUuid()),

server/sonar-webserver-webapi/src/main/java/org/sonar/server/ce/ws/TaskFormatter.java

@@ -27,6 +27,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
@@ -48,7 +49,6 @@ import static java.lang.String.format;
 import static java.util.Collections.singletonList;
 import static java.util.Optional.ofNullable;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 /**
  * Converts {@link CeActivityDto} and {@link CeQueueDto} to the protobuf objects
@@ -179,12 +179,12 @@ public class TaskFormatter {
     static DtoCache forQueueDtos(DbClient dbClient, DbSession dbSession, Collection<CeQueueDto> ceQueueDtos) {
       Map<String, ComponentDto> componentsByUuid = dbClient.componentDao().selectByUuids(dbSession, componentUuidsOfCeQueues(ceQueueDtos))
         .stream()
-        .collect(uniqueIndex(ComponentDto::uuid));
+        .collect(Collectors.toMap(ComponentDto::uuid, Function.identity()));
       Multimap<String, CeTaskCharacteristicDto> characteristicsByTaskUuid = dbClient.ceTaskCharacteristicsDao()
         .selectByTaskUuids(dbSession, ceQueueDtos.stream().map(CeQueueDto::getUuid).toList())
         .stream().collect(MoreCollectors.index(CeTaskCharacteristicDto::getTaskUuid));
       Set<String> submitterUuids = ceQueueDtos.stream().map(CeQueueDto::getSubmitterUuid).filter(Objects::nonNull).collect(Collectors.toSet());
-      Map<String, UserDto> usersByUuid = dbClient.userDao().selectByUuids(dbSession, submitterUuids).stream().collect(uniqueIndex(UserDto::getUuid));
+      Map<String, UserDto> usersByUuid = dbClient.userDao().selectByUuids(dbSession, submitterUuids).stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
       return new DtoCache(componentsByUuid, characteristicsByTaskUuid, usersByUuid);
     }
 
@@ -201,12 +201,12 @@ public class TaskFormatter {
           dbSession,
           getComponentUuidsOfCeActivities(ceActivityDtos))
         .stream()
-        .collect(uniqueIndex(ComponentDto::uuid));
+        .collect(Collectors.toMap(ComponentDto::uuid, Function.identity()));
       Multimap<String, CeTaskCharacteristicDto> characteristicsByTaskUuid = dbClient.ceTaskCharacteristicsDao()
         .selectByTaskUuids(dbSession, ceActivityDtos.stream().map(CeActivityDto::getUuid).toList())
         .stream().collect(MoreCollectors.index(CeTaskCharacteristicDto::getTaskUuid));
       Set<String> submitterUuids = ceActivityDtos.stream().map(CeActivityDto::getSubmitterUuid).filter(Objects::nonNull).collect(Collectors.toSet());
-      Map<String, UserDto> usersByUuid = dbClient.userDao().selectByUuids(dbSession, submitterUuids).stream().collect(uniqueIndex(UserDto::getUuid));
+      Map<String, UserDto> usersByUuid = dbClient.userDao().selectByUuids(dbSession, submitterUuids).stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
       return new DtoCache(componentsByUuid, characteristicsByTaskUuid, usersByUuid);
     }
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/component/ws/SuggestionsAction.java

@@ -30,6 +30,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
@@ -262,7 +263,7 @@ public class SuggestionsAction implements ComponentsWsAction {
   private SuggestionsWsResponse.Builder buildResponse(Set<String> recentlyBrowsedKeys, Set<String> favoriteUuids, ComponentIndexResults componentsPerQualifiers,
     List<EntityDto> entities, int coveredItems) {
 
-    Map<String, EntityDto> entitiesByUuids = entities.stream().collect(MoreCollectors.uniqueIndex(EntityDto::getUuid));
+    Map<String, EntityDto> entitiesByUuids = entities.stream().collect(Collectors.toMap(EntityDto::getUuid, Function.identity()));
     return toResponse(componentsPerQualifiers, recentlyBrowsedKeys, favoriteUuids, entitiesByUuids, coveredItems);
   }
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/component/ws/TreeAction.java

@@ -42,7 +42,6 @@ import org.sonar.api.server.ws.WebService.Param;
 import org.sonar.api.utils.Paging;
 import org.sonar.api.web.UserRole;
 import org.sonar.core.i18n.I18n;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.component.BranchDto;
@@ -66,8 +65,8 @@ import static org.sonar.server.component.ws.ComponentDtoToWsComponent.projectOrA
 import static org.sonar.server.ws.KeyExamples.KEY_BRANCH_EXAMPLE_001;
 import static org.sonar.server.ws.KeyExamples.KEY_PROJECT_EXAMPLE_001;
 import static org.sonar.server.ws.KeyExamples.KEY_PULL_REQUEST_EXAMPLE_001;
-import static org.sonar.server.ws.WsParameterBuilder.QualifierParameterContext.newQualifierParameterContext;
 import static org.sonar.server.ws.WsParameterBuilder.createQualifiersParameter;
+import static org.sonar.server.ws.WsParameterBuilder.QualifierParameterContext.newQualifierParameterContext;
 import static org.sonar.server.ws.WsUtils.writeProtobuf;
 import static org.sonarqube.ws.client.component.ComponentsWsParameters.ACTION_TREE;
 import static org.sonarqube.ws.client.component.ComponentsWsParameters.PARAM_BRANCH;
@@ -211,7 +210,7 @@ public class TreeAction implements ComponentsWsAction {
     }
 
     return dbClient.componentDao().selectByUuids(dbSession, referenceComponentIds).stream()
-      .collect(MoreCollectors.uniqueIndex(ComponentDto::uuid));
+      .collect(Collectors.toMap(ComponentDto::uuid, java.util.function.Function.identity()));
   }
 
   private void checkPermissions(ComponentDto baseComponent) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/developers/ws/SearchEventsAction.java

@@ -26,6 +26,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
@@ -58,7 +59,6 @@ import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Comparator.comparing;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
 import static org.sonar.api.utils.DateUtils.parseDateTimeQuietly;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.component.BranchType.BRANCH;
 import static org.sonar.db.component.BranchType.PULL_REQUEST;
 import static org.sonar.server.developers.ws.UuidFromPairs.fromDates;
@@ -132,7 +132,7 @@ public class SearchEventsAction implements DevelopersWsAction {
 
     try (DbSession dbSession = dbClient.openSession(false)) {
       List<ProjectDto> authorizedProjects = searchProjects(dbSession, projectKeys);
-      Map<String, ProjectDto> projectsByUuid = authorizedProjects.stream().collect(uniqueIndex(ProjectDto::getUuid));
+      Map<String, ProjectDto> projectsByUuid = authorizedProjects.stream().collect(Collectors.toMap(ProjectDto::getUuid, Function.identity()));
       List<UuidFromPair> uuidFromPairs = buildUuidFromPairs(fromDates, projectKeys, authorizedProjects);
       List<SnapshotDto> analyses = dbClient.snapshotDao().selectFinishedByProjectUuidsAndFromDates(dbSession, projectUuids(uuidFromPairs), fromDates(uuidFromPairs));
 
@@ -141,7 +141,8 @@ public class SearchEventsAction implements DevelopersWsAction {
       }
 
       List<String> branchUuids = analyses.stream().map(SnapshotDto::getRootComponentUuid).toList();
-      Map<String, BranchDto> branchesByUuids = dbClient.branchDao().selectByUuids(dbSession, branchUuids).stream().collect(uniqueIndex(BranchDto::getUuid));
+      Map<String, BranchDto> branchesByUuids = dbClient.branchDao().selectByUuids(dbSession, branchUuids)
+        .stream().collect(Collectors.toMap(BranchDto::getUuid, Function.identity()));
 
       return Stream.concat(
         computeQualityGateChangeEvents(dbSession, projectsByUuid, branchesByUuids, analyses),
@@ -226,7 +227,7 @@ public class SearchEventsAction implements DevelopersWsAction {
   private static List<UuidFromPair> buildUuidFromPairs(List<Long> fromDates, List<String> projectKeys, List<ProjectDto> authorizedProjects) {
     checkRequest(projectKeys.size() == fromDates.size(), "The number of components (%s) and from dates (%s) must be the same.", projectKeys.size(), fromDates.size());
     Map<String, Long> fromDatesByProjectKey = IntStream.range(0, projectKeys.size()).boxed()
-      .collect(uniqueIndex(projectKeys::get, fromDates::get));
+      .collect(Collectors.toMap(projectKeys::get, fromDates::get));
     return authorizedProjects.stream()
       .map(dto -> new UuidFromPair(dto.getUuid(), fromDatesByProjectKey.get(dto.getKey())))
       .toList();

server/sonar-webserver-webapi/src/main/java/org/sonar/server/hotspot/ws/SearchAction.java

@@ -30,6 +30,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import javax.annotation.Nullable;
@@ -87,7 +88,6 @@ import static org.sonar.api.utils.DateUtils.formatDateTime;
 import static org.sonar.api.utils.DateUtils.longToDate;
 import static org.sonar.api.utils.Paging.forPageIndex;
 import static org.sonar.api.web.UserRole.USER;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.newcodeperiod.NewCodePeriodType.REFERENCE_BRANCH;
 import static org.sonar.server.security.SecurityStandards.SANS_TOP_25_INSECURE_INTERACTION;
 import static org.sonar.server.security.SecurityStandards.SANS_TOP_25_POROUS_DEFENSES;
@@ -359,7 +359,7 @@ public class SearchAction implements HotspotsWsAction {
     List<IssueDto> unorderedHotspots = dbClient.issueDao().selectByKeys(dbSession, issueKeys);
     Map<String, IssueDto> hotspotsByKey = unorderedHotspots
       .stream()
-      .collect(uniqueIndex(IssueDto::getKey, unorderedHotspots.size()));
+      .collect(Collectors.toMap(IssueDto::getKey, Function.identity()));
 
     return issueKeys.stream()
       .map(hotspotsByKey::get)
@@ -508,7 +508,7 @@ public class SearchAction implements HotspotsWsAction {
     Map<String, IssueQuery.PeriodStart> leakByProjects = snapshots
       .stream()
       .filter(s -> isNullOrEmpty(s.getPeriodMode()) || !s.getPeriodMode().equals(REFERENCE_BRANCH.name()))
-      .collect(uniqueIndex(SnapshotDto::getRootComponentUuid, s -> new IssueQuery.PeriodStart(longToDate(s.getPeriodDate() == null ? now : s.getPeriodDate()), false)));
+      .collect(Collectors.toMap(SnapshotDto::getRootComponentUuid, s1 -> new IssueQuery.PeriodStart(longToDate(s1.getPeriodDate() == null ? now : s1.getPeriodDate()), false)));
 
     builder.createdAfterByProjectUuids(leakByProjects);
     builder.newCodeOnReferenceByProjectUuids(newCodeReferenceByProjects);

server/sonar-webserver-webapi/src/main/java/org/sonar/server/issue/IssueChangeWSSupport.java

@@ -55,7 +55,6 @@ import static java.util.Collections.emptyMap;
 import static java.util.Optional.empty;
 import static java.util.Optional.ofNullable;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.issue.IssueChangeDto.TYPE_COMMENT;
 import static org.sonar.db.issue.IssueChangeDto.TYPE_FIELD_CHANGE;
 import static org.sonar.server.issue.IssueFieldsSetter.FILE;
@@ -134,12 +133,10 @@ public class IssueChangeWSSupport {
     Multimap<String, IssueChangeDto> unordered = changes.stream()
       .collect(MoreCollectors.index(IssueChangeDto::getIssueKey, t -> t));
     return unordered.asMap().entrySet().stream()
-      .collect(uniqueIndex(
-        Map.Entry::getKey,
-        t -> t.getValue().stream()
-          .map(transform)
-          .sorted(sortingComparator)
-          .toList()));
+      .collect(Collectors.toMap(Map.Entry::getKey, t -> t.getValue().stream()
+        .map(transform)
+        .sorted(sortingComparator)
+        .toList()));
   }
 
   private Map<String, UserDto> loadUsers(DbSession dbSession, Map<String, List<FieldDiffs>> changesByRuleKey,
@@ -165,14 +162,14 @@ public class IssueChangeWSSupport {
     if (missingUsersUuids.isEmpty()) {
       return preloadedUsers.stream()
         .filter(t -> userUuids.contains(t.getUuid()))
-        .collect(uniqueIndex(UserDto::getUuid, userUuids.size()));
+        .collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
     }
 
     return Stream.concat(
         preloadedUsers.stream(),
         dbClient.userDao().selectByUuids(dbSession, missingUsersUuids).stream())
       .filter(t -> userUuids.contains(t.getUuid()))
-      .collect(uniqueIndex(UserDto::getUuid, userUuids.size()));
+      .collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
   }
 
   private Map<String, ComponentDto> loadFiles(DbSession dbSession, Map<String, List<FieldDiffs>> changesByRuleKey, Set<ComponentDto> preloadedComponents) {
@@ -197,14 +194,14 @@ public class IssueChangeWSSupport {
     if (missingFileUuids.isEmpty()) {
       return preloadedComponents.stream()
         .filter(t -> fileUuids.contains(t.uuid()))
-        .collect(uniqueIndex(ComponentDto::uuid, fileUuids.size()));
+        .collect(Collectors.toMap(ComponentDto::uuid, Function.identity()));
     }
 
     return Stream.concat(
         preloadedComponents.stream(),
         dbClient.componentDao().selectByUuids(dbSession, missingFileUuids).stream())
       .filter(t -> fileUuids.contains(t.uuid()))
-      .collect(uniqueIndex(ComponentDto::uuid, fileUuids.size()));
+      .collect(Collectors.toMap(ComponentDto::uuid, Function.identity()));
   }
 
   private Map<String, Boolean> loadUpdatableFlag(Map<String, List<IssueChangeDto>> commentsByIssueKey) {
@@ -218,7 +215,7 @@ public class IssueChangeWSSupport {
 
     return commentsByIssueKey.values().stream()
       .flatMap(Collection::stream)
-      .collect(uniqueIndex(IssueChangeDto::getKey, t -> userUuid.equals(t.getUserUuid())));
+      .collect(Collectors.toMap(IssueChangeDto::getKey, t -> userUuid.equals(t.getUserUuid())));
   }
 
   public Stream<Common.Changelog> formatChangelog(IssueDto dto, FormattingContext formattingContext) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/issue/ws/BulkChangeAction.java

@@ -90,7 +90,6 @@ import static org.sonar.api.rules.RuleType.SECURITY_HOTSPOT;
 import static org.sonar.core.issue.IssueChangeContext.issueChangeContextByUserBuilder;
 import static org.sonar.core.util.Uuids.UUID_EXAMPLE_01;
 import static org.sonar.core.util.Uuids.UUID_EXAMPLE_02;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.es.SearchOptions.MAX_PAGE_SIZE;
 import static org.sonar.server.issue.AbstractChangeTagsAction.TAGS_PARAMETER;
 import static org.sonar.server.issue.AssignAction.ASSIGNEE_PARAMETER;
@@ -385,16 +384,16 @@ public class BulkChangeAction implements IssuesWsAction {
         .toList();
 
       List<ComponentDto> allBranches = getComponents(dbSession, allIssues.stream().map(IssueDto::getProjectUuid).collect(Collectors.toSet()));
-      this.branchComponentByUuid = getAuthorizedComponents(allBranches).stream().collect(uniqueIndex(ComponentDto::uuid, identity()));
+      this.branchComponentByUuid = getAuthorizedComponents(allBranches).stream().collect(toMap(ComponentDto::uuid, identity()));
       this.branchesByProjectUuid = dbClient.branchDao().selectByUuids(dbSession, branchComponentByUuid.keySet()).stream()
-        .collect(uniqueIndex(BranchDto::getUuid, identity()));
+        .collect(toMap(BranchDto::getUuid, identity()));
       this.issues = getAuthorizedIssues(allIssues);
       this.componentsByUuid = getComponents(dbSession,
         issues.stream().map(DefaultIssue::componentUuid).collect(Collectors.toSet())).stream()
-          .collect(uniqueIndex(ComponentDto::uuid, identity()));
+          .collect(toMap(ComponentDto::uuid, identity()));
       this.rulesByKey = dbClient.ruleDao().selectByKeys(dbSession,
         issues.stream().map(DefaultIssue::ruleKey).collect(Collectors.toSet())).stream()
-        .collect(uniqueIndex(RuleDto::getKey, identity()));
+        .collect(toMap(RuleDto::getKey, identity()));
 
       this.availableActions = actions.stream()
         .filter(action -> propertiesByActions.containsKey(action.key()))

server/sonar-webserver-webapi/src/main/java/org/sonar/server/issue/ws/SearchResponseFormat.java

@@ -27,6 +27,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 import org.sonar.api.resources.Language;
 import org.sonar.api.resources.Languages;
 import org.sonar.api.rule.RuleKey;
@@ -73,7 +74,6 @@ import static java.util.Objects.requireNonNull;
 import static java.util.Optional.ofNullable;
 import static org.sonar.api.resources.Qualifiers.UNIT_TEST_FILE;
 import static org.sonar.api.rule.RuleKey.EXTERNAL_RULE_REPO_PREFIX;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.issue.index.IssueIndex.FACET_ASSIGNED_TO_ME;
 import static org.sonar.server.issue.index.IssueIndex.FACET_PROJECTS;
 import static org.sonar.server.issue.ws.SearchAdditionalField.ACTIONS;
@@ -439,7 +439,7 @@ public class SearchResponseFormat {
       return;
     }
 
-    Map<String, RuleKey> ruleUuidsByRuleKeys = data.getRules().stream().collect(uniqueIndex(RuleDto::getUuid, RuleDto::getKey));
+    Map<String, RuleKey> ruleUuidsByRuleKeys = data.getRules().stream().collect(Collectors.toMap(RuleDto::getUuid, RuleDto::getKey));
     Common.Facet.Builder wsFacet = wsFacets.addFacetsBuilder();
     wsFacet.setProperty(PARAM_RULES);
     facet.forEach((ruleUuid, count) -> wsFacet.addValuesBuilder()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/issue/ws/SearchResponseLoader.java

@@ -34,7 +34,6 @@ import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.sonar.api.rules.RuleType;
 import org.sonar.core.issue.DefaultIssue;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.component.BranchDto;
@@ -226,7 +225,7 @@ public class SearchResponseLoader {
       Map<String, ComponentDto> componentsByProjectUuid = result.getComponents()
         .stream()
         .filter(ComponentDto::isRootProject)
-        .collect(MoreCollectors.uniqueIndex(ComponentDto::branchUuid));
+        .collect(Collectors.toMap(ComponentDto::branchUuid, Function.identity()));
       for (IssueDto issueDto : result.getIssues()) {
         // so that IssueDto can be used.
         if (fields.contains(ACTIONS)) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/measure/live/LiveMeasureComputerImpl.java

@@ -26,6 +26,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import org.slf4j.LoggerFactory;
 import org.sonar.api.config.Configuration;
@@ -49,7 +51,6 @@ import static java.util.Collections.emptyList;
 import static java.util.Collections.singleton;
 import static java.util.stream.Collectors.groupingBy;
 import static org.sonar.api.measures.CoreMetrics.ALERT_STATUS_KEY;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 public class LiveMeasureComputerImpl implements LiveMeasureComputer {
 
@@ -112,7 +113,7 @@ public class LiveMeasureComputerImpl implements LiveMeasureComputer {
 
   private MeasureMatrix loadMeasureMatrix(DbSession dbSession, Set<String> componentUuids, QualityGate qualityGate) {
     Collection<String> metricKeys = getKeysOfAllInvolvedMetrics(qualityGate);
-    Map<String, MetricDto> metricsPerUuid = dbClient.metricDao().selectByKeys(dbSession, metricKeys).stream().collect(uniqueIndex(MetricDto::getUuid));
+    Map<String, MetricDto> metricsPerUuid = dbClient.metricDao().selectByKeys(dbSession, metricKeys).stream().collect(Collectors.toMap(MetricDto::getUuid, Function.identity()));
     List<LiveMeasureDto> measures = dbClient.liveMeasureDao().selectByComponentUuidsAndMetricUuids(dbSession, componentUuids, metricsPerUuid.keySet());
     return new MeasureMatrix(componentUuids, metricsPerUuid.values(), measures);
   }

server/sonar-webserver-webapi/src/main/java/org/sonar/server/measure/live/LiveQualityGateComputerImpl.java

@@ -25,6 +25,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.OptionalDouble;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.sonar.api.config.Configuration;
@@ -47,8 +48,6 @@ import org.sonar.server.qualitygate.QualityGateEvaluator;
 import org.sonar.server.qualitygate.QualityGateFinder;
 import org.sonar.server.qualitygate.QualityGateFinder.QualityGateData;
 
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
-
 public class LiveQualityGateComputerImpl implements LiveQualityGateComputer {
 
   private final DbClient dbClient;
@@ -66,7 +65,7 @@ public class LiveQualityGateComputerImpl implements LiveQualityGateComputer {
     QualityGateData qg = qGateFinder.getEffectiveQualityGate(dbSession, project);
     Collection<QualityGateConditionDto> conditionDtos = dbClient.gateConditionDao().selectForQualityGate(dbSession, qg.getUuid());
     Set<String> metricUuids = conditionDtos.stream().map(QualityGateConditionDto::getMetricUuid).collect(Collectors.toSet());
-    Map<String, MetricDto> metricsByUuid = dbClient.metricDao().selectByUuids(dbSession, metricUuids).stream().collect(uniqueIndex(MetricDto::getUuid));
+    Map<String, MetricDto> metricsByUuid = dbClient.metricDao().selectByUuids(dbSession, metricUuids).stream().collect(Collectors.toMap(MetricDto::getUuid, Function.identity()));
 
     Stream<Condition> conditions = conditionDtos.stream().map(conditionDto -> {
       String metricKey = metricsByUuid.get(conditionDto.getMetricUuid()).getKey();

server/sonar-webserver-webapi/src/main/java/org/sonar/server/measure/ws/SearchHistoryResponseFactory.java

@@ -23,9 +23,10 @@ import com.google.common.collect.HashBasedTable;
 import com.google.common.collect.Table;
 import java.util.Map;
 import java.util.Optional;
+import java.util.function.Function;
 import java.util.function.UnaryOperator;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.component.SnapshotDto;
 import org.sonar.db.measure.MeasureDto;
 import org.sonar.db.metric.MetricDto;
@@ -60,8 +61,8 @@ class SearchHistoryResponseFactory {
   }
 
   private UnaryOperator<SearchHistoryResponse.Builder> addMeasures() {
-    Map<String, MetricDto> metricsByUuid = result.getMetrics().stream().collect(MoreCollectors.uniqueIndex(MetricDto::getUuid));
-    Map<String, SnapshotDto> analysesByUuid = result.getAnalyses().stream().collect(MoreCollectors.uniqueIndex(SnapshotDto::getUuid));
+    Map<String, MetricDto> metricsByUuid = result.getMetrics().stream().collect(Collectors.toMap(MetricDto::getUuid, Function.identity()));
+    Map<String, SnapshotDto> analysesByUuid = result.getAnalyses().stream().collect(Collectors.toMap(SnapshotDto::getUuid, Function.identity()));
     Table<MetricDto, SnapshotDto, MeasureDto> measuresByMetricByAnalysis = HashBasedTable.create(result.getMetrics().size(), result.getAnalyses().size());
     result.getMeasures().forEach(m -> measuresByMetricByAnalysis.put(metricsByUuid.get(m.getMetricUuid()), analysesByUuid.get(m.getAnalysisUuid()), m));
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/notification/ws/ListAction.java

@@ -34,7 +34,6 @@ import org.sonar.api.server.ws.Request;
 import org.sonar.api.server.ws.Response;
 import org.sonar.api.server.ws.WebService;
 import org.sonar.api.web.UserRole;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.entity.EntityDto;
@@ -163,7 +162,7 @@ public class ListAction implements NotificationsWsAction {
     return dbClient.entityDao().selectByUuids(dbSession, entityUuids)
       .stream()
       .filter(c -> authorizedProjectUuids.contains(c.getUuid()))
-      .collect(MoreCollectors.uniqueIndex(EntityDto::getUuid));
+      .collect(Collectors.toMap(EntityDto::getUuid, Function.identity()));
   }
 
   private static Function<PropertyDto, Notification> toWsNotification(Notification.Builder notification, Map<String, EntityDto> projectsByUuid) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/project/ws/SearchAction.java

@@ -31,7 +31,6 @@ import org.sonar.api.server.ws.Response;
 import org.sonar.api.server.ws.WebService;
 import org.sonar.api.server.ws.WebService.Param;
 import org.sonar.api.utils.Paging;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DatabaseUtils;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
@@ -166,7 +165,7 @@ public class SearchAction implements ProjectsWsAction {
         .collect(Collectors.toMap(ProjectLastAnalysisDateDto::getProjectUuid, ProjectLastAnalysisDateDto::getDate));
       Map<String, SnapshotDto> snapshotsByComponentUuid = dbClient.snapshotDao()
         .selectLastAnalysesByRootComponentUuids(dbSession, componentUuids).stream()
-        .collect(MoreCollectors.uniqueIndex(SnapshotDto::getRootComponentUuid, identity()));
+        .collect(Collectors.toMap(SnapshotDto::getRootComponentUuid, identity()));
 
       return buildResponse(components, snapshotsByComponentUuid, lastAnalysisDateByComponentUuid, projectUuidByComponentUuid, paging);
     }

server/sonar-webserver-webapi/src/main/java/org/sonar/server/project/ws/SearchMyProjectsData.java

@@ -35,7 +35,6 @@ import org.sonar.db.project.ProjectDto;
 import static com.google.common.collect.ImmutableList.copyOf;
 import static java.util.Objects.requireNonNull;
 import static java.util.function.Function.identity;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 class SearchMyProjectsData {
 
@@ -50,7 +49,7 @@ class SearchMyProjectsData {
     this.projects = copyOf(builder.projects);
     this.branchUuidByProjectUuids = buildBranchUuidByProjectUuidMap(builder.branches);
     this.projectLinksByProjectUuid = buildProjectLinks(builder.projectLinks);
-    this.snapshotsByComponentUuid =builder.snapshots.stream().collect(uniqueIndex(SnapshotDto::getRootComponentUuid, identity()));
+    this.snapshotsByComponentUuid =builder.snapshots.stream().collect(Collectors.toMap(SnapshotDto::getRootComponentUuid, identity()));
     this.qualityGateStatuses = buildQualityGateStatuses(builder.qualityGates);
     this.totalNbOfProject = builder.totalNbOfProjects;
   }

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualitygate/QualityGateCaycChecker.java

@@ -24,6 +24,8 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
 import org.sonar.api.measures.Metric;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
@@ -39,7 +41,6 @@ import static org.sonar.api.measures.CoreMetrics.NEW_MAINTAINABILITY_RATING;
 import static org.sonar.api.measures.CoreMetrics.NEW_RELIABILITY_RATING;
 import static org.sonar.api.measures.CoreMetrics.NEW_SECURITY_HOTSPOTS_REVIEWED;
 import static org.sonar.api.measures.CoreMetrics.NEW_SECURITY_RATING;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.qualitygate.QualityGateCaycStatus.COMPLIANT;
 import static org.sonar.server.qualitygate.QualityGateCaycStatus.NON_COMPLIANT;
 import static org.sonar.server.qualitygate.QualityGateCaycStatus.OVER_COMPLIANT;
@@ -73,7 +74,7 @@ public class QualityGateCaycChecker {
   public QualityGateCaycStatus checkCaycCompliant(DbSession dbSession, String qualityGateUuid) {
     var conditionsByMetricId = dbClient.gateConditionDao().selectForQualityGate(dbSession, qualityGateUuid)
       .stream()
-      .collect(uniqueIndex(QualityGateConditionDto::getMetricUuid));
+      .collect(Collectors.toMap(QualityGateConditionDto::getMetricUuid, Function.identity()));
 
     if (conditionsByMetricId.size() < CAYC_METRICS.size()) {
       return NON_COMPLIANT;

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualitygate/ws/SearchGroupsAction.java

@@ -21,11 +21,11 @@ package org.sonar.server.qualitygate.ws;
 
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.server.ws.Request;
 import org.sonar.api.server.ws.Response;
 import org.sonar.api.server.ws.WebService;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualitygate.QualityGateDto;
@@ -105,7 +105,7 @@ public class SearchGroupsAction implements QualityGatesWsAction {
       Map<String, GroupDto> groupsByUuid = dbClient.groupDao().selectByUuids(dbSession,
           groupMemberships.stream().map(SearchGroupMembershipDto::getGroupUuid).toList())
         .stream()
-        .collect(MoreCollectors.uniqueIndex(GroupDto::getUuid));
+        .collect(Collectors.toMap(GroupDto::getUuid, Function.identity()));
       writeProtobuf(
         Qualitygates.SearchGroupsResponse.newBuilder()
           .addAllGroups(groupMemberships.stream()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualitygate/ws/SearchUsersAction.java

@@ -21,6 +21,7 @@ package org.sonar.server.qualitygate.ws;
 
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.server.ws.Request;
 import org.sonar.api.server.ws.Response;
@@ -45,7 +46,6 @@ import static org.sonar.api.server.ws.WebService.Param.TEXT_QUERY;
 import static org.sonar.api.server.ws.WebService.SelectionMode.ALL;
 import static org.sonar.api.server.ws.WebService.SelectionMode.DESELECTED;
 import static org.sonar.api.server.ws.WebService.SelectionMode.fromParam;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.Pagination.forPage;
 import static org.sonar.db.qualitygate.SearchQualityGatePermissionQuery.builder;
 import static org.sonar.db.user.SearchPermissionQuery.ANY;
@@ -108,7 +108,7 @@ public class SearchUsersAction implements QualityGatesWsAction {
       List<SearchUserMembershipDto> usersMembership = dbClient.qualityGateUserPermissionDao().selectByQuery(dbSession, query,
         forPage(wsRequest.getPage()).andSize(wsRequest.getPageSize()));
       Map<String, UserDto> usersById = dbClient.userDao().selectByUuids(dbSession, usersMembership.stream().map(SearchUserMembershipDto::getUserUuid).toList())
-        .stream().collect(uniqueIndex(UserDto::getUuid));
+        .stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
       writeProtobuf(
         SearchUsersResponse.newBuilder()
           .addAllUsers(usersMembership.stream()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualitygate/ws/ShowAction.java

@@ -41,7 +41,6 @@ import org.sonarqube.ws.Qualitygates.ShowWsResponse;
 
 import static com.google.common.base.Preconditions.checkState;
 import static java.util.Optional.ofNullable;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.qualitygate.ws.QualityGatesWsParameters.PARAM_NAME;
 import static org.sonar.server.ws.WsUtils.writeProtobuf;
 
@@ -103,7 +102,7 @@ public class ShowAction implements QualityGatesWsAction {
 
   private Map<String, MetricDto> getMetricsByUuid(DbSession dbSession, Collection<QualityGateConditionDto> conditions) {
     Set<String> metricUuids = conditions.stream().map(QualityGateConditionDto::getMetricUuid).collect(Collectors.toSet());
-    return dbClient.metricDao().selectByUuids(dbSession, metricUuids).stream().filter(MetricDto::isEnabled).collect(uniqueIndex(MetricDto::getUuid));
+    return dbClient.metricDao().selectByUuids(dbSession, metricUuids).stream().filter(MetricDto::isEnabled).collect(Collectors.toMap(MetricDto::getUuid, Function.identity()));
   }
 
   private ShowWsResponse buildResponse(DbSession dbSession, QualityGateDto qualityGate, QualityGateDto defaultQualityGate, Collection<QualityGateConditionDto> conditions,

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/QProfileExporters.java

@@ -31,6 +31,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import org.apache.commons.lang.ArrayUtils;
@@ -46,7 +47,6 @@ import org.sonar.api.rules.RuleFinder;
 import org.sonar.api.rules.RulePriority;
 import org.sonar.api.server.ServerSide;
 import org.sonar.api.utils.ValidationMessages;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualityprofile.ActiveRuleDto;
@@ -167,7 +167,7 @@ public class QProfileExporters {
   private List<ActiveRuleChange> importProfile(QProfileDto profile, RulesProfile definition, DbSession dbSession) {
     Map<RuleKey, RuleDto> rulesByRuleKey = dbClient.ruleDao().selectAll(dbSession)
       .stream()
-      .collect(MoreCollectors.uniqueIndex(RuleDto::getKey));
+      .collect(Collectors.toMap(RuleDto::getKey, Function.identity()));
     List<ActiveRule> activeRules = definition.getActiveRules();
     List<RuleActivation> activations = activeRules.stream()
       .map(activeRule -> toRuleActivation(activeRule, rulesByRuleKey))
@@ -200,7 +200,7 @@ public class QProfileExporters {
     }
     String severity = activeRule.getSeverity().name();
     Map<String, String> params = activeRule.getActiveRuleParams().stream()
-      .collect(MoreCollectors.uniqueIndex(ActiveRuleParam::getKey, ActiveRuleParam::getValue));
+      .collect(Collectors.toMap(ActiveRuleParam::getKey, ActiveRuleParam::getValue));
     return RuleActivation.create(ruleDto.getUuid(), severity, params);
   }
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/RegisterQualityProfiles.java

@@ -39,7 +39,6 @@ import org.sonar.api.utils.System2;
 import org.sonar.api.utils.log.Logger;
 import org.sonar.api.utils.log.Loggers;
 import org.sonar.api.utils.log.Profiler;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualityprofile.DefaultQProfileDto;
@@ -130,7 +129,7 @@ public class RegisterQualityProfiles implements Startable {
 
   private Map<QProfileName, RulesProfileDto> loadPersistedProfiles(DbSession dbSession) {
     return dbClient.qualityProfileDao().selectBuiltInRuleProfiles(dbSession).stream()
-      .collect(MoreCollectors.uniqueIndex(rp -> new QProfileName(rp.getLanguage(), rp.getName())));
+      .collect(toMap(rp -> new QProfileName(rp.getLanguage(), rp.getName()), Function.identity()));
   }
 
   private void create(DbSession dbSession, DbSession batchDbSession, BuiltInQProfile builtIn) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/builtin/BuiltInQProfileInsertImpl.java

@@ -28,6 +28,7 @@ import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import javax.annotation.Nullable;
 import org.sonar.api.rule.RuleKey;
@@ -35,7 +36,6 @@ import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition;
 import org.sonar.api.server.rule.RuleParamType;
 import org.sonar.api.utils.System2;
 import org.sonar.core.util.UuidFactory;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualityprofile.ActiveRuleDto;
@@ -152,7 +152,7 @@ public class BuiltInQProfileInsertImpl implements BuiltInQProfileInsert {
 
   private List<ActiveRuleParamDto> insertActiveRuleParams(DbSession session, BuiltInQProfile.ActiveRule activeRule, ActiveRuleDto activeRuleDto) {
     Map<String, String> valuesByParamKey = activeRule.getParams().stream()
-      .collect(MoreCollectors.uniqueIndex(BuiltInQualityProfilesDefinition.OverriddenParam::key, BuiltInQualityProfilesDefinition.OverriddenParam::overriddenValue));
+      .collect(Collectors.toMap(BuiltInQualityProfilesDefinition.OverriddenParam::key, BuiltInQualityProfilesDefinition.OverriddenParam::overriddenValue));
     List<ActiveRuleParamDto> rules = ruleRepository.getRuleParams(activeRule.getRuleKey()).stream()
       .map(param -> createParamDto(param, Optional.ofNullable(valuesByParamKey.get(param.getName())).orElse(param.getDefaultValue())))
       .filter(Objects::nonNull)

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/builtin/BuiltInQProfileRepositoryImpl.java

@@ -133,9 +133,7 @@ public class BuiltInQProfileRepositoryImpl implements BuiltInQProfileRepository
     Map<String, List<BuiltInQProfile.Builder>> buildersByLanguage = rulesProfilesByLanguage
       .entrySet()
       .stream()
-      .collect(MoreCollectors.uniqueIndex(
-        Map.Entry::getKey,
-        rulesProfilesByLanguageAndName -> toQualityProfileBuilders(rulesProfilesByLanguageAndName, rulesByRuleKey)));
+      .collect(Collectors.toMap(Map.Entry::getKey, rulesProfilesByLanguageAndName -> toQualityProfileBuilders(rulesProfilesByLanguageAndName, rulesByRuleKey)));
     return buildersByLanguage
       .entrySet()
       .stream()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/builtin/BuiltInQProfileUpdateImpl.java

@@ -27,7 +27,6 @@ import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import org.sonar.api.server.profile.BuiltInQualityProfilesDefinition;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualityprofile.ActiveRuleDto;
@@ -90,7 +89,7 @@ public class BuiltInQProfileUpdateImpl implements BuiltInQProfileUpdate {
 
   private static RuleActivation convert(BuiltInQProfile.ActiveRule ar) {
     Map<String, String> params = ar.getParams().stream()
-      .collect(MoreCollectors.uniqueIndex(BuiltInQualityProfilesDefinition.OverriddenParam::key, BuiltInQualityProfilesDefinition.OverriddenParam::overriddenValue));
+      .collect(Collectors.toMap(BuiltInQualityProfilesDefinition.OverriddenParam::key, BuiltInQualityProfilesDefinition.OverriddenParam::overriddenValue));
     return RuleActivation.create(ar.getRuleUuid(), ar.getSeverity(), params);
   }
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/builtin/RuleActivationContext.java

@@ -25,6 +25,7 @@ import java.util.Collection;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import org.sonar.api.rule.RuleKey;
@@ -41,7 +42,6 @@ import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkState;
 import static java.util.Objects.requireNonNull;
 import static org.sonar.core.util.stream.MoreCollectors.index;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.exceptions.BadRequestException.checkRequest;
 
 /**
@@ -312,7 +312,7 @@ public class RuleActivationContext {
 
     private RuleWrapper(RuleDto rule, Collection<RuleParamDto> params) {
       this.rule = rule;
-      this.paramsByKey = params.stream().collect(uniqueIndex(RuleParamDto::getName));
+      this.paramsByKey = params.stream().collect(Collectors.toMap(RuleParamDto::getName, Function.identity()));
     }
 
     public RuleDto get() {
@@ -341,7 +341,7 @@ public class RuleActivationContext {
 
     private ActiveRuleWrapper(ActiveRuleDto activeRule, Collection<ActiveRuleParamDto> params) {
       this.activeRule = activeRule;
-      this.paramsByKey = params.stream().collect(uniqueIndex(ActiveRuleParamDto::getKey));
+      this.paramsByKey = params.stream().collect(Collectors.toMap(ActiveRuleParamDto::getKey, Function.identity()));
     }
 
     ActiveRuleDto get() {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/ws/ChangelogAction.java

@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import javax.annotation.CheckForNull;
 import org.sonar.api.resources.Languages;
@@ -46,7 +47,6 @@ import org.sonar.db.user.UserDto;
 
 import static org.sonar.api.utils.DateUtils.parseEndingDateOrDateTime;
 import static org.sonar.api.utils.DateUtils.parseStartingDateOrDateTime;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.server.es.SearchOptions.MAX_PAGE_SIZE;
 import static org.sonarqube.ws.client.qualityprofile.QualityProfileWsParameters.PARAM_SINCE;
 import static org.sonarqube.ws.client.qualityprofile.QualityProfileWsParameters.PARAM_TO;
@@ -126,7 +126,7 @@ public class ChangelogAction implements QProfileWsAction {
     return dbClient.userDao()
       .selectByUuids(dbSession, userUuids)
       .stream()
-      .collect(uniqueIndex(UserDto::getUuid));
+      .collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
   }
 
   private Map<String, RuleDto> getRulesByRuleUuids(DbSession dbSession, List<Change> changes) {
@@ -137,7 +137,7 @@ public class ChangelogAction implements QProfileWsAction {
     return dbClient.ruleDao()
       .selectByUuids(dbSession, Lists.newArrayList(ruleUuids))
       .stream()
-      .collect(uniqueIndex(RuleDto::getUuid));
+      .collect(Collectors.toMap(RuleDto::getUuid, Function.identity()));
   }
 
   private static void writeResponse(JsonWriter json, int total, int page, int pageSize, List<Change> changelogs,

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/ws/SearchAction.java

@@ -38,7 +38,6 @@ import org.sonar.api.server.ws.Request;
 import org.sonar.api.server.ws.Response;
 import org.sonar.api.server.ws.WebService;
 import org.sonar.api.server.ws.WebService.NewAction;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.project.ProjectDto;
@@ -217,7 +216,7 @@ public class SearchAction implements QProfileWsAction {
     }
     Map<String, QProfileDto> effectiveProfiles = defaultProfiles.stream().collect(Collectors.toMap(QProfileDto::getLanguage, identity()));
     effectiveProfiles.putAll(dbClient.qualityProfileDao().selectAssociatedToProjectAndLanguages(dbSession, project, getLanguageKeys()).stream()
-      .collect(MoreCollectors.uniqueIndex(QProfileDto::getLanguage)));
+      .collect(Collectors.toMap(QProfileDto::getLanguage, identity())));
     return p -> Objects.equals(p.getKee(), effectiveProfiles.get(p.getLanguage()).getKee());
   }
 

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/ws/SearchGroupsAction.java

@@ -22,13 +22,13 @@ package org.sonar.server.qualityprofile.ws;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.resources.Language;
 import org.sonar.api.resources.Languages;
 import org.sonar.api.server.ws.Request;
 import org.sonar.api.server.ws.Response;
 import org.sonar.api.server.ws.WebService;
-import org.sonar.core.util.stream.MoreCollectors;
 import org.sonar.db.DbClient;
 import org.sonar.db.DbSession;
 import org.sonar.db.qualityprofile.QProfileDto;
@@ -118,7 +118,7 @@ public class SearchGroupsAction implements QProfileWsAction {
       Map<String, GroupDto> groupsByUuid = dbClient.groupDao().selectByUuids(dbSession,
         groupMemberships.stream().map(SearchGroupMembershipDto::getGroupUuid).toList())
         .stream()
-        .collect(MoreCollectors.uniqueIndex(GroupDto::getUuid));
+        .collect(Collectors.toMap(GroupDto::getUuid, Function.identity()));
       writeProtobuf(
         Qualityprofiles.SearchGroupsResponse.newBuilder()
           .addAllGroups(groupMemberships.stream()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/qualityprofile/ws/SearchUsersAction.java

@@ -23,6 +23,7 @@ import com.google.common.collect.ImmutableMap;
 import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.resources.Language;
 import org.sonar.api.resources.Languages;
@@ -49,7 +50,6 @@ import static org.sonar.api.server.ws.WebService.Param.TEXT_QUERY;
 import static org.sonar.api.server.ws.WebService.SelectionMode.ALL;
 import static org.sonar.api.server.ws.WebService.SelectionMode.DESELECTED;
 import static org.sonar.api.server.ws.WebService.SelectionMode.fromParam;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.Pagination.forPage;
 import static org.sonar.db.qualityprofile.SearchQualityProfilePermissionQuery.ANY;
 import static org.sonar.db.qualityprofile.SearchQualityProfilePermissionQuery.IN;
@@ -122,7 +122,7 @@ public class SearchUsersAction implements QProfileWsAction {
       List<SearchUserMembershipDto> usersMembership = dbClient.qProfileEditUsersDao().selectByQuery(dbSession, query,
         forPage(wsRequest.getPage()).andSize(wsRequest.getPageSize()));
       Map<String, UserDto> usersById = dbClient.userDao().selectByUuids(dbSession, usersMembership.stream().map(SearchUserMembershipDto::getUserUuid).toList())
-        .stream().collect(uniqueIndex(UserDto::getUuid));
+        .stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
       writeProtobuf(
         SearchUsersResponse.newBuilder()
           .addAllUsers(usersMembership.stream()

server/sonar-webserver-webapi/src/main/java/org/sonar/server/rule/ws/ActiveRuleCompleter.java

@@ -55,7 +55,6 @@ import org.sonarqube.ws.Rules.SearchResponse;
 import static com.google.common.base.Strings.nullToEmpty;
 import static java.util.Collections.singletonList;
 import static java.util.Optional.ofNullable;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 /**
  * Add details about active rules to api/rules/search and api/rules/show
@@ -86,7 +85,7 @@ public class ActiveRuleCompleter {
       // Load details of active rules on the selected profile
       List<OrgActiveRuleDto> activeRules = dbClient.activeRuleDao().selectByProfile(dbSession, profile);
       Map<RuleKey, OrgActiveRuleDto> activeRuleByRuleKey = activeRules.stream()
-        .collect(uniqueIndex(ActiveRuleDto::getRuleKey));
+        .collect(Collectors.toMap(ActiveRuleDto::getRuleKey, Function.identity()));
       ListMultimap<ActiveRuleKey, ActiveRuleParamDto> activeRuleParamsByActiveRuleKey = loadParams(dbSession, activeRules);
 
       for (RuleDto rule : rules) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/rule/ws/RuleWsSupport.java

@@ -24,6 +24,7 @@ import java.util.List;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.stream.Collectors;
 import org.sonar.api.rule.RuleStatus;
 import org.sonar.api.rule.Severity;
@@ -45,7 +46,6 @@ import static org.sonar.api.server.ws.WebService.Param.SORT;
 import static org.sonar.api.server.ws.WebService.Param.TEXT_QUERY;
 import static org.sonar.core.util.Uuids.UUID_EXAMPLE_01;
 import static org.sonar.core.util.Uuids.UUID_EXAMPLE_02;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.permission.GlobalPermission.ADMINISTER_QUALITY_PROFILES;
 import static org.sonar.server.rule.ws.RulesWsParameters.PARAM_ACTIVATION;
 import static org.sonar.server.rule.ws.RulesWsParameters.PARAM_ACTIVE_SEVERITIES;
@@ -88,7 +88,7 @@ public class RuleWsSupport {
 
   Map<String, UserDto> getUsersByUuid(DbSession dbSession, List<RuleDto> rules) {
     Set<String> userUuids = rules.stream().map(RuleDto::getNoteUserUuid).filter(Objects::nonNull).collect(Collectors.toSet());
-    return dbClient.userDao().selectByUuids(dbSession, userUuids).stream().collect(uniqueIndex(UserDto::getUuid));
+    return dbClient.userDao().selectByUuids(dbSession, userUuids).stream().collect(Collectors.toMap(UserDto::getUuid, Function.identity()));
   }
 
   public static void defineGenericRuleSearchParameters(WebService.NewAction action) {

server/sonar-webserver-webapi/src/main/java/org/sonar/server/ui/ws/ComponentAction.java

@@ -25,7 +25,9 @@ import java.util.List;
 import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
+import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 import javax.annotation.Nullable;
 import org.sonar.api.config.Configuration;
 import org.sonar.api.resources.Qualifiers;
@@ -67,7 +69,6 @@ import static org.sonar.api.measures.CoreMetrics.QUALITY_PROFILES_KEY;
 import static org.sonar.api.utils.DateUtils.formatDateTime;
 import static org.sonar.api.web.UserRole.ADMIN;
 import static org.sonar.api.web.UserRole.USER;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.db.permission.GlobalPermission.ADMINISTER_QUALITY_GATES;
 import static org.sonar.db.permission.GlobalPermission.ADMINISTER_QUALITY_PROFILES;
 import static org.sonar.server.user.AbstractUserSession.insufficientPrivilegesException;
@@ -253,7 +254,7 @@ public class ComponentAction implements NavigationWsAction {
       .orElse(emptySortedSet());
     Map<String, QProfileDto> dtoByQPKey = dbClient.qualityProfileDao().selectByUuids(dbSession, qualityProfiles.stream().map(QualityProfile::getQpKey).toList())
       .stream()
-      .collect(uniqueIndex(QProfileDto::getKee));
+      .collect(Collectors.toMap(QProfileDto::getKee, Function.identity()));
     json.name("qualityProfiles").beginArray();
     qualityProfiles.forEach(qp -> writeToJson(json, qp, !dtoByQPKey.containsKey(qp.getQpKey())));
     json.endArray();

server/sonar-webserver-webapi/src/test/java/org/sonar/server/ce/queue/BranchSupportTest.java

@@ -24,6 +24,7 @@ import com.tngtech.java.junit.dataprovider.DataProviderRunner;
 import java.util.Collections;
 import java.util.Map;
 import java.util.Random;
+import java.util.stream.Collectors;
 import java.util.stream.IntStream;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -38,7 +39,6 @@ import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 
 @RunWith(DataProviderRunner.class)
 public class BranchSupportTest {
@@ -109,6 +109,6 @@ public class BranchSupportTest {
   }
 
   private static Map<String, String> newRandomNonEmptyMap() {
-    return IntStream.range(0, 1 + new Random().nextInt(10)).boxed().collect(uniqueIndex(i -> "key_" + i, i -> "val_" + i));
+    return IntStream.range(0, 1 + new Random().nextInt(10)).boxed().collect(Collectors.toMap(i -> "key_" + i, i1 -> "val_" + i1));
   }
 }

sonar-core/src/main/java/org/sonar/core/util/stream/MoreCollectors.java

@@ -20,14 +20,11 @@
 package org.sonar.core.util.stream;
 
 import com.google.common.collect.ImmutableListMultimap;
-import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSetMultimap;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.function.BiConsumer;
 import java.util.function.BinaryOperator;
 import java.util.function.Function;
-import java.util.function.Supplier;
 import java.util.stream.Collector;
 import java.util.stream.Stream;
 
@@ -35,7 +32,6 @@ import static java.util.Objects.requireNonNull;
 
 public final class MoreCollectors {
 
-  private static final int DEFAULT_HASHMAP_CAPACITY = 0;
   private static final String KEY_FUNCTION_CANT_RETURN_NULL_MESSAGE = "Key function can't return null";
   private static final String VALUE_FUNCTION_CANT_RETURN_NULL_MESSAGE = "Value function can't return null";
 
@@ -43,126 +39,6 @@ public final class MoreCollectors {
     // prevents instantiation
   }
 
-
-  /**
-   * Creates an {@link ImmutableMap} from the stream where the values are the values in the stream and the keys are the
-   * result of the provided {@link Function keyFunction} applied to each value in the stream.
-   *
-   * <p>
-   * The {@link Function keyFunction} must return a unique (according to the key's type {@link Object#equals(Object)}
-   * and/or {@link Comparable#compareTo(Object)} implementations) value for each of them, otherwise a
-   * {@link IllegalArgumentException} will be thrown.
-   * </p>
-   *
-   * <p>
-   * {@link Function keyFunction} can't return {@code null}, otherwise a {@link NullPointerException} will be thrown.
-   * </p>
-   *
-   * @throws NullPointerException if {@code keyFunction} is {@code null}.
-   * @throws NullPointerException if result of {@code keyFunction} is {@code null}.
-   * @throws IllegalArgumentException if {@code keyFunction} returns the same value for multiple entries in the stream.
-   */
-  public static <K, E> Collector<E, Map<K, E>, ImmutableMap<K, E>> uniqueIndex(Function<? super E, K> keyFunction) {
-    return uniqueIndex(keyFunction, Function.identity());
-  }
-
-  /**
-   * Same as {@link #uniqueIndex(Function)} but using an underlying {@link Map} initialized with a capacity for the
-   * specified expected size.
-   *
-   * <p>Note: using this method with a parallel stream will likely not have the expected memory usage benefit as all
-   * processing threads will use a Map with a capacity large enough for the final size.</p>
-   *
-   * <p>
-   * {@link Function keyFunction} can't return {@code null}, otherwise a {@link NullPointerException} will be thrown.
-   * </p>
-   *
-   * @throws NullPointerException if {@code keyFunction} is {@code null}.
-   * @throws NullPointerException if result of {@code keyFunction} is {@code null}.
-   * @throws IllegalArgumentException if {@code keyFunction} returns the same value for multiple entries in the stream.
-   * @see #uniqueIndex(Function)
-   */
-  public static <K, E> Collector<E, Map<K, E>, ImmutableMap<K, E>> uniqueIndex(Function<? super E, K> keyFunction, int expectedSize) {
-    return uniqueIndex(keyFunction, Function.identity(), expectedSize);
-  }
-
-  /**
-   * Creates an {@link ImmutableMap} from the stream where the values are the result of {@link Function valueFunction}
-   * applied to the values in the stream and the keys are the result of the provided {@link Function keyFunction}
-   * applied to each value in the stream.
-   *
-   * <p>
-   * The {@link Function keyFunction} must return a unique (according to the key's type {@link Object#equals(Object)}
-   * and/or {@link Comparable#compareTo(Object)} implementations) value for each of them, otherwise a
-   * {@link IllegalArgumentException} will be thrown.
-   * </p>
-   *
-   * <p>
-   * Neither {@link Function keyFunction} nor {@link Function valueFunction} can return {@code null}, otherwise a
-   * {@link NullPointerException} will be thrown.
-   * </p>
-   *
-   * @throws NullPointerException if {@code keyFunction} or {@code valueFunction} is {@code null}.
-   * @throws NullPointerException if result of {@code keyFunction} or {@code valueFunction} is {@code null}.
-   * @throws IllegalArgumentException if {@code keyFunction} returns the same value for multiple entries in the stream.
-   */
-  public static <K, E, V> Collector<E, Map<K, V>, ImmutableMap<K, V>> uniqueIndex(Function<? super E, K> keyFunction,
-    Function<? super E, V> valueFunction) {
-    return uniqueIndex(keyFunction, valueFunction, DEFAULT_HASHMAP_CAPACITY);
-  }
-
-  /**
-   * Same as {@link #uniqueIndex(Function, Function)} but using an underlying {@link Map} initialized with a capacity
-   * for the specified expected size.
-   *
-   * <p>Note: using this method with a parallel stream will likely not have the expected memory usage benefit as all
-   * processing threads will use a Map with a capacity large enough for the final size.</p>
-   *
-   * <p>
-   * Neither {@link Function keyFunction} nor {@link Function valueFunction} can return {@code null}, otherwise a
-   * {@link NullPointerException} will be thrown.
-   * </p>
-   *
-   * @throws NullPointerException if {@code keyFunction} or {@code valueFunction} is {@code null}.
-   * @throws NullPointerException if result of {@code keyFunction} or {@code valueFunction} is {@code null}.
-   * @throws IllegalArgumentException if {@code keyFunction} returns the same value for multiple entries in the stream.
-   * @see #uniqueIndex(Function, Function)
-   */
-  public static <K, E, V> Collector<E, Map<K, V>, ImmutableMap<K, V>> uniqueIndex(Function<? super E, K> keyFunction,
-    Function<? super E, V> valueFunction, int expectedSize) {
-    verifyKeyAndValueFunctions(keyFunction, valueFunction);
-
-    BiConsumer<Map<K, V>, E> accumulator = (map, element) -> {
-      K key = requireNonNull(keyFunction.apply(element), KEY_FUNCTION_CANT_RETURN_NULL_MESSAGE);
-      V value = requireNonNull(valueFunction.apply(element), VALUE_FUNCTION_CANT_RETURN_NULL_MESSAGE);
-
-      putAndFailOnDuplicateKey(map, key, value);
-    };
-    BinaryOperator<Map<K, V>> merger = (m1, m2) -> {
-      for (Map.Entry<K, V> entry : m2.entrySet()) {
-        putAndFailOnDuplicateKey(m1, entry.getKey(), entry.getValue());
-      }
-      return m1;
-    };
-    return Collector.of(
-      newHashMapSupplier(expectedSize),
-      accumulator,
-      merger,
-      ImmutableMap::copyOf,
-      Collector.Characteristics.UNORDERED);
-  }
-
-  private static <K, V> Supplier<Map<K, V>> newHashMapSupplier(int expectedSize) {
-    return () -> expectedSize == DEFAULT_HASHMAP_CAPACITY ? new HashMap<>() : new HashMap<>(expectedSize);
-  }
-
-  private static <K, V> void putAndFailOnDuplicateKey(Map<K, V> map, K key, V value) {
-    V existingValue = map.put(key, value);
-    if (existingValue != null) {
-      throw new IllegalArgumentException(String.format("Duplicate key %s", key));
-    }
-  }
-
   /**
    * Creates an {@link com.google.common.collect.ImmutableListMultimap} from the stream where the values are the values
    * in the stream and the keys are the result of the provided {@link Function keyFunction} applied to each value in the

sonar-core/src/test/java/org/sonar/core/util/stream/MoreCollectorsTest.java

@@ -35,9 +35,7 @@ import org.junit.Test;
 import static java.util.function.Function.identity;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
-import static org.assertj.core.api.Assertions.entry;
 import static org.sonar.core.util.stream.MoreCollectors.index;
-import static org.sonar.core.util.stream.MoreCollectors.uniqueIndex;
 import static org.sonar.core.util.stream.MoreCollectors.unorderedFlattenIndex;
 import static org.sonar.core.util.stream.MoreCollectors.unorderedIndex;
 
@@ -60,190 +58,6 @@ public class MoreCollectorsTest {
   private static final List<MyObj> LIST = Arrays.asList(MY_OBJ_1_A, MY_OBJ_2_B, MY_OBJ_3_C);
   private static final List<MyObj2> LIST2 = Arrays.asList(MY_OBJ2_1_A_X, MY_OBJ2_2_B, MY_OBJ2_3_C);
 
-  @Test
-  public void uniqueIndex_empty_stream_returns_empty_map() {
-    assertThat(Stream.<MyObj>empty().collect(uniqueIndex(MyObj::getId))).isEmpty();
-    assertThat(Stream.<MyObj>empty().collect(uniqueIndex(MyObj::getId, 6))).isEmpty();
-    assertThat(Stream.<MyObj>empty().collect(uniqueIndex(MyObj::getId, MyObj::getText))).isEmpty();
-    assertThat(Stream.<MyObj>empty().collect(uniqueIndex(MyObj::getId, MyObj::getText, 10))).isEmpty();
-  }
-
-  @Test
-  public void uniqueIndex_fails_when_there_is_duplicate_keys() {
-    Stream<MyObj> stream = LIST_WITH_DUPLICATE_ID.stream();
-
-    assertThatThrownBy(() -> stream.collect(uniqueIndex(MyObj::getId)))
-      .isInstanceOf(IllegalArgumentException.class)
-      .hasMessage("Duplicate key 1");
-  }
-
-  @Test
-  public void uniqueIndex_with_expected_size_fails_when_there_is_duplicate_keys() {
-    Stream<MyObj> stream = LIST_WITH_DUPLICATE_ID.stream();
-
-    assertThatThrownBy(() -> stream.collect(uniqueIndex(MyObj::getId, 1)))
-      .isInstanceOf(IllegalArgumentException.class)
-      .hasMessage("Duplicate key 1");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_fails_when_there_is_duplicate_keys() {
-    Stream<MyObj> stream = LIST_WITH_DUPLICATE_ID.stream();
-
-    assertThatThrownBy(() -> stream.collect(uniqueIndex(MyObj::getId, MyObj::getText)))
-      .isInstanceOf(IllegalArgumentException.class)
-      .hasMessage("Duplicate key 1");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_fails_when_there_is_duplicate_keys() {
-    Stream<MyObj> stream = LIST_WITH_DUPLICATE_ID.stream();
-
-    assertThatThrownBy(() -> stream.collect(uniqueIndex(MyObj::getId, MyObj::getText, 10)))
-      .isInstanceOf(IllegalArgumentException.class)
-      .hasMessage("Duplicate key 1");
-  }
-
-  @Test
-  public void uniqueIndex_fails_if_key_function_is_null() {
-    assertThatThrownBy(() -> uniqueIndex(null))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_with_expected_size_fails_if_key_function_is_null() {
-    assertThatThrownBy(() -> uniqueIndex(null, 2))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_fails_if_key_function_is_null() {
-    assertThatThrownBy(() -> uniqueIndex(null, MyObj::getText))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_fails_if_key_function_is_null() {
-    assertThatThrownBy(() ->  uniqueIndex(null, MyObj::getText, 9))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_fails_if_value_function_is_null() {
-    assertThatThrownBy(() ->  uniqueIndex(MyObj::getId, null))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Value function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_fails_if_value_function_is_null() {
-    assertThatThrownBy(() ->  uniqueIndex(MyObj::getId, null, 9))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Value function can't be null");
-  }
-
-  @Test
-  public void uniqueIndex_fails_if_key_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(s -> null)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_with_expected_size_fails_if_key_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(s -> null, 90)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_fails_if_key_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(s -> null, MyObj::getText)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_fails_if_key_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(s -> null, MyObj::getText, 9)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Key function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_fails_if_value_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(MyObj::getId, s -> null)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Value function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_fails_if_value_function_returns_null() {
-    assertThatThrownBy(() -> SINGLE_ELEMENT_LIST.stream().collect(uniqueIndex(MyObj::getId, s -> null, 9)))
-      .isInstanceOf(NullPointerException.class)
-      .hasMessage("Value function can't return null");
-  }
-
-  @Test
-  public void uniqueIndex_returns_map() {
-    assertThat(LIST.stream().collect(uniqueIndex(MyObj::getId))).containsOnly(entry(1, MY_OBJ_1_A), entry(2, MY_OBJ_2_B), entry(3, MY_OBJ_3_C));
-  }
-
-  @Test
-  public void uniqueIndex_with_expected_size_returns_map() {
-    assertThat(LIST.stream().collect(uniqueIndex(MyObj::getId, 3))).containsOnly(entry(1, MY_OBJ_1_A), entry(2, MY_OBJ_2_B), entry(3, MY_OBJ_3_C));
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_returns_map() {
-    assertThat(LIST.stream().collect(uniqueIndex(MyObj::getId, MyObj::getText))).containsOnly(entry(1, "A"), entry(2, "B"), entry(3, "C"));
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_returns_map() {
-    assertThat(LIST.stream().collect(uniqueIndex(MyObj::getId, MyObj::getText, 9))).containsOnly(entry(1, "A"), entry(2, "B"), entry(3, "C"));
-  }
-
-  @Test
-  public void uniqueIndex_parallel_stream() {
-    Map<String, String> map = HUGE_LIST.parallelStream().collect(uniqueIndex(identity()));
-    assertThat(map.keySet()).isEqualTo(HUGE_SET);
-    assertThat(map.values()).containsExactlyElementsOf(HUGE_SET);
-  }
-
-  @Test
-  public void uniqueIndex_with_expected_size_parallel_stream() {
-    Map<String, String> map = HUGE_LIST.parallelStream().collect(uniqueIndex(identity(), HUGE_LIST.size()));
-    assertThat(map.keySet()).isEqualTo(HUGE_SET);
-    assertThat(map.values()).containsExactlyElementsOf(HUGE_SET);
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_parallel_stream() {
-    Map<String, String> map = HUGE_LIST.parallelStream().collect(uniqueIndex(identity(), identity()));
-    assertThat(map.keySet()).isEqualTo(HUGE_SET);
-    assertThat(map.values()).containsExactlyElementsOf(HUGE_SET);
-  }
-
-  @Test
-  public void uniqueIndex_with_valueFunction_and_expected_size_parallel_stream() {
-    Map<String, String> map = HUGE_LIST.parallelStream().collect(uniqueIndex(identity(), identity(), HUGE_LIST.size()));
-    assertThat(map.keySet()).isEqualTo(HUGE_SET);
-    assertThat(map.values()).containsExactlyElementsOf(HUGE_SET);
-  }
-
-  @Test
-  public void uniqueIndex_supports_duplicate_keys() {
-    ListMultimap<Integer, String> multimap = LIST_WITH_DUPLICATE_ID.stream().collect(index(MyObj::getId, MyObj::getText));
-
-    assertThat(multimap.keySet()).containsOnly(1, 2);
-    assertThat(multimap.get(1)).containsOnly("A", "C");
-    assertThat(multimap.get(2)).containsOnly("B");
-  }
 
   @Test
   public void index_empty_stream_returns_empty_map() {