add StatelessSession.get() accepting multiple ids

hibernate-reactive-core/src/main/java/org/hibernate/reactive/mutiny/Mutiny.java

@@ -40,6 +40,7 @@
 import jakarta.persistence.CacheRetrieveMode;
 import jakarta.persistence.CacheStoreMode;
 import jakarta.persistence.EntityGraph;
+import jakarta.persistence.FindOption;
 import jakarta.persistence.FlushModeType;
 import jakarta.persistence.LockModeType;
 import jakarta.persistence.Parameter;
@@ -617,6 +618,8 @@ default <T> Uni<T> find(Class<T> entityClass, Object id, LockModeType lockModeTy
 		 * @param ids the identifiers
 		 *
 		 * @return a list of persistent instances and nulls via a {@code Uni}
+		 *
+		 * @see org.hibernate.Session#findMultiple(Class, List, FindOption...)
 		 */
 		<T> Uni<List<T>> find(Class<T> entityClass, Object... ids);
 
@@ -1569,6 +1572,18 @@ interface StatelessSession extends Closeable {
 		 */
 		<T> Uni<T> get(Class<T> entityClass, Object id);
 
+		/**
+		 * Retrieve multiple rows.
+		 *
+		 * @param entityClass The class of the entity to retrieve
+		 * @param ids The ids of the entities to retrieve
+		 *
+		 * @return a list of detached entity instances, via a {@code Uni}
+		 *
+		 * @see org.hibernate.StatelessSession#getMultiple(Class, List)
+		 */
+		<T> Uni<List<T>> get(Class<T> entityClass, Object... ids);
+
 		/**
 		 * Retrieve a row, obtaining the specified lock mode.
 		 *
@@ -1737,6 +1752,24 @@ default <T> Uni<T> get(Class<T> entityClass, Object id, LockModeType lockModeTyp
 		 */
 		<R> SelectionQuery<R> createQuery(CriteriaQuery<R> criteriaQuery);
 
+		/**
+		 * Create an instance of {@link MutationQuery} for the given criteria update.
+		 *
+		 * @param criteriaUpdate The {@link CriteriaUpdate}
+		 *
+		 * @return The {@link MutationQuery} instance for manipulation and execution
+		 */
+		<R> MutationQuery createQuery(CriteriaUpdate<R> criteriaUpdate);
+
+		/**
+		 * Create an instance of {@link MutationQuery} for the given criteria delete.
+		 *
+		 * @param criteriaDelete The {@link CriteriaDelete}
+		 *
+		 * @return The {@link MutationQuery} instance for manipulation and execution
+		 */
+		<R> MutationQuery createQuery(CriteriaDelete<R> criteriaDelete);
+
 		/**
 		 * Insert a row.
 		 *

hibernate-reactive-core/src/main/java/org/hibernate/reactive/mutiny/impl/MutinyStatelessSessionImpl.java

@@ -7,7 +7,9 @@
 
 import io.smallrye.mutiny.Uni;
 import jakarta.persistence.EntityGraph;
+import jakarta.persistence.criteria.CriteriaDelete;
 import jakarta.persistence.criteria.CriteriaQuery;
+import jakarta.persistence.criteria.CriteriaUpdate;
 import org.hibernate.LockMode;
 import org.hibernate.graph.spi.RootGraphImplementor;
 import org.hibernate.reactive.common.ResultSetMapping;
@@ -53,6 +55,11 @@ public <T> Uni<T> get(Class<T> entityClass, Object id) {
 		return uni( () -> delegate.reactiveGet( entityClass, id ) );
 	}
 
+	@Override
+	public <T> Uni<List<T>> get(Class<T> entityClass, Object... ids) {
+		return uni( () -> delegate.reactiveGet( entityClass, ids ) );
+	}
+
 	@Override
 	public <T> Uni<T> get(Class<T> entityClass, Object id, LockMode lockMode) {
 		return uni( () -> delegate.reactiveGet( entityClass, id, lockMode, null ) );
@@ -114,6 +121,16 @@ public <R> SelectionQuery<R> createQuery(CriteriaQuery<R> criteriaQuery) {
 		return new MutinySelectionQueryImpl<>( delegate.createReactiveQuery( criteriaQuery ), factory );
 	}
 
+	@Override
+	public <R> Mutiny.MutationQuery createQuery(CriteriaUpdate<R> criteriaUpdate) {
+		return new MutinyMutationQueryImpl<>( delegate.createReactiveMutationQuery( criteriaUpdate ), factory );
+	}
+
+	@Override
+	public <R> Mutiny.MutationQuery createQuery(CriteriaDelete<R> criteriaDelete) {
+		return new MutinyMutationQueryImpl<>( delegate.createReactiveMutationQuery( criteriaDelete ), factory );
+	}
+
 	@Override
 	public Uni<Void> insert(Object entity) {
 		return uni( () -> delegate.reactiveInsert( entity ) );

hibernate-reactive-core/src/main/java/org/hibernate/reactive/session/ReactiveStatelessSession.java

@@ -10,6 +10,8 @@
 import org.hibernate.reactive.engine.spi.ReactiveSharedSessionContractImplementor;
 
 import jakarta.persistence.EntityGraph;
+
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
 
@@ -26,11 +28,13 @@
 @Incubating
 public interface ReactiveStatelessSession extends ReactiveQueryProducer, ReactiveSharedSessionContractImplementor {
 
-	<T> CompletionStage<T> reactiveGet(Class<? extends T> entityClass, Object id);
+	<T> CompletionStage<T> reactiveGet(Class<T> entityClass, Object id);
+
+	<T> CompletionStage<List<T>> reactiveGet(Class<T> entityClass, Object... id);
 
 	<T> CompletionStage<T> reactiveGet(String entityName, Object id);
 
-	<T> CompletionStage<T> reactiveGet(Class<? extends T> entityClass, Object id, LockMode lockMode, EntityGraph<T> fetchGraph);
+	<T> CompletionStage<T> reactiveGet(Class<T> entityClass, Object id, LockMode lockMode, EntityGraph<T> fetchGraph);
 
 	<T> CompletionStage<T> reactiveGet(String entityName, Object id, LockMode lockMode, EntityGraph<T> fetchGraph);
 

hibernate-reactive-core/src/main/java/org/hibernate/reactive/session/impl/ReactiveStatelessSessionImpl.java

@@ -5,6 +5,8 @@
  */
 package org.hibernate.reactive.session.impl;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.concurrent.CompletableFuture;
 import java.util.concurrent.CompletionStage;
 import java.util.function.Supplier;
@@ -46,6 +48,8 @@
 import org.hibernate.proxy.LazyInitializer;
 import org.hibernate.query.IllegalMutationQueryException;
 import org.hibernate.query.criteria.JpaCriteriaInsert;
+import org.hibernate.query.criteria.JpaCriteriaQuery;
+import org.hibernate.query.criteria.JpaRoot;
 import org.hibernate.query.hql.spi.SqmQueryImplementor;
 import org.hibernate.query.named.NamedResultSetMappingMemento;
 import org.hibernate.query.spi.HqlInterpretation;
@@ -204,17 +208,46 @@ public void checkTransactionNeededForUpdateOperation(String exceptionMessage) {
 	}
 
 	@Override
-	public <T> CompletionStage<T> reactiveGet(Class<? extends T> entityClass, Object id) {
+	public <T> CompletionStage<T> reactiveGet(Class<T> entityClass, Object id) {
 		return reactiveGet( entityClass.getName(), id, LockMode.NONE, null );
 	}
 
+	@Override
+	public <T> CompletionStage<List<T>> reactiveGet(Class<T> entityClass, Object... ids) {
+		checkOpen();
+		for (Object id : ids) {
+			if ( id == null ) {
+				throw new IllegalArgumentException("Null id");
+			}
+		}
+
+		final EntityPersister persister = getEntityPersister( entityClass.getName() );
+
+		final JpaCriteriaQuery<T> query = getCriteriaBuilder().createQuery(entityClass);
+		final JpaRoot<T> from = query.from(entityClass);
+		query.where( from.get( persister.getIdentifierPropertyName() ).in(ids) );
+		return createReactiveQuery(query).getReactiveResultList()
+				.thenApply( resultList -> {
+					final List<Object> idList = new ArrayList<>( resultList.size() );
+					for (T entity : resultList) {
+						idList.add( persister.getIdentifier(entity, this) );
+					}
+					final List<T> list = new ArrayList<>( ids.length );
+					for (Object id : ids) {
+						final int pos = idList.indexOf(id);
+						list.add( pos < 0 ? null : resultList.get(pos) );
+					}
+					return list;
+				});
+	}
+
 	@Override
 	public <T> CompletionStage<T> reactiveGet(String entityName, Object id) {
 		return reactiveGet( entityName, id, LockMode.NONE, null );
 	}
 
 	@Override
-	public <T> CompletionStage<T> reactiveGet(Class<? extends T> entityClass, Object id, LockMode lockMode, EntityGraph<T> fetchGraph) {
+	public <T> CompletionStage<T> reactiveGet(Class<T> entityClass, Object id, LockMode lockMode, EntityGraph<T> fetchGraph) {
 		return reactiveGet( entityClass.getName(), id, LockMode.NONE, fetchGraph );
 	}
 

hibernate-reactive-core/src/main/java/org/hibernate/reactive/stage/Stage.java

@@ -1604,6 +1604,18 @@ interface StatelessSession extends Closeable {
 		 */
 		<T> CompletionStage<T> get(Class<T> entityClass, Object id);
 
+		/**
+		 * Retrieve multiple rows.
+		 *
+		 * @param entityClass The class of the entity to retrieve
+		 * @param ids The ids of the entities to retrieve
+		 *
+		 * @return a list of detached entity instances, via a {@code Uni}
+		 *
+		 * @see org.hibernate.StatelessSession#getMultiple(Class, List)
+		 */
+		<T> CompletionStage<List<T>> get(Class<T> entityClass, Object... ids);
+
 		/**
 		 * Retrieve a row, obtaining the specified lock mode.
 		 *

hibernate-reactive-core/src/main/java/org/hibernate/reactive/stage/impl/StageStatelessSessionImpl.java

@@ -50,6 +50,11 @@ public <T> CompletionStage<T> get(Class<T> entityClass, Object id) {
 		return delegate.reactiveGet( entityClass, id );
 	}
 
+	@Override
+	public <T> CompletionStage<List<T>> get(Class<T> entityClass, Object... ids) {
+		return delegate.reactiveGet( entityClass, ids );
+	}
+
 	@Override
 	public <T> CompletionStage<T> get(Class<T> entityClass, Object id, LockMode lockMode) {
 		return delegate.reactiveGet( entityClass, id, lockMode, null );