HHH-11278 - setMaxResult(0) should return an empty List

hibernate-core/src/main/java/org/hibernate/internal/CriteriaImpl.java

@@ -252,6 +252,7 @@ public class CriteriaImpl implements Criteria, Serializable {
 	public Integer getMaxResults() {
 		return maxResults;
 	}
+
 	@Override
 	public Criteria setMaxResults(int maxResults) {
 		this.maxResults = maxResults;

hibernate-core/src/main/java/org/hibernate/internal/EmptyScrollableResults.java

@@ -0,0 +1,207 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later.
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.internal;
+
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.sql.Blob;
+import java.sql.Clob;
+import java.util.Calendar;
+import java.util.Date;
+import java.util.Locale;
+import java.util.TimeZone;
+
+import org.hibernate.query.spi.ScrollableResultsImplementor;
+import org.hibernate.type.Type;
+
+/**
+ * @author Andrea Boriero
+ */
+public class EmptyScrollableResults implements ScrollableResultsImplementor {
+
+	public static final ScrollableResultsImplementor INSTANCE = new EmptyScrollableResults();
+
+	@Override
+	public boolean isClosed() {
+		return true;
+	}
+
+	@Override
+	public int getNumberOfTypes() {
+		return 0;
+	}
+
+	@Override
+	public void close() {
+
+	}
+
+	@Override
+	public boolean next() {
+		return false;
+	}
+
+	@Override
+	public boolean previous() {
+		return false;
+	}
+
+	@Override
+	public boolean scroll(int positions) {
+		return false;
+	}
+
+	@Override
+	public boolean last() {
+		return true;
+	}
+
+	@Override
+	public boolean first() {
+		return false;
+	}
+
+	@Override
+	public void beforeFirst() {
+
+	}
+
+	@Override
+	public void afterLast() {
+
+	}
+
+	@Override
+	public boolean isFirst() {
+		return false;
+	}
+
+	@Override
+	public boolean isLast() {
+		return false;
+	}
+
+	@Override
+	public int getRowNumber() {
+		return 0;
+	}
+
+	@Override
+	public boolean setRowNumber(int rowNumber) {
+		return false;
+	}
+
+	@Override
+	public Object[] get() {
+		return new Object[0];
+	}
+
+	@Override
+	public Object get(int i) {
+		return null;
+	}
+
+	@Override
+	public Type getType(int i) {
+		return null;
+	}
+
+	@Override
+	public Integer getInteger(int col) {
+		return null;
+	}
+
+	@Override
+	public Long getLong(int col) {
+		return null;
+	}
+
+	@Override
+	public Float getFloat(int col) {
+		return null;
+	}
+
+	@Override
+	public Boolean getBoolean(int col) {
+		return null;
+	}
+
+	@Override
+	public Double getDouble(int col) {
+		return null;
+	}
+
+	@Override
+	public Short getShort(int col) {
+		return null;
+	}
+
+	@Override
+	public Byte getByte(int col) {
+		return null;
+	}
+
+	@Override
+	public Character getCharacter(int col) {
+		return null;
+	}
+
+	@Override
+	public byte[] getBinary(int col) {
+		return new byte[0];
+	}
+
+	@Override
+	public String getText(int col) {
+		return null;
+	}
+
+	@Override
+	public Blob getBlob(int col) {
+		return null;
+	}
+
+	@Override
+	public Clob getClob(int col) {
+		return null;
+	}
+
+	@Override
+	public String getString(int col) {
+		return null;
+	}
+
+	@Override
+	public BigDecimal getBigDecimal(int col) {
+		return null;
+	}
+
+	@Override
+	public BigInteger getBigInteger(int col) {
+		return null;
+	}
+
+	@Override
+	public Date getDate(int col) {
+		return null;
+	}
+
+	@Override
+	public Locale getLocale(int col) {
+		return null;
+	}
+
+	@Override
+	public Calendar getCalendar(int col) {
+		return null;
+	}
+
+	@Override
+	public TimeZone getTimeZone(int col) {
+		return null;
+	}
+}

hibernate-core/src/main/java/org/hibernate/internal/SessionImpl.java

@@ -1846,6 +1846,9 @@ public final class SessionImpl
 	public List list(Criteria criteria) throws HibernateException {
 		// TODO: Is this guaranteed to always be CriteriaImpl?
 		CriteriaImpl criteriaImpl = (CriteriaImpl) criteria;
+		if ( criteriaImpl.getMaxResults() != null && criteriaImpl.getMaxResults() == 0 ) {
+			return Collections.EMPTY_LIST;
+		}
 
 		final NaturalIdLoadAccess naturalIdLoadAccess = this.tryNaturalIdLoadAccess( criteriaImpl );
 		if ( naturalIdLoadAccess != null ) {

hibernate-core/src/main/java/org/hibernate/procedure/internal/ProcedureCallImpl.java

@@ -744,6 +744,9 @@ public class ProcedureCallImpl<R>
 	@Override
 	@SuppressWarnings("unchecked")
 	public List<R> getResultList() {
+		if ( getMaxResults() == 0 ) {
+			return Collections.EMPTY_LIST;
+		}
 		try {
 			final Output rtn = outputs().getCurrent();
 			if ( ! ResultSetOutput.class.isInstance( rtn ) ) {

hibernate-core/src/main/java/org/hibernate/query/internal/AbstractProducedQuery.java

@@ -55,9 +55,11 @@ import org.hibernate.engine.spi.RowSelection;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.engine.spi.TypedValue;
 import org.hibernate.hql.internal.QueryExecutionRequestException;
+import org.hibernate.internal.EmptyScrollableResults;
 import org.hibernate.internal.EntityManagerMessageLogger;
 import org.hibernate.internal.HEMLogging;
 import org.hibernate.internal.util.collections.ArrayHelper;
+import org.hibernate.internal.util.collections.EmptyIterator;
 import org.hibernate.jpa.QueryHints;
 import org.hibernate.jpa.TypedParameterValue;
 import org.hibernate.jpa.graph.internal.EntityGraphImpl;
@@ -815,7 +817,7 @@ public abstract class AbstractProducedQuery<R> implements QueryImplementor<R> {
 	@Override
 	@SuppressWarnings("unchecked")
 	public QueryImplementor setMaxResults(int maxResult) {
-		if ( maxResult <= 0 ) {
+		if ( maxResult < 0 ) {
 			// treat zero and negatives specially as meaning no limit...
 			queryOptions.setMaxRows( null );
 		}
@@ -1344,6 +1346,9 @@ public abstract class AbstractProducedQuery<R> implements QueryImplementor<R> {
 
 	@SuppressWarnings("unchecked")
 	protected Iterator<R> doIterate() {
+		if (getMaxResults() == 0){
+			return EmptyIterator.INSTANCE;
+		}
 		return getProducer().iterate(
 				queryParameterBindings.expandListValuedParameters( getQueryString(), getProducer() ),
 				getQueryParameters()
@@ -1367,6 +1372,9 @@ public abstract class AbstractProducedQuery<R> implements QueryImplementor<R> {
 	}
 
 	protected ScrollableResultsImplementor doScroll(ScrollMode scrollMode) {
+		if (getMaxResults() == 0){
+			return EmptyScrollableResults.INSTANCE;
+		}
 		final String query = queryParameterBindings.expandListValuedParameters( getQueryString(), getProducer() );
 		QueryParameters queryParameters = getQueryParameters();
 		queryParameters.setScrollMode( scrollMode );
@@ -1376,6 +1384,10 @@ public abstract class AbstractProducedQuery<R> implements QueryImplementor<R> {
 	@Override
 	@SuppressWarnings("unchecked")
 	public Stream<R> stream() {
+		if (getMaxResults() == 0){
+			final Spliterator<R> spliterator = Spliterators.emptySpliterator();
+			return StreamSupport.stream( spliterator, false );
+		}
 		final ScrollableResultsImplementor scrollableResults = scroll( ScrollMode.FORWARD_ONLY );
 		final ScrollableResultsIterator<R> iterator = new ScrollableResultsIterator<>( scrollableResults );
 		final Spliterator<R> spliterator = Spliterators.spliteratorUnknownSize( iterator, Spliterator.NONNULL );
@@ -1417,6 +1429,9 @@ public abstract class AbstractProducedQuery<R> implements QueryImplementor<R> {
 
 	@SuppressWarnings("unchecked")
 	protected List<R> doList() {
+		if ( getMaxResults() == 0 ) {
+			return Collections.EMPTY_LIST;
+		}
 		if ( lockOptions.getLockMode() != null && lockOptions.getLockMode() != LockMode.NONE ) {
 			if ( !getProducer().isTransactionInProgress() ) {
 				throw new TransactionRequiredException( "no transaction is in progress" );