HHH-17151 Resolve explicit temporal bind type for null values

Author: mbladel

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

@@ -41,18 +41,40 @@ public <T> BindableType<T> resolveTemporalPrecision(
 			BindableType<T> declaredParameterType,
 			SessionFactoryImplementor sessionFactory) {
 		if ( precision != null ) {
-			final SqmExpressible<T> sqmExpressible = declaredParameterType.resolveExpressible( sessionFactory );
-			if ( !( JavaTypeHelper.isTemporal( sqmExpressible.getExpressibleJavaType() ) ) ) {
-				throw new UnsupportedOperationException(
-						"Cannot treat non-temporal parameter type with temporal precision"
-				);
+			final TemporalJavaType<T> temporalJtd;
+			if ( declaredParameterType != null ) {
+				final SqmExpressible<T> sqmExpressible = declaredParameterType.resolveExpressible( sessionFactory );
+				if ( !( JavaTypeHelper.isTemporal( sqmExpressible.getExpressibleJavaType() ) ) ) {
+					throw new UnsupportedOperationException(
+							"Cannot treat non-temporal parameter type with temporal precision"
+					);
+				}
+				temporalJtd = (TemporalJavaType<T>) sqmExpressible.getExpressibleJavaType();
+			}
+			else {
+				temporalJtd = null;
 			}
 
-			final TemporalJavaType<T> temporalJtd = (TemporalJavaType<T>) sqmExpressible.getExpressibleJavaType();
-			if ( temporalJtd.getPrecision() != precision ) {
+			if ( temporalJtd == null || temporalJtd.getPrecision() != precision ) {
 				final TypeConfiguration typeConfiguration = sessionFactory.getTypeConfiguration();
+				final TemporalJavaType<T> temporalTypeForPrecision;
+				// Special case java.util.Date, because TemporalJavaType#resolveTypeForPrecision doesn't support widening,
+				// since the main purpose of that method is to determine the final java type based on the reflective type
+				// + the explicit @Temporal(TemporalType...) configuration
+				if ( temporalJtd == null || java.util.Date.class.isAssignableFrom( temporalJtd.getJavaTypeClass() ) ) {
+					//noinspection unchecked
+					temporalTypeForPrecision = (TemporalJavaType<T>) typeConfiguration.getJavaTypeRegistry().getDescriptor(
+							TemporalJavaType.resolveJavaTypeClass( precision )
+					);
+				}
+				else {
+					temporalTypeForPrecision = temporalJtd.resolveTypeForPrecision(
+							precision,
+							typeConfiguration
+					);
+				}
 				return typeConfiguration.getBasicTypeRegistry().resolve(
-						temporalJtd.resolveTypeForPrecision( precision, typeConfiguration ),
+						temporalTypeForPrecision,
 						TemporalJavaType.resolveJdbcTypeCode( precision )
 				);
 			}

hibernate-core/src/main/java/org/hibernate/type/descriptor/java/TemporalJavaType.java

@@ -33,6 +33,18 @@ static int resolveJdbcTypeCode(TemporalType requestedTemporalPrecision) {
 		throw new UnsupportedOperationException( "Unsupported precision: " + requestedTemporalPrecision );
 	}
 
+	static Class<?> resolveJavaTypeClass(TemporalType requestedTemporalPrecision) {
+		switch ( requestedTemporalPrecision ) {
+			case DATE:
+				return java.sql.Date.class;
+			case TIME:
+				return java.sql.Time.class;
+			case TIMESTAMP:
+				return java.sql.Timestamp.class;
+		}
+		throw new UnsupportedOperationException( "Unsupported precision: " + requestedTemporalPrecision );
+	}
+
 	/**
 	 * The precision represented by this type
 	 */