Support NullHandling in QueryUtils.

Closes #3811

Signed-off-by: Alim <[email protected]>

Author: alim-n

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/QueryUtils.java

@@ -87,6 +87,7 @@
  * @author Pranav HS
  * @author Eduard Dudar
  * @author Yanming Zhou
+ * @author Alim Naizabek
  */
 public abstract class QueryUtils {
 
@@ -430,7 +431,13 @@ static Set<String> getFunctionAliases(String query) {
 	}
 
 	private static String toJpaDirection(Order order) {
-		return order.getDirection().name().toLowerCase(Locale.US);
+		String direction = order.getDirection().name().toLowerCase(Locale.US);
+		if (order.getNullHandling() == Sort.NullHandling.NULLS_FIRST) {
+			direction += " nulls first";
+		} else if (order.getNullHandling() == Sort.NullHandling.NULLS_LAST) {
+			direction += " nulls last";
+		}
+		return direction;
 	}
 
 	/**

spring-data-jpa/src/test/java/org/springframework/data/jpa/repository/query/DefaultQueryEnhancerUnitTests.java

@@ -48,4 +48,14 @@ void shouldApplySorting() {
 
 		assertThat(sql).isEqualTo("SELECT e FROM Employee e order by e.foo asc, e.bar asc");
 	}
+
+	@Test
+	void shouldApplySortingWithNullHandling() {
+
+		QueryEnhancer enhancer = createQueryEnhancer(DeclaredQuery.of("SELECT e FROM Employee e", true));
+
+		String sql = enhancer.applySorting(Sort.by(Sort.Order.asc("foo").nullsFirst(), Sort.Order.asc("bar").nullsLast()));
+
+		assertThat(sql).isEqualTo("SELECT e FROM Employee e order by e.foo asc nulls first, e.bar asc nulls last");
+	}
 }