Refactor QdrantObjectFactory to allow null metadata values

Add test for check toObjectMap method allows null metadata values

Signed-off-by: WOONBE <kepull2918@naver.com>

vector-stores/spring-ai-qdrant-store/src/main/java/org/springframework/ai/vectorstore/qdrant/QdrantObjectFactory.java

@@ -16,6 +16,7 @@
 
 package org.springframework.ai.vectorstore.qdrant;
 
+import java.util.HashMap;
 import java.util.Map;
 import java.util.stream.Collectors;
 
@@ -30,6 +31,7 @@ import org.springframework.util.Assert;
  * Utility methods for building Java objects from io.qdrant.client.grpc.JsonWithInt.Value.
  *
  * @author Anush Shetty
+ * @author Heonwoo Kim
  * @since 0.8.1
  */
 final class QdrantObjectFactory {
@@ -41,7 +43,11 @@ final class QdrantObjectFactory {
 
 	public static Map<String, Object> toObjectMap(Map<String, Value> payload) {
 		Assert.notNull(payload, "Payload map must not be null");
-		return payload.entrySet().stream().collect(Collectors.toMap(e -> e.getKey(), e -> object(e.getValue())));
+		Map<String, Object> map = new HashMap<>();
+		for (Map.Entry<String, Value> entry : payload.entrySet()) {
+			map.put(entry.getKey(), object(entry.getValue()));
+		}
+		return map;
 	}
 
 	private static Object object(ListValue listValue) {

vector-stores/spring-ai-qdrant-store/src/test/java/org/springframework/ai/vectorstore/qdrant/QdrantObjectFactoryTests.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright 2023-2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.ai.vectorstore.qdrant;
+
+import java.util.Map;
+
+import io.qdrant.client.grpc.JsonWithInt.NullValue;
+import io.qdrant.client.grpc.JsonWithInt.Value;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for {@link QdrantObjectFactory}.
+ *
+ * @author Heonwoo Kim
+ */
+
+class QdrantObjectFactoryTests {
+
+	@Test
+	void toObjectMapShouldHandleNullValues() {
+		Map<String, Value> payloadWithNull = Map.of("name", Value.newBuilder().setStringValue("Spring AI").build(),
+				"version", Value.newBuilder().setDoubleValue(1.0).build(), "is_ga",
+				Value.newBuilder().setBoolValue(true).build(), "description",
+				Value.newBuilder().setNullValue(NullValue.NULL_VALUE).build());
+
+		Map<String, Object> result = QdrantObjectFactory.toObjectMap(payloadWithNull);
+
+		assertThat(result).isNotNull();
+		assertThat(result).hasSize(4);
+		assertThat(result.get("name")).isEqualTo("Spring AI");
+		assertThat(result.get("version")).isEqualTo(1.0);
+		assertThat(result.get("is_ga")).isEqualTo(true);
+		assertThat(result).containsKey("description");
+		assertThat(result.get("description")).isNull();
+	}
+
+}