fix(qdrant): support Long type in payload by converting to String

Qdrant does not support java.lang.Long as a native payload type.
Previously, passing a Long value caused the following exception:

  java.lang.IllegalArgumentException: Unsupported Qdrant value type: class java.lang.Long
    at org.springframework.ai.vectorstore.qdrant.QdrantValueFactory.value(QdrantValueFactory.java:85)
    at org.springframework.ai.vectorstore.qdrant.QdrantValueFactory.lambda$toValueMap$1(QdrantValueFactory.java:46)
    ...

To resolve this, Long values are now converted to their String representation
in QdrantValueFactory. This preserves precision and avoids serialization issues.

test(qdrant): add test to verify Long metadata values are stored as String

Adds a test to ensure that Long values in document metadata are
safely converted to String before being stored in Qdrant.

The test inserts a document with a Long-type "ref_id", performs
a similarity search, and verifies that:
- the result is not empty,
- the retrieved "ref_id" is a String,
- the value matches the original Long when parsed.

Also ensures cleanup by deleting the inserted document from the store.

Signed-off-by: Solomon Hsu <solnone@gmail.com>
(cherry picked from commit f0d4cbf037)

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

@@ -75,6 +75,9 @@ final class QdrantValueFactory {
 				return ValueFactory.value((String) value);
 			case "Integer":
 				return ValueFactory.value((Integer) value);
+			case "Long":
+				// use String representation
+				return ValueFactory.value(String.valueOf(value));
 			case "Double":
 				return ValueFactory.value((Double) value);
 			case "Float":

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

@@ -314,6 +314,27 @@ public class QdrantVectorStoreIT extends BaseVectorStoreTests {
 		});
 	}
 
+	@Test
+	void shouldConvertLongToString() {
+		this.contextRunner.run(context -> {
+			QdrantVectorStore vectorStore = context.getBean(QdrantVectorStore.class);
+			var refId = System.currentTimeMillis();
+			var doc = new Document("Long type ref_id", Map.of("ref_id", refId));
+			vectorStore.add(List.of(doc));
+
+			List<Document> results = vectorStore
+				.similaritySearch(SearchRequest.builder().query("Long type ref_id").topK(1).build());
+			assertThat(results).hasSize(1);
+			Document resultDoc = results.get(0);
+			var resultRefId = resultDoc.getMetadata().get("ref_id");
+			assertThat(resultRefId).isInstanceOf(String.class);
+			assertThat(Double.valueOf((String) resultRefId)).isEqualTo(refId);
+
+			// Remove all documents from the store
+			vectorStore.delete(List.of(resultDoc.getId()));
+		});
+	}
+
 	@SpringBootConfiguration
 	public static class TestApplication {