fix(ollama): null check on chat model response' duration metadata

 - Fixed an issue where the `from` method of `org.springframework.ai.ollama.OllamaChatModel` could not work correctly when a tool call occurred while using Ollama.

Signed-off-by: Sun Yuhan <[email protected]>

Author: sunyuhan1998

models/spring-ai-ollama/src/main/java/org/springframework/ai/ollama/OllamaChatModel.java

@@ -84,6 +84,7 @@
  * @author Jihoon Kim
  * @author Alexandros Pappas
  * @author Ilayaperumal Gopinathan
+ * @author Sun Yuhan
  * @since 1.0.0
  */
 public class OllamaChatModel implements ChatModel {
@@ -170,18 +171,21 @@ static ChatResponseMetadata from(OllamaApi.ChatResponse response, ChatResponse p
 		Duration totalDuration = response.getTotalDuration();
 
 		if (previousChatResponse != null && previousChatResponse.getMetadata() != null) {
-			if (previousChatResponse.getMetadata().get(METADATA_EVAL_DURATION) != null) {
-				evalDuration = evalDuration.plus(previousChatResponse.getMetadata().get(METADATA_EVAL_DURATION));
+			Object metadataEvalDuration = previousChatResponse.getMetadata().get(METADATA_EVAL_DURATION);
+			if (metadataEvalDuration != null && evalDuration != null) {
+				evalDuration = evalDuration.plus((Duration) metadataEvalDuration);
 			}
-			if (previousChatResponse.getMetadata().get(METADATA_PROMPT_EVAL_DURATION) != null) {
-				promptEvalDuration = promptEvalDuration
-					.plus(previousChatResponse.getMetadata().get(METADATA_PROMPT_EVAL_DURATION));
+			Object metadataPromptEvalDuration = previousChatResponse.getMetadata().get(METADATA_PROMPT_EVAL_DURATION);
+			if (metadataPromptEvalDuration != null && promptEvalDuration != null) {
+				promptEvalDuration = promptEvalDuration.plus((Duration) metadataPromptEvalDuration);
 			}
-			if (previousChatResponse.getMetadata().get(METADATA_LOAD_DURATION) != null) {
-				loadDuration = loadDuration.plus(previousChatResponse.getMetadata().get(METADATA_LOAD_DURATION));
+			Object metadataLoadDuration = previousChatResponse.getMetadata().get(METADATA_LOAD_DURATION);
+			if (metadataLoadDuration != null && loadDuration != null) {
+				loadDuration = loadDuration.plus((Duration) metadataLoadDuration);
 			}
-			if (previousChatResponse.getMetadata().get(METADATA_TOTAL_DURATION) != null) {
-				totalDuration = totalDuration.plus(previousChatResponse.getMetadata().get(METADATA_TOTAL_DURATION));
+			Object metadataTotalDuration = previousChatResponse.getMetadata().get(METADATA_TOTAL_DURATION);
+			if (metadataTotalDuration != null && totalDuration != null) {
+				totalDuration = totalDuration.plus((Duration) metadataTotalDuration);
 			}
 			if (previousChatResponse.getMetadata().getUsage() != null) {
 				promptTokens += previousChatResponse.getMetadata().getUsage().getPromptTokens();

models/spring-ai-ollama/src/test/java/org/springframework/ai/ollama/OllamaChatModelTests.java

@@ -37,8 +37,7 @@
 import org.springframework.ai.ollama.management.ModelManagementOptions;
 
 import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.junit.jupiter.api.Assertions.*;
 
 /**
  * @author Jihoon Kim
@@ -146,4 +145,28 @@ void buildChatResponseMetadataAggregationWithNonEmptyMetadata() {
 		assertEquals(promptEvalCount + 66, (Integer) metadata.get("prompt-eval-count"));
 	}
 
+	@Test
+	void buildChatResponseMetadataAggregationWithNonEmptyMetadataButEmptyEval() {
+
+		OllamaApi.ChatResponse response = new OllamaApi.ChatResponse("model", Instant.now(), null, null, null, null,
+				null, null, null, null, null);
+
+		ChatResponse previousChatResponse = ChatResponse.builder()
+			.generations(List.of())
+			.metadata(ChatResponseMetadata.builder()
+				.usage(new DefaultUsage(66, 99))
+				.keyValue("eval-duration", Duration.ofSeconds(2))
+				.keyValue("prompt-eval-duration", Duration.ofSeconds(2))
+				.build())
+			.build();
+
+		ChatResponseMetadata metadata = OllamaChatModel.from(response, previousChatResponse);
+
+		assertNull(metadata.get("eval-duration"));
+		assertNull(metadata.get("prompt-eval-duration"));
+		assertEquals(Integer.valueOf(99), metadata.get("eval-count"));
+		assertEquals(Integer.valueOf(66), metadata.get("prompt-eval-count"));
+
+	}
+
 }