Nullpointer when using Azure Open AI and streaming

[berjanjonker]

Bug description
While using the AzureOpenAI chat client streaming won't work. It gets into this nullpointer. When I subscribe and print out the .content() Flux; I noticed that the last received token is null.

2025-04-10 17:38:22.611 [http-nio-8080-exec-7] ERROR o.a.c.c.C.[.[.[.[dispatcherServlet].log - Servlet.service() for servlet [dispatcherServlet] threw exception
java.lang.NullPointerException: Cannot invoke "com.azure.ai.openai.models.ChatResponseMessage.getToolCalls()" because "responseMessage" is null
at org.springframework.ai.azure.openai.AzureOpenAiChatModel.buildGeneration(AzureOpenAiChatModel.java:498)
Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException:
Assembly trace from producer [reactor.core.publisher.FluxMapFuseable] :
reactor.core.publisher.Flux.map(Flux.java:6588)
org.springframework.ai.azure.openai.AzureOpenAiChatModel.lambda$internalStream$13(AzureOpenAiChatModel.java:381)

Environment
Spring-AI 1.0.0-M6
Chat Model: Azure OpenAI

Steps to reproduce
chatClient.prompt().user("How are you?").stream().content().doOnEach(data -> System.out.println(data.get()));

//output
How
can
I
assist
you
today
?
null

Expected behavior
AzureOpenAiChatModel should be null safe or null values should be filtered out.

Minimal Complete Reproducible example
See above. When I switch to another vendor like Anthrophic the result is as expected (without a null at the end of the stream)

[dev-jonghoonpark]

I got the same result with the OpenAI module.

[dev-jonghoonpark]

I have found that this issue is not related to Spring AI.

doOnEach handles multiple events.
In the provided code, it calls the onComplete event as the final step after all tasks are completed.
Since there is no data in the onComplete event, it results in null.

Using doOnNext instead of doOnEach will resolve the issue.

[ReloadingPeace]

I have found that this issue is not related to Spring AI.

doOnEach handles multiple events. In the provided code, it calls the onComplete event as the final step after all tasks are completed. Since there is no data in the onComplete event, it results in null.

Using doOnNext instead of doOnEach will resolve the issue.

I am a beginner, please forgive me if there are any mistakes in what I said. Here is my opinion:
I think the null pointer caused by the Azure OpenAiChatModel not processing ChatResponse properly cannot be avoided when obtaining results, whether it is doOnNext or doOnEach

[berjanjonker]

I have found that this issue is not related to Spring AI.
doOnEach handles multiple events. In the provided code, it calls the onComplete event as the final step after all tasks are completed. Since there is no data in the onComplete event, it results in null.
Using doOnNext instead of doOnEach will resolve the issue.

I am a beginner, please forgive me if there are any mistakes in what I said. Here is my opinion: I think the null pointer caused by the Azure OpenAiChatModel not processing ChatResponse properly cannot be avoided when obtaining results, whether it is doOnNext or doOnEach

I agree. Created a PR to make the processing of chatReponses more robust

[markpollack]

thanks so much! will review.