Spring AI WebClientResponseException$UnprocessableEntity: 422 Unprocessable Entity

Bug description When integrating the locally deployed model of our own, there was an error when accessing it in a streaming manner, but there was no problem when accessing it in a non-streaming manner.

org.springframework.web.reactive.function.client.WebClientResponseException$UnprocessableEntity: 422 Unprocessable Entity from POST http://152.136.158.152:9002/v1/chat/completions
    at org.springframework.web.reactive.function.client.WebClientResponseException.create(WebClientResponseException.java:331) ~[spring-webflux-6.2.7.jar:6.2.7]
    Suppressed: reactor.core.publisher.FluxOnAssembly$OnAssemblyException: 
Error has been observed at the following site(s):
    *__checkpoint ⇢ 422 UNPROCESSABLE_ENTITY from POST http://152.136.158.152:9002/v1/chat/completions [DefaultWebClient]

Swift deployed Qwen 2.5 - 0.5B

CUDA_VISIBLE_DEVICES=0 swift deploy \
    --model Qwen/Qwen2.5-0.5B-Instruct \
    --infer_backend vllm \
    --max_new_tokens 2048 \
    --served_model_name qwen

Environment springboot:3.4.5 springai:1.0.0

code pom

 <properties>
      <maven.compiler.source>17</maven.compiler.source>
      <maven.compiler.target>17</maven.compiler.target>
      <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>
  <dependencies>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-web</artifactId>
      </dependency>
      <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-test</artifactId>
          <scope>test</scope>
      </dependency>

      <dependency>
          <groupId>org.springframework.ai</groupId>
          <artifactId>spring-ai-starter-model-openai</artifactId>
      </dependency>
  </dependencies>
  <dependencyManagement>

      <dependencies>
          <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-dependencies</artifactId>
              <version>3.4.5</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
          <dependency>
              <groupId>org.springframework.ai</groupId>
              <artifactId>spring-ai-bom</artifactId>
              <version>1.0.0</version>
              <type>pom</type>
              <scope>import</scope>
          </dependency>
      </dependencies>
  </dependencyManagement>
  <repositories>
      <repository>
          <id>spring-snapshots</id>
          <name>Spring Snapshots</name>
          <url>https://repo.spring.io/snapshot</url>
          <releases>
              <enabled>false</enabled>
          </releases>
      </repository>
      <repository>
          <name>Central Portal Snapshots</name>
          <id>central-portal-snapshots</id>
          <url>https://central.sonatype.com/repository/maven-snapshots/</url>
          <releases>
              <enabled>false</enabled>
          </releases>
          <snapshots>
              <enabled>true</enabled>
          </snapshots>
      </repository>
  </repositories>
  <build>
      <plugins>
          <plugin>
              <groupId>org.apache.maven.plugins</groupId>
              <artifactId>maven-compiler-plugin</artifactId>
              <configuration>
                  <compilerArgs>
                      <arg>-parameters</arg>
                  </compilerArgs>
              </configuration>
          </plugin>
          <plugin>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-maven-plugin</artifactId>
          </plugin>
      </plugins>
  </build>

application.yaml

spring:
  ai:
    openai:
      api-key: 111
#      base-url: https://api.deepseek.com
      base-url: http://152.136.158.152:9002

      chat:
        options:
          model: qwen
#          model: deepseek-chat

  http:
    client:
      factory: simple

MainTest.java

@SpringBootTest
class MainTest {
    @Autowired
    ChatClient.Builder builder;

    // Error
    @Test
    public void testA() {
        Flux<String> content1 = builder.build().prompt(Prompt.builder().messages(List.of(new UserMessage("你是谁"))).build()).stream().content();
        System.out.println(content1.blockLast());
    }

    // success
    @Test
    public void testB() {
        String content = builder.build().prompt(Prompt.builder().messages(List.of(new UserMessage("你是谁"))).build()).call().content();
        System.out.println(content);
    }
}

Comment From: dev-jonghoonpark

Will it succeed if I send a POST request directly without using Spring AI?

Comment From: w22296437978

Will it succeed if I send a POST request directly without using Spring AI?

Comment From: dev-jonghoonpark

When testing locally, the following logs were output:

WARNING: Unsupported upgrade request. INFO: 127.0.0.1:50752 - "POST /v1/chat/completions HTTP/1.1" 422 Unprocessable Entity

The Java HttpClient attempts to upgrade to HTTP 2.0 by default, so you need to configure it manually to use HTTP 1.1.

Please refer to the comments on the issues below for the solution.

related issue - https://github.com/spring-projects/spring-ai/issues/3124 - https://github.com/spring-projects/spring-ai/issues/2653

Comment From: w22296437978

Thank you. It's solved.