Spring Boot 3.1下Micrometer Tracing无法传递至下游（无RestTemplate）求助

由于你使用OpenAPI Generator生成的客户端、未依赖RestTemplate，可通过自定义拦截器注入TraceId相关请求头，同时兼容Spring Boot 3.1的Micrometer Tracing与下游2.7.x的Sleuth格式，具体步骤如下：

1. 自定义OpenAPI请求拦截器 #

利用OpenAPI Generator客户端的RequestInterceptor扩展点，在请求发送前注入TraceId相关头信息：

import io.micrometer.tracing.Tracer;
import org.openapitools.client.api.ApiClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class OpenApiClientConfig {

    private final Tracer tracer;

    public OpenApiClientConfig(Tracer tracer) {
        this.tracer = tracer;
    }

    @Bean
    public ApiClient apiClient() {
        ApiClient apiClient = new ApiClient();
        // 添加自定义请求拦截器
        apiClient.addRequestInterceptor(request -> {
            var currentSpan = tracer.currentSpan();
            if (currentSpan != null) {
                var traceContext = currentSpan.context();
                // 注入Sleuth兼容的B3格式头信息
                request.header("X-B3-TraceId", traceContext.traceId());
                request.header("X-B3-SpanId", traceContext.spanId());
                request.header("X-B3-Sampled", "1");
            }
        });
        return apiClient;
    }
}

2. 确认Micrometer Tracing依赖配置 #

Spring Boot 3.1已用Micrometer Tracing替代Sleuth，需引入正确的桥接依赖：

<dependency>
    <groupId>io.micrometer</groupId>
    <artifactId>micrometer-tracing-bridge-brave</artifactId>
</dependency>
<dependency>
    <groupId>io.zipkin.reporter2</groupId>
    <artifactId>zipkin-reporter-brave</artifactId>
</dependency>

3. 配置Trace传播格式 #

下游2.7.x依赖Sleuth的B3格式，需在application.yml中指定传播类型：

management:
  tracing:
    propagation:
      type: B3

4. 验证生效 #

启动服务后，调用OpenAPI生成的客户端接口，检查请求头是否包含X-B3-TraceId、X-B3-SpanId字段，同时确认下游服务日志能正确接收并打印TraceId。

内容的提问来源于stack exchange，提问作者Rishy Rane