优化

common-web/src/main/java/com/baiyue/common/web/FeignTracePropagationAutoConfiguration.java

@@ -0,0 +1,18 @@
+package com.baiyue.common.web;
+
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.context.annotation.Bean;
+
+/** Enables synchronous Feign trace propagation without making Feign a required dependency. */
+@AutoConfiguration(afterName = "org.springframework.cloud.openfeign.FeignAutoConfiguration")
+@ConditionalOnClass(name = "feign.RequestInterceptor")
+public class FeignTracePropagationAutoConfiguration {
+
+    @Bean
+    @ConditionalOnMissingBean(FeignTraceRequestInterceptor.class)
+    FeignTraceRequestInterceptor feignTraceRequestInterceptor() {
+        return new FeignTraceRequestInterceptor();
+    }
+}

common-web/src/main/java/com/baiyue/common/web/FeignTraceRequestInterceptor.java

@@ -0,0 +1,41 @@
+package com.baiyue.common.web;
+
+import feign.RequestInterceptor;
+import feign.RequestTemplate;
+import org.slf4j.MDC;
+import org.springframework.core.Ordered;
+
+import java.util.regex.Pattern;
+
+/** Propagates the trusted synchronous request trace context to every Feign invocation. */
+public final class FeignTraceRequestInterceptor implements RequestInterceptor, Ordered {
+    private static final Pattern SAFE_REQUEST_ID = Pattern.compile("[A-Za-z0-9._:-]{1,128}");
+
+    @Override
+    public void apply(RequestTemplate template) {
+        removeManagedHeaders(template);
+
+        String requestId = MDC.get(CorrelationContext.REQUEST_ID);
+        if (requestId != null && SAFE_REQUEST_ID.matcher(requestId).matches()) {
+            template.header(CorrelationContext.REQUEST_ID_HEADER, requestId);
+        }
+
+        String traceId = MDC.get(CorrelationContext.TRACE_ID);
+        if (TraceParent.validLegacyTraceId(traceId)) {
+            TraceParent outbound = TraceParent.outboundChild(traceId);
+            template.header(CorrelationContext.TRACE_ID_HEADER, outbound.traceId());
+            template.header(CorrelationContext.TRACE_PARENT_HEADER, outbound.value());
+        }
+    }
+
+    @Override
+    public int getOrder() {
+        return Ordered.LOWEST_PRECEDENCE;
+    }
+
+    private void removeManagedHeaders(RequestTemplate template) {
+        template.removeHeader(CorrelationContext.REQUEST_ID_HEADER);
+        template.removeHeader(CorrelationContext.TRACE_ID_HEADER);
+        template.removeHeader(CorrelationContext.TRACE_PARENT_HEADER);
+    }
+}

common-web/src/main/java/com/baiyue/common/web/TraceParent.java

@@ -55,6 +55,14 @@ public record TraceParent(String traceId, String parentId, String traceFlags) {
         return new TraceParent(traceId, randomNonZero(8), "00");
     }
 
+    /** Creates a sampled outbound child for a trusted current trace ID. */
+    public static TraceParent outboundChild(String currentTraceId) {
+        if (!validLegacyTraceId(currentTraceId)) {
+            throw new IllegalArgumentException("Current trace ID is invalid");
+        }
+        return new TraceParent(currentTraceId.toLowerCase(java.util.Locale.ROOT), randomNonZero(8), "01");
+    }
+
     public static boolean validLegacyTraceId(String value) {
         return value != null && LEGACY_TRACE_ID.matcher(value).matches()
                 && !ZERO_TRACE_ID.equalsIgnoreCase(value);