Improved span passing for NettyClient.

without this change the child span has a wrong parent span id

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/ServletUtils.java

@@ -20,7 +20,7 @@ import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
 
 /**
- * Utility class to retrieve data from Servlet HTTP request and handle.
+ * Utility class to retrieve data from Servlet HTTP request and response.
  *
  * @author Marcin Grzejszczak
  * @since 1.0.0

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/SleuthHttpServerParser.java

@@ -72,7 +72,7 @@ class SleuthHttpServerParser extends HttpServerParser {
 			return;
 		}
 		if (httpStatus == HttpServletResponse.SC_OK && error != null) {
-			// Filter chain threw exception but the handle status may not have been set
+			// Filter chain threw exception but the response status may not have been set
 			// yet, so we have to guess.
 			customizer.tag(STATUS_CODE_KEY,
 					String.valueOf(HttpServletResponse.SC_INTERNAL_SERVER_ERROR));

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/client/TraceWebClientAutoConfiguration.java

@@ -19,6 +19,7 @@ package org.springframework.cloud.sleuth.instrument.web.client;
 import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 
@@ -349,8 +350,8 @@ class HttpClientBeanPostProcessor implements BeanPostProcessor {
 		@Override
 		public Mono<? extends Connection> apply(Mono<? extends Connection> mono,
 				Bootstrap bootstrap) {
-			return mono.subscriberContext(
-					context -> context.put(Span.class, tracer().nextSpan()));
+			return mono.subscriberContext(context -> context.put(AtomicReference.class,
+					new AtomicReference<>(tracer().currentSpan())));
 		}
 
 		private Tracer tracer() {
@@ -378,17 +379,6 @@ class HttpClientBeanPostProcessor implements BeanPostProcessor {
 				return "HttpHeaders::add";
 			}
 		};
-		static final Propagation.Getter<HttpHeaders, String> GETTER = new Propagation.Getter<HttpHeaders, String>() {
-			@Override
-			public String get(HttpHeaders carrier, String key) {
-				return carrier.get(key);
-			}
-
-			@Override
-			public String toString() {
-				return "HttpHeaders::get";
-			}
-		};
 
 		private static final Logger log = LoggerFactory
 				.getLogger(TracingDoOnRequest.class);
@@ -414,12 +404,11 @@ class HttpClientBeanPostProcessor implements BeanPostProcessor {
 
 		@Override
 		public void accept(HttpClientRequest req, Connection connection) {
-			Span span = req.currentContext().getOrDefault(Span.class,
-					this.tracer.nextSpan());
-			if (log.isDebugEnabled()) {
-				log.debug("Wrapping do on request");
-			}
-			this.handler.handleSend(this.injector, req.requestHeaders(), req, span);
+			AtomicReference reference = req.currentContext()
+					.getOrDefault(AtomicReference.class, new AtomicReference());
+			Span span = this.handler.handleSend(this.injector, req.requestHeaders(), req,
+					(Span) reference.get());
+			reference.set(span);
 		}
 
 	}
@@ -491,12 +480,13 @@ class HttpClientBeanPostProcessor implements BeanPostProcessor {
 
 		protected void handle(HttpClientResponse httpClientResponse,
 				Throwable throwable) {
-			Span span = httpClientResponse.currentContext().getOrDefault(Span.class,
-					null);
-			if (span == null) {
+			AtomicReference reference = httpClientResponse.currentContext()
+					.getOrDefault(AtomicReference.class, null);
+			if (reference == null || reference.get() == null) {
 				return;
 			}
-			this.handler.handleReceive(httpClientResponse, throwable, span);
+			this.handler.handleReceive(httpClientResponse, throwable,
+					(Span) reference.get());
 		}
 
 	}

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/web/client/TraceWebClientBeanPostProcessor.java

@@ -155,7 +155,7 @@ class TraceExchangeFilterFunction implements ExchangeFilterFunction {
 										|| clientResponse.statusCode() == null) {
 									if (log.isDebugEnabled()) {
 										log.debug(
-												"No handle was returned. Will close the span ["
+												"No response was returned. Will close the span ["
 														+ clientSpan + "]");
 									}
 									handleReceive(clientSpan, ws, clientResponse,
@@ -172,7 +172,7 @@ class TraceExchangeFilterFunction implements ExchangeFilterFunction {
 														+ clientSpan + "]");
 									}
 									throwable = new RestClientException(
-											"Status code of the handle is ["
+											"Status code of the response is ["
 													+ clientResponse.statusCode().value()
 													+ "] and the reason is ["
 													+ clientResponse.statusCode()

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/messaging/JmsTracingConfigurationTest.java

@@ -281,7 +281,7 @@ class JmsTestTracingConfiguration {
 	/**
 	 * When testing servers or asynchronous clients, spans are reported on a worker
 	 * thread. In order to read them on the main thread, we use a concurrent queue. As
-	 * some implementations report after a handle is sent, we use a blocking queue to
+	 * some implementations report after a response is sent, we use a blocking queue to
 	 * prevent race conditions in tests.
 	 */
 	BlockingQueue<Span> spans = new LinkedBlockingQueue<>();

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/web/TraceCustomFilterResponseInjectorTests.java

@@ -80,7 +80,7 @@ public class TraceCustomFilterResponseInjectorTests {
 				Map.class);
 
 		then(responseEntity.getHeaders()).containsKeys(TRACE_ID_NAME, SPAN_ID_NAME)
-				.as("Trace headers must be present in handle headers");
+				.as("Trace headers must be present in response headers");
 	}
 
 	@Configuration

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/web/client/integration/WebClientTests.java

@@ -293,11 +293,13 @@ public class WebClientTests {
 			then(response).isNotNull();
 		}
 
-		then(this.tracer.currentSpan()).isNull();
-		System.out.println("Collected span " + this.reporter.getSpans());
-		then(this.reporter.getSpans()).isNotEmpty().extracting("traceId", String.class)
-				.containsOnly(span.context().traceIdString());
-		then(this.reporter.getSpans()).extracting("kind.name").contains("CLIENT");
+		Awaitility.await().untilAsserted(() -> {
+			then(this.tracer.currentSpan()).isNull();
+			System.out.println("Collected span " + this.reporter.getSpans());
+			then(this.reporter.getSpans()).isNotEmpty().extracting("traceId", String.class)
+					.containsOnly(span.context().traceIdString());
+			then(this.reporter.getSpans()).extracting("kind.name").contains("CLIENT");
+		});
 	}
 
 	@Test

spring-cloud-sleuth-samples/spring-cloud-sleuth-sample-test-core/src/main/java/tools/RequestSendingRunnable.java

@@ -68,7 +68,7 @@ public class RequestSendingRunnable implements Runnable {
 		ResponseEntity<String> responseEntity = this.restTemplate
 				.exchange(requestWithTraceId(), String.class);
 		then(responseEntity.getStatusCode()).isEqualTo(HttpStatus.OK);
-		log.info(String.format("Received the following handle [%s]", responseEntity));
+		log.info(String.format("Received the following response [%s]", responseEntity));
 	}
 
 	private RequestEntity<Void> requestWithTraceId() {