Add message keys to TraceKeys

User can now configure message headers to be added using
spring.sleuth.keys.message.headers.

Fixes gh-119

Also a bunch of cosmetic changes (imports etc).

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

@@ -16,13 +16,13 @@
 
 package org.springframework.cloud.sleuth.instrument;
 
-import lombok.EqualsAndHashCode;
-import lombok.Value;
+import java.util.concurrent.Callable;
+
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 
-import java.util.concurrent.Callable;
+import lombok.EqualsAndHashCode;
+import lombok.Value;
 
 /**
  * @author Spencer Gibb

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

@@ -54,6 +54,39 @@ public class TraceKeys {
 
 	private Http http = new Http();
 
+	private Message message = new Message();
+
+	@Data
+	public static class Message {
+
+		private Payload payload = new Payload();
+
+		@Data
+		public static class Payload {
+			/**
+			 * An estimate of the size of the payload if available.
+			 */
+			private String size = "message/payload-size";
+			/**
+			 * The type of the payload.
+			 */
+			private String type = "message/payload-type";
+		}
+
+		/**
+		 * Prefix for header names if they are added as tags.
+		 */
+		private String prefix = "message/";
+
+		/**
+		 * Additional headers that should be added as tags if they exist. If the header
+		 * value is not a String it will be converted to a String using its toString()
+		 * method.
+		 */
+		private Collection<String> headers = new LinkedHashSet<String>();
+
+	}
+
 	@Data
 	public static class Http {
 

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

@@ -21,7 +21,6 @@ import org.springframework.cloud.sleuth.Tracer;
 
 import lombok.EqualsAndHashCode;
 import lombok.Value;
-import org.springframework.cloud.sleuth.Tracer;
 
 /**
  * @author Spencer Gibb

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/async/AsyncDefaultAutoConfiguration.java

@@ -25,7 +25,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.scheduling.annotation.AsyncConfigurer;

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/executor/TraceableExecutorService.java

@@ -24,7 +24,6 @@ import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.instrument.TraceCallable;
 import org.springframework.cloud.sleuth.instrument.TraceRunnable;

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/executor/TraceableScheduledExecutorService.java

@@ -21,7 +21,6 @@ import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.instrument.TraceCallable;
 import org.springframework.cloud.sleuth.instrument.TraceRunnable;

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/AbstractTraceChannelInterceptor.java

@@ -1,17 +1,18 @@
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import java.util.Random;
+
 import org.springframework.cloud.sleuth.MilliSpan;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
 import org.springframework.integration.channel.AbstractMessageChannel;
 import org.springframework.integration.context.IntegrationObjectSupport;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.support.ChannelInterceptorAdapter;
 
-import java.util.Random;
-
 /**
  * Abstraction over classes related to channel intercepting
  *
@@ -19,15 +20,26 @@ import java.util.Random;
  */
 abstract class AbstractTraceChannelInterceptor extends ChannelInterceptorAdapter {
 
-	protected final Tracer tracer;
+	private final Tracer tracer;
 
-	protected final Random random;
+	private final Random random;
 
-	protected AbstractTraceChannelInterceptor(Tracer tracer, Random random) {
+	private final TraceKeys traceKeys;
+
+	protected AbstractTraceChannelInterceptor(Tracer tracer, TraceKeys traceKeys, Random random) {
 		this.tracer = tracer;
+		this.traceKeys = traceKeys;
 		this.random = random;
 	}
 
+	protected Tracer getTracer() {
+		return this.tracer;
+	}
+
+	protected TraceKeys getTraceKeys() {
+		return this.traceKeys;
+	}
+
 	/**
 	 * Returns a span given the message and a channel. Returns null when there was no
 	 * trace id passed initially.
@@ -37,7 +49,7 @@ abstract class AbstractTraceChannelInterceptor extends ChannelInterceptorAdapter
 			return null; // cannot build a span without ids
 		}
 		long spanId = hasHeader(message, Trace.SPAN_ID_NAME) ?
-				getHeader(message, Trace.SPAN_ID_NAME, Long.class) : random.nextLong();
+				getHeader(message, Trace.SPAN_ID_NAME, Long.class) : this.random.nextLong();
 		long traceId = getHeader(message, Trace.TRACE_ID_NAME, Long.class);
 		MilliSpan.MilliSpanBuilder span = MilliSpan.builder().traceId(traceId).spanId(spanId);
 		Long parentId = getHeader(message, Trace.PARENT_ID_NAME, Long.class);

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/SpanMessageHeaders.java

@@ -16,16 +16,17 @@
 
 package org.springframework.cloud.sleuth.instrument.integration;
 
-import org.springframework.cloud.sleuth.Span;
-import org.springframework.cloud.sleuth.Trace;
-import org.springframework.integration.support.MessageBuilder;
-import org.springframework.messaging.Message;
-import org.springframework.util.StringUtils;
-
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 
+import org.springframework.cloud.sleuth.Span;
+import org.springframework.cloud.sleuth.Trace;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
+import org.springframework.integration.support.MessageBuilder;
+import org.springframework.messaging.Message;
+import org.springframework.util.StringUtils;
+
 /**
  * Utility for manipulating message headers related to span data.
  *
@@ -34,7 +35,8 @@ import java.util.Map;
  */
 public class SpanMessageHeaders {
 
-	public static Message<?> addSpanHeaders(Message<?> message, Span span) {
+	public static Message<?> addSpanHeaders(TraceKeys traceKeys, Message<?> message,
+			Span span) {
 		if (span == null) {
 			if (!message.getHeaders().containsKey(Trace.NOT_SAMPLED_NAME)) {
 				return MessageBuilder.fromMessage(message)
@@ -48,40 +50,42 @@ public class SpanMessageHeaders {
 		addHeader(headers, Trace.SPAN_ID_NAME, span.getSpanId());
 
 		if (span.isExportable()) {
-			addAnnotations(message, span);
+			addAnnotations(traceKeys, message, span);
 			addHeader(headers, Trace.PARENT_ID_NAME, getFirst(span.getParents()));
 			addHeader(headers, Trace.SPAN_NAME_NAME, span.getName());
 			addHeader(headers, Trace.PROCESS_ID_NAME, span.getProcessId());
-		} else {
+		}
+		else {
 			addHeader(headers, Trace.NOT_SAMPLED_NAME, "");
 		}
 		return MessageBuilder.fromMessage(message).copyHeaders(headers).build();
 	}
 
-	public static void addAnnotations(Message<?> message, Span span) {
-		for (Map.Entry<String, Object> entry : message.getHeaders().entrySet()) {
-			if (!Trace.HEADERS.contains(entry.getKey())) { // filter out trace headers
-				String key = "/messaging/headers/" + entry.getKey().toLowerCase();
-				String value = null;
-				if (entry.getValue() != null) {
-					value = entry.getValue().toString(); // TODO: better way to serialize?
+	public static void addAnnotations(TraceKeys traceKeys, Message<?> message,
+			Span span) {
+		for (String name : traceKeys.getMessage().getHeaders()) {
+			if (message.getHeaders().containsKey(name)) {
+				String key = traceKeys.getMessage().getPrefix() + name.toLowerCase();
+				Object value = message.getHeaders().get(name);
+				if (value == null) {
+					value = "null";
 				}
-				span.tag(key, value);
+				span.tag(key, value.toString());  // TODO: better way to serialize?
 			}
 		}
-		addPayloadAnnotations(message.getPayload(), span);
+		addPayloadAnnotations(traceKeys, message.getPayload(), span);
 	}
 
-	static void addPayloadAnnotations(Object payload, Span span) {
+	static void addPayloadAnnotations(TraceKeys traceKeys, Object payload, Span span) {
 		if (payload != null) {
-			span.tag("/messaging/payload/type",
+			span.tag(traceKeys.getMessage().getPayload().getType(),
 					payload.getClass().getCanonicalName());
 			if (payload instanceof String) {
-				span.tag("/messaging/payload/size",
+				span.tag(traceKeys.getMessage().getPayload().getSize(),
 						String.valueOf(((String) payload).length()));
 			}
 			else if (payload instanceof byte[]) {
-				span.tag("/messaging/payload/size",
+				span.tag(traceKeys.getMessage().getPayload().getSize(),
 						String.valueOf(((byte[]) payload).length));
 			}
 		}
@@ -94,8 +98,7 @@ public class SpanMessageHeaders {
 		}
 	}
 
-	private static void addHeader(Map<String, String> headers, String name,
-			Long value) {
+	private static void addHeader(Map<String, String> headers, String name, Long value) {
 		if (value != null) {
 			addHeader(headers, name, Span.IdConverter.toHex(value));
 		}

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/StompMessageBuilder.java

@@ -16,6 +16,10 @@
 
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import java.util.List;
+import java.util.Map;
+import java.util.TreeMap;
+
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.trace.TraceContextHolder;
@@ -24,18 +28,14 @@ import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
 import org.springframework.messaging.simp.SimpMessageType;
 import org.springframework.util.StringUtils;
 
-import java.util.List;
-import java.util.Map;
-import java.util.TreeMap;
-
 /**
  * Builder class to create STOMP message
- * 
+ *
  * @author Gaurav Rai Mazra
  *
  */
 public class StompMessageBuilder {
-	
+
 	public static StompMessageBuilder fromMessage(Message<?> message) {
 		return new StompMessageBuilder(message);
 	}
@@ -89,7 +89,7 @@ public class StompMessageBuilder {
 				headerAccessor.getMessageHeaders());
 	}
 
-	private void pushHeaders(final SimpMessageHeaderAccessor assessor, final String key, final Object value) {
+	private void pushHeaders(final SimpMessageHeaderAccessor accessor, final String key, final Object value) {
 		switch (key) {
 		case SimpMessageHeaderAccessor.DESTINATION_HEADER:
 		case SimpMessageHeaderAccessor.MESSAGE_TYPE_HEADER:
@@ -107,10 +107,10 @@ public class StompMessageBuilder {
 		case Trace.SPAN_ID_NAME:
 		case Trace.SPAN_NAME_NAME:
 		case Trace.TRACE_ID_NAME:
-			assessor.setHeader(key, value);
+			accessor.setHeader(key, value);
 			break;
 		default:
-			assessor.setNativeHeader(key, value == null ? null : value.toString());
+			accessor.setNativeHeader(key, value == null ? null : value.toString());
 		}
 	}
 

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/TraceChannelInterceptor.java

@@ -16,15 +16,16 @@
 
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import java.util.Random;
+
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
 import org.springframework.cloud.sleuth.sampler.IsTracingSampler;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
 
-import java.util.Random;
-
 /**
  * @author Dave Syer
  *
@@ -33,38 +34,38 @@ public class TraceChannelInterceptor extends AbstractTraceChannelInterceptor {
 
 	private ThreadLocal<Trace> traceHolder = new ThreadLocal<>();
 
-	public TraceChannelInterceptor(Tracer tracer, Random random) {
-		super(tracer, random);
+	public TraceChannelInterceptor(Tracer tracer, TraceKeys traceKeys, Random random) {
+		super(tracer, traceKeys, random);
 	}
 
 	@Override
 	public void postSend(Message<?> message, MessageChannel channel, boolean sent) {
 		Trace trace = this.traceHolder.get();
 		// Double close to clean up the parent (remote span as well)
-		this.tracer.close(this.tracer.close(trace));
+		getTracer().close(getTracer().close(trace));
 		this.traceHolder.remove();
 	}
 
 	@Override
 	public Message<?> preSend(Message<?> message, MessageChannel channel) {
-		if (this.tracer.isTracing()) {
-			return SpanMessageHeaders.addSpanHeaders(message,
-					this.tracer.getCurrentSpan());
+		if (getTracer().isTracing()) {
+			return SpanMessageHeaders.addSpanHeaders(getTraceKeys(), message,
+					getTracer().getCurrentSpan());
 		}
 		String name = getMessageChannelName(channel);
 		Trace trace = startSpan(buildSpan(message), name, message);
 		this.traceHolder.set(trace);
-		return SpanMessageHeaders.addSpanHeaders(message, trace.getSpan());
+		return SpanMessageHeaders.addSpanHeaders(getTraceKeys(), message, trace.getSpan());
 	}
 
-	private Trace startSpan(Span span, String name, Message message) {
+	private Trace startSpan(Span span, String name, Message<?> message) {
 		if (span != null) {
-			return tracer.joinTrace(name, span);
+			return getTracer().joinTrace(name, span);
 		}
 		if (message.getHeaders().containsKey(Trace.NOT_SAMPLED_NAME)) {
-			return tracer.startTrace(name, IsTracingSampler.INSTANCE);
+			return getTracer().startTrace(name, IsTracingSampler.INSTANCE);
 		}
-		return this.tracer.startTrace(name);
+		return getTracer().startTrace(name);
 	}
 
 }

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/TraceSpringIntegrationAutoConfiguration.java

@@ -16,19 +16,20 @@
 
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import java.util.Random;
+
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
-import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.autoconfig.TraceAutoConfiguration;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.integration.config.GlobalChannelInterceptor;
 
-import java.util.Random;
-
 /**
  * @author Spencer Gibb
  */
@@ -37,6 +38,7 @@ import java.util.Random;
 @ConditionalOnBean(Tracer.class)
 @AutoConfigureAfter(TraceAutoConfiguration.class)
 @ConditionalOnProperty(value = "spring.sleuth.integration.enabled", matchIfMissing = true)
+@EnableConfigurationProperties(TraceKeys.class)
 public class TraceSpringIntegrationAutoConfiguration {
 
 	@Bean
@@ -48,19 +50,21 @@ public class TraceSpringIntegrationAutoConfiguration {
 
 	@Bean
 	@GlobalChannelInterceptor
-	public TraceChannelInterceptor traceChannelInterceptor(Tracer tracer, Random random) {
-		return new TraceChannelInterceptor(tracer, random);
+	public TraceChannelInterceptor traceChannelInterceptor(Tracer tracer,
+			TraceKeys traceKeys, Random random) {
+		return new TraceChannelInterceptor(tracer, traceKeys, random);
 	}
 
 	@Bean
-	public TraceStompMessageChannelInterceptor traceStompMessageChannelInterceptor(Tracer tracer, Random random) {
-		return new TraceStompMessageChannelInterceptor(tracer, random);
+	public TraceStompMessageChannelInterceptor traceStompMessageChannelInterceptor(
+			Tracer tracer, TraceKeys traceKeys, Random random) {
+		return new TraceStompMessageChannelInterceptor(tracer, traceKeys, random);
 	}
 
 	@Bean
 	public TraceStompMessageContextPropagationChannelInterceptor traceStompMessageContextPropagationChannelInteceptor(
-			Tracer tracer) {
-		return new TraceStompMessageContextPropagationChannelInterceptor(tracer);
+			Tracer tracer, TraceKeys traceKeys) {
+		return new TraceStompMessageContextPropagationChannelInterceptor(tracer, traceKeys);
 	}
 
 }

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/TraceStompMessageChannelInterceptor.java

@@ -15,33 +15,34 @@
  */
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import java.util.Random;
+
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
 import org.springframework.messaging.support.ChannelInterceptor;
 
-import java.util.Random;
-
 /**
  * Interceptor for Stomp Messages sent over websocket
- * 
+ *
  * @author Gaurav Rai Mazra
  * @author Marcin Grzejszczak
- * 
+ *
  */
 public class TraceStompMessageChannelInterceptor extends AbstractTraceChannelInterceptor implements ChannelInterceptor {
 	private ThreadLocal<Trace> traceScopeHolder = new ThreadLocal<Trace>();
 
-	public TraceStompMessageChannelInterceptor(Tracer tracer, Random random) {
-		super(tracer, random);
+	public TraceStompMessageChannelInterceptor(Tracer tracer, TraceKeys traceKeys, Random random) {
+		super(tracer, traceKeys, random);
 	}
 
 	@Override
 	public Message<?> preSend(Message<?> message, MessageChannel channel) {
-		if (tracer.isTracing() || message.getHeaders().containsKey(Trace.NOT_SAMPLED_NAME)) {
-			return StompMessageBuilder.fromMessage(message).setHeadersFromSpan(tracer.getCurrentSpan()).build();
+		if (getTracer().isTracing() || message.getHeaders().containsKey(Trace.NOT_SAMPLED_NAME)) {
+			return StompMessageBuilder.fromMessage(message).setHeadersFromSpan(getTracer().getCurrentSpan()).build();
 		}
 		String name = getMessageChannelName(channel);
 		Trace trace = startSpan(buildSpan(message), name);
@@ -51,16 +52,16 @@ public class TraceStompMessageChannelInterceptor extends AbstractTraceChannelInt
 
 	private Trace startSpan(Span span, String name) {
 		if (span != null) {
-			return tracer.joinTrace(name, span);
+			return getTracer().joinTrace(name, span);
 		}
-		return tracer.startTrace(name);
+		return getTracer().startTrace(name);
 	}
 
 	@Override
 	public void postSend(Message<?> message, MessageChannel channel, boolean sent) {
 		final ThreadLocal<Trace> traceScopeHolder = this.traceScopeHolder;
 		Trace traceInScope = traceScopeHolder.get();
-		this.tracer.close(traceInScope);
+		getTracer().close(traceInScope);
 		traceScopeHolder.remove();
 	}
 }

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/integration/TraceStompMessageContextPropagationChannelInterceptor.java

@@ -16,13 +16,11 @@
 
 package org.springframework.cloud.sleuth.instrument.integration;
 
-import java.util.Map;
-
 import org.springframework.aop.support.AopUtils;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
+import org.springframework.cloud.sleuth.instrument.TraceKeys;
 import org.springframework.integration.channel.DirectChannel;
 import org.springframework.messaging.Message;
 import org.springframework.messaging.MessageChannel;
@@ -43,9 +41,11 @@ public class TraceStompMessageContextPropagationChannelInterceptor extends Chann
 
 	private final Tracer tracer;
 	private final static ThreadLocal<Trace> ORIGINAL_CONTEXT = new ThreadLocal<>();
+	private TraceKeys traceKeys;
 
-	public TraceStompMessageContextPropagationChannelInterceptor(Tracer tracer) {
+	public TraceStompMessageContextPropagationChannelInterceptor(Tracer tracer, TraceKeys traceKeys) {
 		this.tracer = tracer;
+		this.traceKeys = traceKeys;
 	}
 
 	@Override
@@ -55,12 +55,23 @@ public class TraceStompMessageContextPropagationChannelInterceptor extends Chann
 		}
 		Span span = this.tracer.getCurrentSpan();
 		if (span != null) {
-			return new MessageWithSpan(message, span);
+			return createMessageWithSpan(message, span);
 		} else {
 			return message;
 		}
 	}
 
+	private Message<?> createMessageWithSpan(Message<?> message, Span span) {
+		MessageWithSpan output = new MessageWithSpan(message, span);
+		addAnnotationsToSpanFromMessage(output, span);
+		return output;
+	}
+
+	private void addAnnotationsToSpanFromMessage(Message<?> message, Span span) {
+		SpanMessageHeaders.addAnnotations(this.traceKeys, message, span);
+		SpanMessageHeaders.addPayloadAnnotations(this.traceKeys, message.getPayload(), span);
+	}
+
 	@Override
 	public final Message<?> postReceive(Message<?> message, MessageChannel channel) {
 		if (message instanceof MessageWithSpan) {
@@ -103,18 +114,6 @@ public class TraceStompMessageContextPropagationChannelInterceptor extends Chann
 			Assert.notNull(span, "span can not be null");
 			this.span = span;
 			this.message = StompMessageBuilder.fromMessage(message).setHeadersFromSpan(this.span).build();
-			addAnnotationsToSpanFromMessage(this.message, this.span);
-		}
-
-		private void addAnnotationsToSpanFromMessage(Message<?> message, Span span) {
-			for (Map.Entry<String, Object> entry : message.getHeaders().entrySet()) {
-				if (!Trace.HEADERS.contains(entry.getKey())) {
-					String key = "/messaging/headers/" + entry.getKey().toLowerCase();
-					String value = entry.getValue() == null ? null : entry.getValue().toString();
-					span.tag(key, value);
-				}
-			}
-			SpanMessageHeaders.addPayloadAnnotations(message.getPayload(), span);
 		}
 
 		@Override

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/instrument/scheduling/TraceSchedulingAutoConfiguration.java

@@ -26,7 +26,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.autoconfig.TraceAutoConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;

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

@@ -25,7 +25,6 @@ import org.aspectj.lang.annotation.Aspect;
 import org.aspectj.lang.annotation.Pointcut;
 import org.springframework.cloud.sleuth.TraceAccessor;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.instrument.TraceCallable;
 import org.springframework.stereotype.Controller;
 import org.springframework.web.bind.annotation.RestController;

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

@@ -21,7 +21,6 @@ import java.lang.reflect.InvocationHandler;
 import java.lang.reflect.Method;
 import java.util.Map;
 
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.instrument.hystrix.TraceCommand;
 
@@ -38,11 +37,11 @@ import feign.Target;
  */
 final class SleuthHystrixInvocationHandler implements InvocationHandler {
 
-  private final Target target;
+  private final Target<?> target;
   private final Map<Method, MethodHandler> dispatch;
   private final Tracer tracer;
 
-  SleuthHystrixInvocationHandler(Target target, Map<Method, MethodHandler> dispatch, Tracer tracer) {
+  SleuthHystrixInvocationHandler(Target<?> target, Map<Method, MethodHandler> dispatch, Tracer tracer) {
     this.tracer = checkNotNull(tracer, "traceManager");
     this.target = checkNotNull(target, "target");
     this.dispatch = checkNotNull(dispatch, "dispatch");
@@ -56,7 +55,7 @@ final class SleuthHystrixInvocationHandler implements InvocationHandler {
         .withGroupKey(HystrixCommandGroupKey.Factory.asKey(groupKey))
         .andCommandKey(HystrixCommandKey.Factory.asKey(commandKey));
 
-    HystrixCommand<Object> hystrixCommand = new TraceCommand<Object>(tracer, setter) {
+    HystrixCommand<Object> hystrixCommand = new TraceCommand<Object>(this.tracer, setter) {
       @Override
       public Object doRun() throws Exception {
         try {
@@ -84,8 +83,8 @@ final class SleuthHystrixInvocationHandler implements InvocationHandler {
     }
 
     @Override
-    public InvocationHandler create(Target target, Map<Method, MethodHandler> dispatch) {
-      return new SleuthHystrixInvocationHandler(target, dispatch, tracer);
+    public InvocationHandler create(@SuppressWarnings("rawtypes") Target target, Map<Method, MethodHandler> dispatch) {
+      return new SleuthHystrixInvocationHandler(target, dispatch, this.tracer);
     }
   }
 }

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

@@ -16,10 +16,14 @@
 
 package org.springframework.cloud.sleuth.instrument.web.client;
 
-import com.netflix.hystrix.HystrixCommand;
-import feign.*;
-import feign.codec.Decoder;
-import feign.hystrix.HystrixFeign;
+import static java.util.Collections.singletonList;
+
+import java.io.IOException;
+import java.lang.reflect.Type;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.beans.factory.ObjectFactory;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.AutoConfigureAfter;
@@ -35,7 +39,6 @@ import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.TraceAccessor;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.event.ClientReceivedEvent;
 import org.springframework.cloud.sleuth.event.ClientSentEvent;
 import org.springframework.cloud.sleuth.instrument.hystrix.SleuthHystrixAutoConfiguration;
@@ -48,13 +51,16 @@ import org.springframework.context.annotation.Primary;
 import org.springframework.context.annotation.Scope;
 import org.springframework.util.StringUtils;
 
-import java.io.IOException;
-import java.lang.reflect.Type;
-import java.util.Collection;
-import java.util.HashMap;
-import java.util.Map;
+import com.netflix.hystrix.HystrixCommand;
 
-import static java.util.Collections.singletonList;
+import feign.Client;
+import feign.Feign;
+import feign.FeignException;
+import feign.RequestInterceptor;
+import feign.RequestTemplate;
+import feign.Response;
+import feign.codec.Decoder;
+import feign.hystrix.HystrixFeign;
 
 /**
  *

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/log/SleuthLogAutoConfiguration.java

@@ -23,7 +23,6 @@ import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.autoconfig.TraceAutoConfiguration;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/sampler/PercentageBasedSampler.java

@@ -1,6 +1,5 @@
 package org.springframework.cloud.sleuth.sampler;
 
-import lombok.extern.slf4j.Slf4j;
 import org.springframework.cloud.sleuth.Sampler;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.TraceAccessor;
@@ -21,7 +20,6 @@ import org.springframework.cloud.sleuth.TraceAccessor;
  * @author Marcin Grzejszczak
  * @author Adrian Cole
  */
-@Slf4j
 public class PercentageBasedSampler implements Sampler<Void> {
 
 	private final SamplerConfiguration configuration;
@@ -34,8 +32,8 @@ public class PercentageBasedSampler implements Sampler<Void> {
 
 	@Override
 	public boolean next() {
-		Span currentSpan = traceAccessor.getCurrentSpan();
-		long threshold = Math.abs(Long.MAX_VALUE * (int) (configuration.getPercentage() * 100)); // drops fractional percentage.
+		Span currentSpan = this.traceAccessor.getCurrentSpan();
+		long threshold = Math.abs(Long.MAX_VALUE * (int) (this.configuration.getPercentage() * 100)); // drops fractional percentage.
 		if (currentSpan == null || threshold == 0L) {
 			return false;
 		}

spring-cloud-sleuth-core/src/main/java/org/springframework/cloud/sleuth/template/TraceTemplate.java

@@ -18,7 +18,6 @@ package org.springframework.cloud.sleuth.template;
 
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.instrument.TraceDelegate;
 
 /**

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

@@ -1,5 +1,11 @@
 package org.springframework.cloud.sleuth.instrument;
 
+import static org.assertj.core.api.BDDAssertions.then;
+
+import java.util.Random;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -7,19 +13,11 @@ import org.mockito.Mockito;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.sampler.AlwaysSampler;
 import org.springframework.cloud.sleuth.trace.DefaultTracer;
-import org.springframework.cloud.sleuth.trace.DefaultTracer;
 import org.springframework.cloud.sleuth.trace.TraceContextHolder;
 import org.springframework.context.ApplicationEventPublisher;
 
-import java.util.Random;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-
-import static org.assertj.core.api.BDDAssertions.then;
-
 @RunWith(MockitoJUnitRunner.class)
 public class TraceRunnableTests {
 

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/executor/TraceableExecutorServiceTests.java

@@ -1,6 +1,17 @@
 package org.springframework.cloud.sleuth.instrument.executor;
 
-import lombok.SneakyThrows;
+import static java.util.stream.Collectors.toList;
+import static org.assertj.core.api.BDDAssertions.then;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Queue;
+import java.util.Random;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.ConcurrentLinkedQueue;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -15,17 +26,7 @@ import org.springframework.cloud.sleuth.trace.DefaultTracer;
 import org.springframework.cloud.sleuth.trace.TraceContextHolder;
 import org.springframework.context.ApplicationEventPublisher;
 
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Queue;
-import java.util.Random;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.ConcurrentLinkedQueue;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
-
-import static java.util.stream.Collectors.toList;
-import static org.assertj.core.api.BDDAssertions.then;
+import lombok.SneakyThrows;
 
 @RunWith(MockitoJUnitRunner.class)
 public class TraceableExecutorServiceTests {
@@ -39,34 +40,34 @@ public class TraceableExecutorServiceTests {
 
 	@Before
 	public void setup() {
-		tracer = new DefaultTracer(new AlwaysSampler(), new Random(), publisher);
-		traceManagerableExecutorService = new TraceableExecutorService(executorService, tracer);
+		this.tracer = new DefaultTracer(new AlwaysSampler(), new Random(), this.publisher);
+		this.traceManagerableExecutorService = new TraceableExecutorService(this.executorService, this.tracer);
 		TraceContextHolder.removeCurrentTrace();
 	}
 
 	@After
 	public void tearDown() throws Exception {
-		tracer = null;
-		traceManagerableExecutorService.shutdown();
-		executorService.shutdown();
+		this.tracer = null;
+		this.traceManagerableExecutorService.shutdown();
+		this.executorService.shutdown();
 		TraceContextHolder.removeCurrentTrace();
 	}
 
 	@Test
 	@SneakyThrows
 	public void should_propagate_trace_id_and_set_new_span_when_traceable_executor_service_is_executed() {
-		Trace trace = tracer.startTrace("PARENT");
+		Trace trace = this.tracer.startTrace("PARENT");
 		CompletableFuture.allOf(runnablesExecutedViaTraceManagerableExecutorService()).get();
-		tracer.close(trace);
+		this.tracer.close(trace);
 
-		then(spanVerifyingRunnable.traceIds.stream().distinct().collect(toList())).containsOnly(trace.getSpan().getTraceId());
-		then(spanVerifyingRunnable.spanIds.stream().distinct().collect(toList())).hasSize(TOTAL_THREADS);
+		then(this.spanVerifyingRunnable.traceIds.stream().distinct().collect(toList())).containsOnly(trace.getSpan().getTraceId());
+		then(this.spanVerifyingRunnable.spanIds.stream().distinct().collect(toList())).hasSize(TOTAL_THREADS);
 	}
 
-	private CompletableFuture[] runnablesExecutedViaTraceManagerableExecutorService() {
-		List<CompletableFuture> futures = new ArrayList<>();
+	private CompletableFuture<?>[] runnablesExecutedViaTraceManagerableExecutorService() {
+		List<CompletableFuture<?>> futures = new ArrayList<>();
 		for (int i = 0; i < TOTAL_THREADS; i++) {
-			futures.add(CompletableFuture.runAsync(spanVerifyingRunnable, traceManagerableExecutorService));
+			futures.add(CompletableFuture.runAsync(this.spanVerifyingRunnable, this.traceManagerableExecutorService));
 		}
 		return futures.toArray(new CompletableFuture[futures.size()]);
 	}
@@ -79,8 +80,8 @@ public class TraceableExecutorServiceTests {
 		@Override
 		public void run() {
 			Span span = TraceContextHolder.getCurrentSpan();
-			traceIds.add(span.getTraceId());
-			spanIds.add(span.getSpanId());
+			this.traceIds.add(span.getTraceId());
+			this.spanIds.add(span.getSpanId());
 		}
 
 	}

spring-cloud-sleuth-core/src/test/java/org/springframework/cloud/sleuth/instrument/integration/AbstractTraceStompIntegrationTests.java

@@ -1,5 +1,7 @@
 package org.springframework.cloud.sleuth.instrument.integration;
 
+import static org.assertj.core.api.BDDAssertions.then;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.runner.RunWith;
@@ -14,10 +16,8 @@ import org.springframework.messaging.support.ExecutorSubscribableChannel;
 import org.springframework.messaging.support.GenericMessage;
 import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 
-import static org.assertj.core.api.BDDAssertions.then;
-
 @RunWith(SpringJUnit4ClassRunner.class)
-abstract class AbstractTraceStompIntegrationTests {
+public abstract class AbstractTraceStompIntegrationTests {
 
 	@Autowired
 	@Qualifier("executorSubscribableChannel")
@@ -29,17 +29,17 @@ abstract class AbstractTraceStompIntegrationTests {
 
 	@Before
 	public void init() {
-		this.channel.subscribe(stompMessageHandler);
+		this.channel.subscribe(this.stompMessageHandler);
 	}
 
 	@After
 	public void close() {
 		TraceContextHolder.removeCurrentTrace();
-		this.channel.unsubscribe(stompMessageHandler);
+		this.channel.unsubscribe(this.stompMessageHandler);
 	}
 
 	Trace givenALocallyStartedSpan() {
-		return tracer.startTrace("testSendMessage", sampler);
+		return this.tracer.startTrace("testSendMessage", this.sampler);
 	}
 
 	Message<?> givenMessageToBeSampled() {
@@ -48,7 +48,7 @@ abstract class AbstractTraceStompIntegrationTests {
 
 	void whenTheMessageWasSent(Message<?> message) {
 		this.channel.send(message);
-		then(stompMessageHandler.message).isNotNull();
+		then(this.stompMessageHandler.message).isNotNull();
 	}
 
 	Long thenSpanIdFromHeadersIsNotEmpty() {
@@ -64,6 +64,6 @@ abstract class AbstractTraceStompIntegrationTests {
 	}
 
 	<T> T getValueFromHeaders(String headerName, Class<T> type) {
-		return stompMessageHandler.message.getHeaders().get(headerName, type);
+		return this.stompMessageHandler.message.getHeaders().get(headerName, type);
 	}
 }

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

@@ -1,8 +1,12 @@
 package org.springframework.cloud.sleuth.instrument.web.client;
 
-import com.netflix.loadbalancer.BaseLoadBalancer;
-import com.netflix.loadbalancer.ILoadBalancer;
-import com.netflix.loadbalancer.Server;
+import static org.assertj.core.api.BDDAssertions.then;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.Random;
+
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -18,7 +22,6 @@ import org.springframework.cloud.sleuth.MilliSpan;
 import org.springframework.cloud.sleuth.Span;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.Tracer;
-import org.springframework.cloud.sleuth.Tracer;
 import org.springframework.cloud.sleuth.event.ClientReceivedEvent;
 import org.springframework.cloud.sleuth.event.ClientSentEvent;
 import org.springframework.cloud.sleuth.trace.TraceContextHolder;
@@ -35,12 +38,9 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 import org.springframework.web.bind.annotation.RestController;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.Random;
-
-import static org.assertj.core.api.BDDAssertions.then;
+import com.netflix.loadbalancer.BaseLoadBalancer;
+import com.netflix.loadbalancer.ILoadBalancer;
+import com.netflix.loadbalancer.Server;
 
 @RunWith(SpringJUnit4ClassRunner.class)
 @SpringApplicationConfiguration(classes = { FeignTraceTests.TestConfiguration.class })

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

@@ -16,6 +16,14 @@
 
 package org.springframework.cloud.sleuth.instrument.web.client;
 
+import static org.assertj.core.api.BDDAssertions.then;
+import static org.junit.Assert.assertFalse;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Random;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -23,7 +31,6 @@ import org.springframework.cloud.sleuth.MilliSpan;
 import org.springframework.cloud.sleuth.Trace;
 import org.springframework.cloud.sleuth.sampler.AlwaysSampler;
 import org.springframework.cloud.sleuth.trace.DefaultTracer;
-import org.springframework.cloud.sleuth.trace.DefaultTracer;
 import org.springframework.cloud.sleuth.trace.TraceContextHolder;
 import org.springframework.context.support.StaticApplicationContext;
 import org.springframework.http.HttpHeaders;
@@ -36,14 +43,6 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestTemplate;
 
-import java.util.Arrays;
-import java.util.HashMap;
-import java.util.Map;
-import java.util.Random;
-
-import static org.assertj.core.api.BDDAssertions.then;
-import static org.junit.Assert.assertFalse;
-
 /**
  * @author Dave Syer
  *