本文整理了Java中brave.Tracer类的一些代码示例，展示了Tracer类的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Tracer类的具体详情如下：
包路径：brave.Tracer
类名称：Tracer

Tracer介绍

[英]Using a tracer, you can create a root span capturing the critical path of a request. Child spans can be created to allocate latency relating to outgoing requests. When tracing single-threaded code, just run it inside a scoped span:

// Start a new trace or a span within an existing trace representing an operationcatch (RuntimeException | Error e)  
span.error(e); // Unless you handle exceptions, you might not know the operation failed! 
throw e; 
} finally  
span.finish(); 
} 
}

When you need more features, or finer control, use the Span type:

// Start a new trace or a span within an existing trace representing an operationcatch (RuntimeException | Error e)  
span.error(e); // Unless you handle exceptions, you might not know the operation failed! 
throw e; 
} finally  
span.finish(); // note the scope is independent of the span. Always finish a span. 
} 
}

Both of the above examples report the exact same span on finish!
[中]使用跟踪器，您可以创建一个根范围来捕获请求的关键路径。可以创建子跨度来分配与传出请求相关的延迟。跟踪单线程代码时，只需在范围内运行它：

// Start a new trace or a span within an existing trace representing an operationcatch (RuntimeException | Error e)  
span.error(e); // Unless you handle exceptions, you might not know the operation failed! 
throw e; 
} finally  
span.finish(); 
} 
}

当需要更多功能或更精细的控制时，请使用跨度类型：

// Start a new trace or a span within an existing trace representing an operationcatch (RuntimeException | Error e)  
span.error(e); // Unless you handle exceptions, you might not know the operation failed! 
throw e; 
} finally  
span.finish(); // note the scope is independent of the span. Always finish a span. 
} 
}

以上两个例子报告的完工跨度完全相同！

代码示例

代码示例来源：origin: openzipkin/brave

/**
 * MethodInterceptor for {@link SimpleMessageListenerContainer.ContainerDelegate#invokeListener(Channel,
 * Message)}
 */
@Override public Object invoke(MethodInvocation methodInvocation) throws Throwable {
 Message message = (Message) methodInvocation.getArguments()[1];
 TraceContextOrSamplingFlags extracted = springRabbitTracing.extractAndClearHeaders(message);
 // named for BlockingQueueConsumer.nextMessage, which we can't currently see
 Span consumerSpan = tracer.nextSpan(extracted);
 Span listenerSpan = tracer.newChild(consumerSpan.context());
 if (!consumerSpan.isNoop()) {
  setConsumerSpan(consumerSpan, message.getMessageProperties());
  // incur timestamp overhead only once
  long timestamp = tracing.clock(consumerSpan.context()).currentTimeMicroseconds();
  consumerSpan.start(timestamp);
  long consumerFinish = timestamp + 1L; // save a clock reading
  consumerSpan.finish(consumerFinish);
  // not using scoped span as we want to start with a pre-configured time
  listenerSpan.name("on-message").start(consumerFinish);
 }
 try (SpanInScope ws = tracer.withSpanInScope(listenerSpan)) {
  return methodInvocation.proceed();
 } catch (Throwable t) {
  listenerSpan.error(t);
  throw t;
 } finally {
  listenerSpan.finish();
 }
}

代码示例来源：origin: spring-cloud/spring-cloud-sleuth

@RequestMapping("/traced")
public String traced() throws InterruptedException {
  Span span = this.tracer.nextSpan().name("http:customTraceEndpoint").start();
  int millis = this.random.nextInt(1000);
  log.info(String.format("Sleeping for [%d] millis", millis));
  Thread.sleep(millis);
  this.tracer.currentSpan().tag("random-sleep-millis", String.valueOf(millis));
  String s = this.restTemplate
      .getForObject("http://localhost:" + this.port + "/call", String.class);
  span.finish();
  return "traced/" + s;
}

代码示例来源：origin: openzipkin/brave

void joinWithSpanInScope(Tracer tracer, TraceContext context) {
 Span span = tracer.joinSpan(context).name("encode").start();
 try (Tracer.SpanInScope scope = tracer.withSpanInScope(span)) {
  span.tag("foo", "bar");
  span.tag("baz", "qux");
 } finally {
  span.finish();
 }
}

代码示例来源：origin: spring-cloud/spring-cloud-sleuth

private Span startOrContinueRenamedSpan(String spanName) {
  Span currentSpan = this.tracer.currentSpan();
  if (currentSpan != null) {
    return currentSpan.name(spanName);
  }
  return this.tracer.nextSpan().name(spanName);
}

代码示例来源：origin: openzipkin/brave

/**
 * Returns a new child span if there's a {@link #currentSpan()} or a new trace if there isn't.
 *
 * <p>Prefer {@link #startScopedSpan(String)} if you are tracing a synchronous function or code
 * block.
 */
public Span nextSpan() {
 TraceContext parent = currentTraceContext.get();
 return parent != null ? newChild(parent) : newTrace();
}

代码示例来源：origin: openzipkin/brave

void newChildWithSpanInScope(Tracer tracer, TraceContext context) {
 Span span = tracer.newChild(context).name("encode").start();
 try (Tracer.SpanInScope scope = tracer.withSpanInScope(span)) {
  span.tag("foo", "bar");
  span.tag("baz", "qux");
 } finally {
  span.finish();
 }
}

代码示例来源：origin: openzipkin/brave

Span startMessageListenerSpan(Message message) {
  if (!addConsumerSpan) return jmsTracing.nextSpan(message).name("on-message").start();
  TraceContextOrSamplingFlags extracted = jmsTracing.extractAndClearMessage(message);

  // JMS has no visibility of the incoming message, which incidentally could be local!
  Span consumerSpan = tracer.nextSpan(extracted).kind(CONSUMER).name("receive");
  Span listenerSpan = tracer.newChild(consumerSpan.context());

  if (!consumerSpan.isNoop()) {
   long timestamp = tracing.clock(consumerSpan.context()).currentTimeMicroseconds();
   consumerSpan.start(timestamp);
   if (remoteServiceName != null) consumerSpan.remoteServiceName(remoteServiceName);
   jmsTracing.tagQueueOrTopic(message, consumerSpan);
   long consumerFinish = timestamp + 1L; // save a clock reading
   consumerSpan.finish(consumerFinish);

   // not using scoped span as we want to start late
   listenerSpan.name("on-message").start(consumerFinish);
  }
  return listenerSpan;
 }
}

代码示例来源：origin: openzipkin/brave

final Span span;
if (kind.equals(Kind.CLIENT)) {
 span = tracer.nextSpan();
 injector.inject(span.context(), invocation.getAttachments());
} else {
 TraceContextOrSamplingFlags extracted = extractor.extract(invocation.getAttachments());
 span = extracted.context() != null
   ? tracer.joinSpan(extracted.context())
   : tracer.nextSpan(extracted);
if (!span.isNoop()) {
 span.kind(kind);
 String service = invoker.getInterface().getSimpleName();
 String method = RpcUtils.getMethodName(invocation);
try (Tracer.SpanInScope scope = tracer.withSpanInScope(span)) {
 Result result = invoker.invoke(invocation);
 if (result.hasException()) {

代码示例来源：origin: openzipkin/brave

span = tracer.nextSpan(kafkaTracing.extractAndClearHeaders(record.headers()));
} else {
 span = tracer.newChild(maybeParent);
if (!span.isNoop()) {
 span.kind(Span.Kind.PRODUCER).name("send");
 if (remoteServiceName != null) span.remoteServiceName(remoteServiceName);
 if (record.key() instanceof String && !"".equals(record.key())) {
injector.inject(span.context(), record.headers());
try (Tracer.SpanInScope ws = tracer.withSpanInScope(span)) {
 return delegate.send(record, TracingCallback.create(callback, span, current));
} catch (RuntimeException | Error e) {

代码示例来源：origin: apache/servicecomb-java-chassis

private Span createSpan(String spanName, String path) {
 Span currentSpan = tracer.currentSpan();
 if (currentSpan != null) {
  return tracer.newChild(currentSpan.context()).name(spanName).tag(CALL_PATH, path).start();
 }
 return tracer.newTrace().name(spanName).tag(CALL_PATH, path).start();
}

代码示例来源：origin: apache/cxf

@WebMethod
public Collection< Book > getBooks() {
  final Span span = brave.tracer().nextSpan().name("Get Books").start();
  try (SpanInScope scope = brave.tracer().withSpanInScope(span)) {
    return Arrays.asList(
        new Book("Apache CXF in Action", UUID.randomUUID().toString()),
        new Book("Mastering Apache CXF", UUID.randomUUID().toString())
      );
  } finally {
    span.finish();
  }
}

代码示例来源：origin: spring-cloud/spring-cloud-sleuth

TraceContextOrSamplingFlags extracted = this.extractor.extract(headers);
Span consumerSpan = this.tracer.nextSpan(extracted);
if (!consumerSpan.isNoop()) {
  consumerSpan.kind(Span.Kind.CONSUMER).start();
  consumerSpan.remoteServiceName(REMOTE_SERVICE_NAME);
  addTags(message, consumerSpan, channel);
    this.tracing.propagation().keys());
if (log.isDebugEnabled()) {
  log.debug("Created a new span in before handle" + consumerSpan);

代码示例来源：origin: openzipkin/brave

@Override public void send(Message message) throws JMSException {
 Span span = createAndStartProducerSpan(null, message);
 SpanInScope ws = tracer.withSpanInScope(span); // animal-sniffer mistakes this for AutoCloseable
 try {
  delegate.send(message);
 } catch (RuntimeException | JMSException | Error e) {
  span.error(e);
  throw e;
 } finally {
  ws.close();
  span.finish();
 }
}

代码示例来源：origin: openzipkin/brave

void nextWithSpanInScope(Tracer tracer, TraceContextOrSamplingFlags extracted) {
 Span span = tracer.nextSpan(extracted).name("encode").start();
 try (Tracer.SpanInScope scope = tracer.withSpanInScope(span)) {
  span.tag("foo", "bar");
  span.tag("baz", "qux");
 } finally {
  span.finish();
 }
}

代码示例来源：origin: apache/cxf

@Test
public void testThatProvidedSpanIsNotDetachedWhenActiveUsingAsyncClient() throws Exception {
  final WebClient client = createWebClient("/bookstore/books", braveClientProvider);
  final Span span = brave.tracer().nextSpan().name("test span").start();
  try {
    try (SpanInScope scope = brave.tracer().withSpanInScope(span)) {
      final Future<Response> f = client.async().get();
      final Response r = f.get(1, TimeUnit.SECONDS);
      assertEquals(Status.OK.getStatusCode(), r.getStatus());
      assertThat(brave.tracer().currentSpan().context().spanId(), equalTo(span.context().spanId()));
      assertThat(TestSpanReporter.getAllSpans().size(), equalTo(3));
      assertThat(TestSpanReporter.getAllSpans().get(0).name(), equalTo("get books"));
      assertThat(TestSpanReporter.getAllSpans().get(1).name(), equalTo("get /bookstore/books"));
      assertThat(TestSpanReporter.getAllSpans().get(2).name(), equalTo("get " + client.getCurrentURI()));
      assertThatTraceHeadersArePresent(r, true);
    }
  } finally {
    span.finish();
  }
  // Await till flush happens, usually a second is enough
  await().atMost(Duration.ONE_SECOND).until(()-> TestSpanReporter.getAllSpans().size() == 4);
  assertThat(TestSpanReporter.getAllSpans().size(), equalTo(4));
  assertThat(TestSpanReporter.getAllSpans().get(3).name(), equalTo("test span"));
}

代码示例来源：origin: openzipkin/brave

@Override
public <ReqT, RespT> ServerCall.Listener<ReqT> interceptCall(final ServerCall<ReqT, RespT> call,
  final Metadata headers, final ServerCallHandler<ReqT, RespT> next) {
 TraceContextOrSamplingFlags extracted = extractor.extract(headers);
 Span span = extracted.context() != null
   ? tracer.joinSpan(extracted.context())
   : tracer.nextSpan(extracted);
 // If grpc propagation is enabled, make sure we refresh the server method
 if (grpcPropagationFormatEnabled) {
  Tags tags = span.context().findExtra(Tags.class);
  if (tags != null) tags.put(RPC_METHOD, call.getMethodDescriptor().getFullMethodName());
 }
 span.kind(Span.Kind.SERVER);
 parser.onStart(call, headers, span.customizer());
 // startCall invokes user interceptors, so we place the span in scope here
 ServerCall.Listener<ReqT> result;
 SpanInScope scope = tracer.withSpanInScope(span);
 try { // retrolambda can't resolve this try/finally
  result = next.startCall(new TracingServerCall<>(span, call, parser), headers);
 } catch (RuntimeException | Error e) {
  span.error(e);
  span.finish();
  throw e;
 } finally {
  scope.close();
 }
 // This ensures the server implementation can see the span in scope
 return new ScopingServerCallListener<>(tracer, span, result, parser);
}

代码示例来源：origin: jaegertracing/spark-dependencies

@Override
public void createChildSpan(TracingWrapper<ZipkinWrapper> parent) {
 operationName = UUID.randomUUID().toString().replace("-","");
 if (parent == null) {
  // root node we start a new trace
  span = tracing.tracer().newTrace().name(operationName + "-root")
    .start();
 } else {
  brave.Span parentClient = parent.get().tracing.tracer().newChild(parent.get().span.context())
    .kind(Kind.CLIENT)
    .name(operationName + "-client")
    .start();
  // TODO if I finish this later the span is cached
  // and joined with server span and reported as a single span.
  // to properly solve this we have to look into the tags.
  // However there is another problem jaeger adds only one span.kind
  // (even if span contains cs,cr,sr,ss)
  // And it filters out core annotations, so there is no way how to find out
  // that there is a dependency link in this span.
  // https://github.com/jaegertracing/jaeger/issues/451
  parentClient.finish();
  span = tracing.tracer().joinSpan(parentClient.context())
    .name(operationName + "-server")
    .kind(Kind.SERVER)
    .start();
 }
}

代码示例来源：origin: openzipkin/brave

if (records.isEmpty() || tracing.isNoop()) return records;
long timestamp = 0L;
Map<String, Span> consumerSpansForTopic = new LinkedHashMap<>();
   Span span = consumerSpansForTopic.get(topic);
   if (span == null) {
    span = tracing.tracer().nextSpan(extracted);
    if (!span.isNoop()) {
     setConsumerSpan(topic, span);
      timestamp = tracing.clock(span.context()).currentTimeMicroseconds();
     span.start(timestamp);
   injector.inject(span.context(), record.headers());
  } else { // we extracted request-scoped data, so cannot share a consumer span.
   Span span = tracing.tracer().nextSpan(extracted);
   if (!span.isNoop()) {
    setConsumerSpan(topic, span);

代码示例来源：origin: spring-cloud/spring-cloud-sleuth

SpanSubscriber(Subscriber<? super T> subscriber, Context ctx, Tracing tracing,
    String name) {
  this.subscriber = subscriber;
  this.tracer = tracing.tracer();
  Span root = ctx.getOrDefault(Span.class, this.tracer.currentSpan());
  if (log.isTraceEnabled()) {
    log.trace("Span from context [{}]", root);
  }
  this.rootSpan = root;
  if (log.isTraceEnabled()) {
    log.trace("Stored context root span [{}]", this.rootSpan);
  }
  this.span = root != null ? this.tracer
      .nextSpan(TraceContextOrSamplingFlags.create(root.context())).name(name)
      : this.tracer.nextSpan().name(name);
  if (log.isTraceEnabled()) {
    log.trace("Created span [{}], with name [{}]", this.span, name);
  }
  this.context = ctx.put(Span.class, this.span);
}

代码示例来源：origin: xjdr/xio

@Override
 public void channelRead0(ChannelHandlerContext ctx, Request request) throws Exception {
  ByteBuf content =
    Unpooled.copiedBuffer("Here is the default content that is returned", CharsetUtil.UTF_8);
  HttpResponseStatus status = OK;
  Tracer tracer = httpTracing.tracing().tracer();
  if (request.endOfMessage()) {
   request
     .httpTraceInfo()
     .getSpan()
     .ifPresent(
       parent -> {
        if (parent instanceof brave.Span) {
         Span span =
           tracer.newChild(((brave.Span) parent).context()).name("child").start();
         span.finish();
        }
       });
   val response =
     DefaultFullResponse.builder()
       .status(status)
       .headers(new DefaultHeaders())
       .httpTraceInfo(request.httpTraceInfo())
       .status(status)
       .body(content)
       .build();
   ctx.writeAndFlush(response).addListener(ChannelFutureListener.CLOSE);
  }
 }
}