Java OpenCensus：通过POST请求进行跟踪传播

在Java中，我试图通过HttpPost请求（org.apache.HTTP.client.methods.HttpPost）传播TraceContext。我将上下文参数传递给标题，如下所示：

    try (Scope scope = tracer.spanBuilder("firstSpan").startScopedSpan()) {

        SpanContext spanContext = tracer.getCurrentSpan().getContext();
        
        StringBuilder builder =
                new StringBuilder()
                    .append(spanContext.getTraceId().toLowerBase16())
                    .append(SPAN_ID_DELIMITER)
                    .append(UnsignedLongs.toString(spanIdToLong(spanContext.getSpanId())))
                    .append(TRACE_OPTION_DELIMITER)
                    .append(spanContext.getTraceOptions().isSampled() ? SAMPLED : NOT_SAMPLED);

        httpPost.addHeader(HEADER_NAME, builder.toString());

        HttpResponse response = reportSession.getHttpClient().execute(httpPost,reportSession.getHttpContext());

请求由Servlet（在单独的JAR中）处理，我在其中检索参数并尝试打开一个新的范围：

    String headerStr = req.getHeader(HEADER_NAME);

    TraceId traceId = TraceId.fromLowerBase16(headerStr.subSequence(0, TRACE_ID_SIZE));

    int traceOptionsPos = headerStr.indexOf(TRACE_OPTION_DELIMITER, TRACE_ID_SIZE);
    CharSequence spanIdStr = headerStr.subSequence(SPAN_ID_START_POS, traceOptionsPos < 0 ? headerStr.length() : traceOptionsPos);

    SpanId spanId = longToSpanId(UnsignedLongs.parseUnsignedLong(spanIdStr.toString(), 10));
    TraceOptions traceOptions = OPTIONS_NOT_SAMPLED;

    if (traceOptionsPos > 0) {
        String traceOptionsStr = headerStr.substring(traceOptionsPos + TRACE_OPTION_DELIMITER_SIZE);
        if ((UnsignedInts.parseUnsignedInt(traceOptionsStr, 10) & CLOUD_TRACE_IS_SAMPLED) != 0) {
            traceOptions = OPTIONS_SAMPLED;
        }
    }

    SpanContext context = SpanContext.create(traceId, spanId, traceOptions, TRACESTATE_DEFAULT);

    try (Scope scope = tracer.spanBuilderWithRemoteParent("newSpan", context).setSpanKind(Kind.SERVER).startScopedSpan())  {
       // execute Servlet code
    }

String headerStr=req.getHeader（HEADER\u NAME）；
TraceId TraceId=TraceId.fromLowerBase16（headerStr.子序列（0，TRACE_ID_SIZE））；
int traceOptions spos=headerStr.indexOf（跟踪选项分隔符，跟踪ID大小）；
CharSequence spanIdStr=headerStr.子序列（SPAN\u ID\u START\u POS，traceOptionsPos<0？headerStr.length（）：traceOptionsPos）；
SpanId SpanId=longToSpanId（UnsignedLongs.parseUnsignedLong（spanIdStr.toString（），10））；
TraceOptions TraceOptions=选项\u未\u采样；
如果（TraceOptions SPOS>0）{
字符串traceOptionsStr=headerStr.substring（traceOptionsPos+TRACE\u选项\u分隔符\u大小）；
if（（unsignedits.parseunsignedits（traceOptionsStr，10）&CLOUD\u跟踪已采样）！=0）{
traceOptions=选项\u采样；
}
}
SpanContext context=SpanContext.create（traceId、spanId、traceOptions、tracstate\u默认值）；
try（Scope Scope=tracer.spanBuilderWithRemoteParent（“newSpan”，context）.setSpanKind（Kind.SERVER）.startScopedSpan（））{
//执行Servlet代码
}

但在谷歌云平台上，我能看到的唯一跨度是“firstSpan”，而“newSpan”在监视器中不存在。。。有人能帮我吗

多谢各位