@Get("/api/v2/spans")
    @Blocking
    public AggregatedHttpResponse getSpanNames(@Param("serviceName") String serviceName) throws IOException {
        List<String> spanNames = getZipkinQueryDAO().getSpanNames(serviceName);
        return cachedResponse(serviceCount > 3, spanNames);
    }
Reference from zipkin2.server.internal.ZipkinQueryApiV2 for the API consistent.
oap-server/server-query-plugin/zipkin-query-plugin/src/main/java/org/apache/skywalking/oap/query/zipkin/handler/ZipkinQueryHandler.java