@GET
  @Path("/orphan-regions-on-fs")
  public List<HbckOrphanRegionsOnFS> getOrphanRegionsOnFS() {
    return hbckReport.getOrphanRegionsOnFS().entrySet().stream()
      .map(obj1 -> new HbckOrphanRegionsOnFS(obj1.getKey(), obj1.getValue().toString()))
      .collect(Collectors.toList());
  }
The root object exposing hbck.jsp page as JSON Output.
hbase-server/src/main/java/org/apache/hadoop/hbase/master/http/hbck/resource/HbckMetricsResource.java