public static void closeRegion(final RpcController controller,
    final AdminService.BlockingInterface admin, final ServerName server, final byte[] regionName)
    throws IOException {
    CloseRegionRequest closeRegionRequest =
      ProtobufUtil.buildCloseRegionRequest(server, regionName);
    try {
      admin.closeRegion(controller, closeRegionRequest);
    } catch (ServiceException se) {
      throw getRemoteException(se);
    }
  }
A helper to close a region given a region name using admin protocol.
hbase-client/src/main/java/org/apache/hadoop/hbase/shaded/protobuf/ProtobufUtil.java