public List<StreamServer> getAllStreamServers() {
    List<StreamServer> svlist = null;
    SqlSession sql =
        StreamManager.getSqlSessionFactory().openSession(TransactionIsolationLevel.SERIALIZABLE);

    try {
      StreamServerDao dao = sql.getMapper(StreamServerDao.class);
      svlist = dao.getAllStreamServers();
      sql.commit();
    } catch (Exception e) {
      sql.rollback();
      e.printStackTrace();
    } finally {
      sql.close();
    }

    return svlist;
  }
  public StreamServer getStreamServerById(long id) {
    StreamServer s = null;
    SqlSession sql =
        StreamManager.getSqlSessionFactory().openSession(TransactionIsolationLevel.SERIALIZABLE);

    try {
      StreamServerDao dao = sql.getMapper(StreamServerDao.class);
      s = dao.getStreamServerById(id);
      sql.commit();
    } catch (Exception e) {
      sql.rollback();
      e.printStackTrace();
    } finally {
      sql.close();
    }

    return s;
  }
  public boolean deleteStreamServer(long id) {
    boolean ok = true;
    SqlSession sql =
        StreamManager.getSqlSessionFactory().openSession(TransactionIsolationLevel.SERIALIZABLE);

    try {
      StreamServerDao dao = sql.getMapper(StreamServerDao.class);
      dao.deleteStreamServer(id);
      sql.commit();
    } catch (Exception e) {
      ok = false;
      sql.rollback();
      e.printStackTrace();
    } finally {
      sql.close();
    }

    return ok;
  }