code: @Deprecated
      public static void releaseConnection(final Connection con) {
          // If we had failed allocating the connection, insure we don't try to count it or close it.
          // UP-4446
          if (con != null) {
              try {
                  activeConnections.decrementAndGet();
  
                  con.close();
              } catch (Exception e) {
                  if (LOG.isWarnEnabled()) LOG.warn("Error closing Connection: " + con, e);
              }
          }
      }
docs: Releases database connection. Unlike the underlying connection.close(), this method does not
  throw SQLException or any other exception. It will fail silently from the perspective of
  calling code, logging errors using Commons Logging.
  
  @param con a database Connection object
  @deprecated Where possible code should be injected with a {@link DataSource} object via the
  Spring application context