code: public int getTransactionIsolation() throws SQLException {
          final Statement stmt = createStatement();
          try {
              final ResultSet rs = stmt.executeQuery("SELECT @@tx_isolation");
              rs.next();
              final String response = rs.getString(1);
              if (response.equals("REPEATABLE-READ")) {
                  return Connection.TRANSACTION_REPEATABLE_READ;
              }
              if (response.equals("READ-UNCOMMITTED")) {
                  return Connection.TRANSACTION_READ_UNCOMMITTED;
              }
              if (response.equals("READ-COMMITTED")) {
                  return Connection.TRANSACTION_READ_COMMITTED;
              }
              if (response.equals("SERIALIZABLE")) {
                  return Connection.TRANSACTION_SERIALIZABLE;
              }
          } finally {
              stmt.close();
          }
          throw SQLExceptionMapper.getSQLException("Could not get transaction isolation level");
      }
docs: Retrieves this <code>Connection</code> object's current transaction isolation level.
  
  @return the current transaction isolation level, which will be one of the following constants:
  <code>Connection.TRANSACTION_READ_UNCOMMITTED</code>, <code>Connection.TRANSACTION_READ_COMMITTED</code>,
  <code>Connection.TRANSACTION_REPEATABLE_READ</code>, <code>Connection.TRANSACTION_SERIALIZABLE</code>, or
  <code>Connection.TRANSACTION_NONE</code>.
  @throws java.sql.SQLException if a database access error occurs or this method is called on a closed connection
  @see #setTransactionIsolation