有一个喷口，每个滴答上的喷口通向postgre数据库并读取另外一行。喷口代码如下所示：

class RawDataLevelSpout extends BaseRichSpout implements Serializable {

private int counter;

SpoutOutputCollector collector;

@Override
public void declareOutputFields(OutputFieldsDeclarer declarer) {
    declarer.declare(new Fields("col1", "col2"));
}

@Override
public void open(Map map, TopologyContext context, SpoutOutputCollector spoutOutputCollector) {
    collector = spoutOutputCollector;
}

private Connection initializeDatabaseConnection() {

    try {
        Class.forName("org.postgresql.Driver");
        Connection connection = null;
        connection = DriverManager.getConnection(
                DATABASE_URI,"root", "root");
        return connection;
    } catch (ClassNotFoundException e) {
        e.printStackTrace();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return null;
}

@Override
public void close() {

}

@Override
public void nextTuple() {
    List<String> values = new ArrayList<>();

    PreparedStatement statement = null;
    try {
        Connection connection = initializeDatabaseConnection();
        statement = connection.prepareStatement("SELECT * FROM table1 ORDER BY col1 LIMIT 1 OFFSET ?");
        statement.setInt(1, counter++);
        ResultSet resultSet = statement.executeQuery();
        resultSet.next();
        ResultSetMetaData resultSetMetaData = resultSet.getMetaData();
        int totalColumns = resultSetMetaData.getColumnCount();
        for (int i = 1; i <= totalColumns; i++) {
            String value = resultSet.getString(i);
            values.add(value);
        }

        connection.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
    collector.emit(new Values(values.stream().toArray(String[]::new)));
}

}
在ApacheStorm中，在喷口中实现连接池的标准方法是什么？此外，是否可以在集群拓扑中的多个运行示例之间以某种方式同步coutner变量accross？