4.22

/**
 * 建立站点名称和对应的ID的哈希表
 */
public static Map<String, Integer> buildStationIdMap() {
    Connection connection = JDBCUtils.getConn();
    Map<String, Integer> stationIds = new HashMap<>();

    try {
        String sql = "SELECT Starting_Station, Terminus_Station FROM station ";

        // 从数据库中检索起始站和终点站
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery(sql);

        int currentId = 0;

        // 填充stationIds map 并找到最大的站点ID
        while (resultSet.next()) {
            String startingStation = resultSet.getString("Starting_Station");
            String terminusStation = resultSet.getString("Terminus_Station");
            if (!stationIds.containsKey(startingStation)) {
                stationIds.put(startingStation, currentId++);
            }
            if (!stationIds.containsKey(terminusStation)) {
                stationIds.put(terminusStation, currentId++);
            }
        }

    } catch (SQLException e) {
        e.printStackTrace();
        // 在这里处理任何可能的异常...
    } finally {
        // 关闭资源
        try {
            if (connection != null) {
                connection.close();
            }
            // 关闭 statement 和 resultSet
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    // 返回填充后的站点名称和对应的ID的哈希表
    return stationIds;
}