Java基础知识05-mysql

Java操作mysql,指定返回的类型

    public Map<String, GtStation> getGtAllStation() {
        return mysqlJdbcTemplate.query("SELECT AREA_CODE,STATIONID,STATIONNAME,ESTLGTUD,NORLATUD FROM gt_station;", new AllGtStation());
    }
#创建内部类，指定返回的类型
    class AllGtStation implements ResultSetExtractor<Map<String, GtStation>> {
        @Override
        public Map<String, GtStation> extractData(ResultSet result) throws SQLException, DataAccessException {
            Map<String, GtStation> stationMap = new HashMap<>();
            while (result.next()) {
                GtStation station = new GtStation();
                String area_code = result.getString("AREA_CODE");
                String stationid = result.getString("STATIONID");
                String stationname = result.getString("STATIONNAME");
                float estlgtud = result.getFloat("ESTLGTUD");
                float norlatud = result.getFloat("NORLATUD");
                station.setAreaCode(area_code);
                station.setStationId(stationid);
                station.setStationName(stationname);
                station.setLg(estlgtud);
                station.setLt(norlatud);
                stationMap.put(stationid, station);
            }
            return stationMap;
        }
    }