StationRepositoryImpl.java 文件源码

/**
 * Selection of arbitrary sharing stations at specific location via lat/lon coordinates
 *
 * @param lon Longitude of the target location
 * @param lat Latitude of the target location
 * @return A descendant of SharingStation class if exists at target location
 * @throws DatabaseException if no station could be retrieved
 */
@Override
public SharingStation findByCoordinate(Double lon, Double lat, Class<? extends SharingStation> clazz) throws DatabaseException {
    String sql = "SELECT * FROM bikestation WHERE " +
                 "ST_PointFromText('POINT(' || ? || ' ' || ? || ')', 4326) = geopos " +
                 "UNION " +
                 "SELECT * FROM carstation " +
                 "WHERE ST_PointFromText('POINT(' || ? || ' ' || ? || ')', 4326) = geopos;";

    Query q = entityManager.createNativeQuery(sql, clazz);

    q.setParameter(1, lon);
    q.setParameter(2, lat);
    q.setParameter(3, lon);
    q.setParameter(4, lat);
    try {
        return (SharingStation) q.getSingleResult();
    } catch (PersistenceException e) {
        throw new DatabaseException("Unable to find Sharing Station in Database");
    }
}