我正在尝试使用preparedstatement对几个记录进行批插入。然而，每当我调用resultset的next时，我总是得到false

public ResultSet insert_into_batch(ArrayList<Movie> values) throws SQLException
{
    conn.setAutoCommit(false);
    ArrayList<String> added = new ArrayList<String>();
    String stmt = "INSERT INTO movies (id,title,year,director) VALUES (?,?,?,?)";
    PreparedStatement psInsertRecord = conn.prepareStatement(stmt, Statement.RETURN_GENERATED_KEYS);
    for (Movie movie : values)
    {
        if (!added.contains(movie.getId())) {
            added.add(movie.getId());
            psInsertRecord.setString(1, movie.getId());
            psInsertRecord.setString(2, movie.getTitle());
            psInsertRecord.setInt(3, movie.getYear());
            psInsertRecord.setString(4, movie.getDirector());
            psInsertRecord.addBatch();
        }
    }
    psInsertRecord.executeBatch();
    conn.commit();
    conn.setAutoCommit(true);
    return psInsertRecord.getGeneratedKeys();
}