private static String SQL_GETMAXID = "select ident_current('此处是表名') as id";

    private int getMaxID() {
        Connection conn = null;
        PreparedStatement pstmt;
        ResultSet rs;
        int id = 0;
        try {
            conn = cpool.getConnection();//在此处取得与数据库连接
            pstmt = conn.prepareStatement(SQL_GETMAXID);
            rs = pstmt.executeQuery();
            if (rs.next()) {
                id = rs.getInt(1);
            }
            rs.close();
            pstmt.close();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (conn != null) {
                try {
                    conn.close();
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        }
        return id;
    }