public static void release(PreparedStatement ps,ResultSet rs) {
		try {
			if (conn != null) {
				conn.close();
				conn = null;
			}
			if (ps != null) {
				ps.close();
				ps = null;
			}
			if (rs != null) {
				rs.close();
				rs = null;
			}
		} catch (SQLException e) {
			e.printStackTrace();
		}
	}