public UserDTO login(UserDTO user) { UserDTO dto = null; try (Connection conn = Conn.getConnection(); PreparedStatement pstmt = conn.prepareStatement( "select user_id,name,auth from user where user_id=? and password=?"); ) { pstmt.setInt(1, user.getUid()); pstmt.setString(2, Sha256.encrypt(user.getPassword())); // pstmt.setString(2, user.getPassword()); try (ResultSet rs = pstmt.executeQuery(); ) { if (rs.next()) { dto = new UserDTO(); dto.setUid(rs.getInt("user_id")); dto.setName(rs.getString("name")); dto.setAuth(rs.getString("auth")); } } catch (Exception e) { e.printStackTrace(); } } catch (Exception e) { e.printStackTrace(); } return dto; }