Dim SqlQuery As String = "SELECT COUNT(*) From users1 WHERE username = @Username AND password = MD5(@Password); "

resultSet = statement.executeQuery("SELECT * FROM cards.username WHERE username = '" + username + "' AND password = ('MD5(" + password + ")'");

resultSet = statement.executeQuery("SELECT * FROM cards.username WHERE username = '" + username + "' AND password = MD5("' + password + ")'");

String sqlQuery = "select count(*) > 0 as match_found FROM username WHERE username = ? and password = MD5(?)";
// String sqlQuery = "select count(*) > 0 as cnt FROM username WHERE username = ? and password = MD5(?)";

PreparedStatement pst = connect.prepareStatement( sqlQuery );
pst.setString( 1, username );
pst.setString( 2, password );

ResultSet rs = pst.executeQuery();
boolean loginSuccess = false;
if( rs.next() ) {
  loginSuccess = rs.getBoolean( "match_found" );
  int cnt = rs.getInt(1);
  System.out.println(cnt);
}

if(loginSuccess)
    System.out.println("yess");
else
    System.out.println("noo");

try {
                 Connection conn;
                 String dbuser = "root";
                 String dbpassw = "12345";
                 String url = "jdbc:mysql://localhost/yourdatabasename";
                 Class.forName("com.mysql.jdbc.Driver");
                 conn = DriverManager.getConnection(url,dbuser,dbpassw);
                   String username = jTextField2.getText();  // this is for user name textfield

                   String password = new String (jPasswordField1.getPassword()); // this is for your paswordfield

                   PreparedStatement rs = (PreparedStatement) conn.prepareStatement("SELECT * FROM users where username=?  and password=?");
                   rs.setString(1,username );
                   rs.setString(2,password );
                 ResultSet  pst = rs.executeQuery();
                  if(pst.next()){
                       JOptionPane.showMessageDialog(null, "Login Failed ");
// do whatever you want if the login is successfull

                   }else {
                       JOptionPane.showMessageDialog(null, "Login Succesful");

                   }

            } catch (SQLException ex) {
                Logger.getLogger(myLogin.class.getName()).log(Level.SEVERE, null, ex);
            } catch (ClassNotFoundException ex) {
                Logger.getLogger(myLogin.class.getName()).log(Level.SEVERE, null, ex);
            }