Singleton Pattern , java.sql.SQLException: Access denied for user 'x'@'x' (using password: YES),Why does this happen, just the singleton pattern?

Why, when I program in java, the connection to a mysql database, managed by phpmyadmin, using the Singleton Pattern design pattern, is it impossible for me to access the records of the tables in that database, because i see the message in console : "Access was denied to user 'x'" , but when I do not use the Singleton Pattern design pattern, it is possible to access the records in the tables in the 'x' database?

 public static void main(String[] args) {
        // TODO code application logic here
        String usr = "************";
        String pwd = "**********";
        String driver = "**********";
        String url = "*************";

        Connection con = null;
        PreparedStatement pstm = null;
        ResultSet rs = null;

        try{
            //parte >>> 1

            Class.forName(driver);
            con = DriverManager.getConnection(url, usr, pwd);
            //con = Uconnection.getConnection();
             //parte >>> 2

             String sql = "SELECT ***,***,***,*** FROM ***";
             pstm = con.prepareStatement(sql);
             rs = pstm.executeQuery();

             while(rs.next()){
                 System.out.print(rs.getInt("***")+" ");
                 System.out.print(rs.getString("***")+" ");
                 System.out.print(rs.getDate("***")+" ");
                 //System.out.print(rs.getString("***")+" ");
                 System.out.println(rs.getInt("***"));
             }
        }catch(Exception ex){
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }finally{
            //parte >>> 3
            try{
                if(rs != null)rs.close();
                if(pstm != null)pstm.close();
                if(con != null)con.close();
            }catch(Exception ex){
                ex.printStackTrace();
                throw new RuntimeException(ex);
            }

        }
    }

before Implements singleton pattern

 public static void main(String[] args) {        
        Connection con = null;
        PreparedStatement pstm = null;
        ResultSet rs = null;

        try{
            //parte >>> 1
            con = Uconnection.getConnection();
             //parte >>> 2

             String sql = "SELECT ***,***,***,*** FROM ***";
             pstm = con.prepareStatement(sql);
             rs = pstm.executeQuery();

             while(rs.next()){
                 System.out.print(rs.getInt("***")+" ");
                 System.out.print(rs.getString("***")+" ");
                 System.out.print(rs.getDate("***")+" ");
                 //System.out.print(rs.getString("***")+" ");
                 System.out.println(rs.getInt("***"));
             }
        }catch(Exception ex){
            ex.printStackTrace();
            throw new RuntimeException(ex);
        }finally{
            //parte >>> 3
            try{
                if(rs != null)rs.close();
                if(pstm != null)pstm.close();
                if(con != null)con.close();
            }catch(Exception ex){
                ex.printStackTrace();
                throw new RuntimeException(ex);
            }

        }
    }

after implements singleton pattern