Communications Link Failure with JDBC and MySQL || com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

I am extremely new to Java, and we were given lines of code to connect our project to our database on phpmyadmin. When I try to run the code, it says:

com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.

This is the code:

String email = jTextFieldEmail.getText();
        String password = jTextFieldPassword.getText();
        try
        {  
            Class.forName("com.mysql.cj.jdbc.Driver");  
            Connection con = DriverManager.getConnection(  
            "jdbc:mysql://localhost:3306/cis2103","root","");              
            Statement stmt=con.createStatement();  
            String sqlCode = "select * from users where "
                    + "email='"+email+"' and password='"+password+"'";
        System.out.println(sqlCode);
            ResultSet rs=stmt.executeQuery(sqlCode);  
            
            rs.next();
            if((rs.getString("Email")).compareTo(email)==0 && 
                    (rs.getString("Password")).compareTo(password)==0)
            {
                this.setVisible(false);
                anothercalcu c = new anothercalcu();
                c.setVisible(true);            
            }
            con.close();  
        }
        catch(Exception e)
        {
            System.out.println(e);
        }

Here are the things I tried doing:

• restarted MySQL
• changed 3306 to 8080
• changed localhost to 172.0.0.1
• turned off my firewall
• added &autoReconnect=true&failOverReadOnly=false&maxReconnects=10 to the connection string
• and a lot more...

Additional info: we use XAMPP and i have a mysql connector jar file added to the library