Could not find or load main class when trying to connect MariaDB

Question

Error: Could not find or load main class...

What am I doing wrong when trying to connect Maria DB in java? I'm a novice developer in java so don't be rude...

Am I compiling in a wrong way this file? Also I tried to download mysql and mariaDb drivers but still had no success...I think the driver is not the problem, appreciate all the guidance and help.

This is all my code:

Panaderia.java

package proyecto;

import javax.swing.JFrame;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JButton;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import java.awt.FlowLayout;
import java.sql.*;

public class Panaderia extends JFrame implements ActionListener{
    JTextArea tablas_ta;
    JTextArea registros_ta;
    JButton consultarTablas_btn;
    JButton consultarRegistros_btn;
    JTextField textField;

    /*
     * Método constructor
     **/
    public Panaderia(){

        super("Ejemplo de Java + MySQL");

        //Configurar la operación de salida por defecto para JFrame
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        this.setSize(800,750);

        setLayout(new FlowLayout());

        consultarTablas_btn = new JButton("Consultar tablas");
        consultarTablas_btn.setActionCommand("ConsultarTablas");
        add(consultarTablas_btn); 

        tablas_ta = new JTextArea(10, 70);
        add(tablas_ta);

        textField = new JTextField(30);
        add(textField);

        consultarRegistros_btn = new JButton("Consultar registros");
        consultarRegistros_btn.setActionCommand("ConsultarRegistros");
        add(consultarRegistros_btn); 

        registros_ta = new JTextArea(10, 70);
        add(registros_ta);


        // Usar este objeto como Manejador de eventos 
        consultarTablas_btn.addActionListener(this);
        consultarRegistros_btn.addActionListener(this);
        textField.addActionListener(this);


        this.setVisible(true);
    }


    public static void main(String[] args) {

        Panaderia mjf = new Panaderia();
    }

    @Override
    public void actionPerformed(ActionEvent evento) {
        String db, dbuser, pass;
            db = "ejemplos";//cambiar por el nombre de la base de datos que desean utilizar
            dbuser = "root";
            pass = "";
        if(evento.getActionCommand()=="ConsultarTablas") {  

            try {       
                Class.forName("com.mysql.jdbc.Driver");

                Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/"+db, dbuser, pass);

                Statement stmt = con.createStatement();  
                ResultSet rs = stmt.executeQuery("SHOW TABLES");  

                while( rs.next() ) {
                    tablas_ta.append( rs.getString(1) + "\n");
                }

                tablas_ta.append("\n");

                con.close();

            } catch(Exception e) { 
                System.out.println(e);
            }

        }

        if(evento.getActionCommand()=="ConsultarRegistros") {   

            try {       
                Class.forName("com.mysql.jdbc.Driver");

                Connection con = DriverManager.getConnection(
                    "jdbc:mysql://localhost:3306/"+db, dbuser, pass);

                Statement stmt = con.createStatement(); 

                ResultSet rs = stmt.executeQuery("SELECT * FROM "+textField.getText());  

                String registro = "";

                while( rs.next() ) {
                    for(int i=1;i<=rs.getMetaData().getColumnCount();i++){
                        registro = registro + "\t" + rs.getString(i);
                    }
                    registros_ta.append( registro +"\n");
                    registro = "";
                }

                registros_ta.append("\n");

                con.close();

            } catch(Exception e) { 
                System.out.println(e);
            }

        }


    }   
}

The error showing in terminal is:

How should you fix it?

Answer 1

1. In order to run your application from the command Line your Panaderia.java and the mysql.jar file should reside in the same folder. If not you have to give the path aswel.
2. so the proyecto folder contains Panaderia.java and mysql.jar file.Open command line from the root folder where you see the proyecto folder

1. To compile your code : javac -cp proyecto\mysql-connector-java-5.1.49.jar; proyecto\Panaderia.java
2. To run : java -cp proyecto\mysql-connector-java-5.1.49.jar; proyecto.Panaderia

Hope this will help you.

Answer 2

Your code seems correct. I had run on my eclipse. The only thing, you have not supplied a password for the database. I will advise you to move to one of these IDE - Eclipse or Netbeans. Compiling on the command line is time taking and not useful.