[ERRO JAVA] --> java.lang.ClassNotFoundException: com.mysql.jdbc.Driver (estou há horas tendo tentando entender este erro, mas não cheguei a lugar nenhum)

[luisgustavoerich]

[ERRO]

mai 05, 2022 5:06:54 PM util.AcessoBD <init>
GRAVE: null
java.lang.ClassNotFoundException: com.mysql.jdbc.Driver
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:264)
    at util.AcessoBD.<init>(AcessoBD.java:19)
    at visao.Principal.<init>(Principal.java:32)
    at visao.Principal$5.run(Principal.java:249)
    at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
    at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
    at java.awt.EventQueue.access$500(EventQueue.java:97)
    at java.awt.EventQueue$3.run(EventQueue.java:709)
    at java.awt.EventQueue$3.run(EventQueue.java:703)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:76)
    at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
    at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
    at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
    at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
    at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
    at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

 

Classe AcessoBD

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.logging.Level;
import java.util.logging.Logger;

public class AcessoBD {

    private String stringDeConexao;
    private Connection conexao;

    public AcessoBD(String nomeBanco) {
        stringDeConexao = "jdbc:mysql://localhost/" + nomeBanco
                + "?user=root";

        try {
            Class.forName("com.mysql.jdbc.Driver");  //[linha 19 AcessoBD]
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(AcessoBD.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void conectar() {
        try {
            conexao = DriverManager.getConnection(stringDeConexao);
            System.out.println("Conexão efetuada com sucesso");
        } catch (SQLException ex) {
            Logger.getLogger(AcessoBD.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public void desconectar() {
        try {
            conexao.close();
            System.out.println("Conexão encerrada com sucesso");
        } catch (SQLException ex) {
            Logger.getLogger(AcessoBD.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    public Connection getConexao() {
        return conexao;
    }

}
 

Classe Principal

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package visao;

import java.util.ArrayList;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.DefaultListModel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;
import modelo.Sorvete;
import negocio.SorveteDAO;
import util.AcessoBD;

/**
 *
 * @author fernando
 */
public class Principal extends javax.swing.JFrame {

    private DefaultListModel<Sorvete> modelo;
    public static ArrayList<Sorvete> sorvetes = new ArrayList<>();
    private AcessoBD acessoBD;
    public static SorveteDAO sorveteDAO;
    
    public Principal() {
        initComponents();
        
        acessoBD = new AcessoBD("trabalhopv"); //[linha 32 Principal]
        sorveteDAO = new SorveteDAO(acessoBD);
        modelo = new DefaultListModel();
        lista.setModel(modelo);
    }

    /**
     * This method is called from within the constructor to initialize the form.
     * WARNING: Do NOT modify this code. The content of this method is always
     * regenerated by the Form Editor.
     */
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">                          
    private void initComponents() {

        jTabbedPane1 = new javax.swing.JTabbedPane();
        jPanel1 = new javax.swing.JPanel();
        jLabel1 = new javax.swing.JLabel();
        jLabel2 = new javax.swing.JLabel();
        campoSabor = new javax.swing.JTextField();
        botaoGravar = new javax.swing.JButton();
        jLabel3 = new javax.swing.JLabel();
        campoFabricacao = new javax.swing.JTextField();
        jPanel2 = new javax.swing.JPanel();
        jToolBar1 = new javax.swing.JToolBar();
        botaoRemover = new javax.swing.JButton();
        botaoEditar = new javax.swing.JButton();
        jScrollPane1 = new javax.swing.JScrollPane();
        lista = new javax.swing.JList<>();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jTabbedPane1.addChangeListener(new javax.swing.event.ChangeListener() {
            public void stateChanged(javax.swing.event.ChangeEvent evt) {
                jTabbedPane1StateChanged(evt);
            }
        });

        jLabel1.setFont(new java.awt.Font("Tahoma", 0, 24)); // NOI18N
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
        jLabel1.setText("Sorveteria");

        jLabel2.setText("Sabor:");

        botaoGravar.setText("Gravar");
        botaoGravar.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                botaoGravarActionPerformed(evt);
            }
        });

        jLabel3.setText("Data de Fabricação:");

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jLabel1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addComponent(jLabel3)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(campoFabricacao, javax.swing.GroupLayout.PREFERRED_SIZE, 80, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 80, Short.MAX_VALUE)
                        .addComponent(botaoGravar))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addComponent(jLabel2)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addComponent(campoSabor)))
                .addContainerGap())
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addComponent(jLabel1)
                .addGap(18, 18, 18)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel2)
                    .addComponent(campoSabor, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(18, 18, 18)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                    .addComponent(jLabel3)
                    .addComponent(botaoGravar)
                    .addComponent(campoFabricacao, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
                .addGap(0, 96, Short.MAX_VALUE))
        );

        jTabbedPane1.addTab("Cadastro", jPanel1);

        jToolBar1.setFloatable(false);
        jToolBar1.setRollover(true);

        botaoRemover.setIcon(new javax.swing.ImageIcon(getClass().getResource("/imagens/delete.png"))); // NOI18N
        botaoRemover.setToolTipText("Excluir");
        botaoRemover.setFocusable(false);
        botaoRemover.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        botaoRemover.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM);
        botaoRemover.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                botaoRemoverActionPerformed(evt);
            }
        });
        jToolBar1.add(botaoRemover);

        botaoEditar.setIcon(new javax.swing.ImageIcon(getClass().getResource("/imagens/editar32.png"))); // NOI18N
        botaoEditar.setToolTipText("Editar");
        botaoEditar.setFocusable(false);
        botaoEditar.setHorizontalTextPosition(javax.swing.SwingConstants.CENTER);
        botaoEditar.setVerticalTextPosition(javax.swing.SwingConstants.BOTTOM);
        botaoEditar.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                botaoEditarActionPerformed(evt);
            }
        });
        jToolBar1.add(botaoEditar);

        lista.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
        jScrollPane1.setViewportView(lista);

        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jToolBar1, javax.swing.GroupLayout.DEFAULT_SIZE, 346, Short.MAX_VALUE)
            .addComponent(jScrollPane1)
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addComponent(jToolBar1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 157, Short.MAX_VALUE))
        );

        jTabbedPane1.addTab("Listagem", jPanel2);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jTabbedPane1)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(jTabbedPane1)
        );

        pack();
        setLocationRelativeTo(null);
    }// </editor-fold>                        

    private void botaoGravarActionPerformed(java.awt.event.ActionEvent evt) {                                            
        //CADASTRAR O SORVETE NO BANCO
        sorvetes.add(
                new Sorvete(
                        campoSabor.getText(),
                        campoFabricacao.getText()
                )
        );
        campoSabor.setText("");
        campoFabricacao.setText("");
        Sorvete sorvete = new Sorvete(
                campoSabor.getText(),
                campoFabricacao.getText()
        );
        Principal.sorveteDAO.inserir(sorvete);
        dispose();
    }                                           

    private void jTabbedPane1StateChanged(javax.swing.event.ChangeEvent evt) {                                          
        if (jTabbedPane1.getSelectedIndex() == 1) {
            modelo.removeAllElements();

            //AQUI A LISTA DE SORVETES DEVE SER ALIMENTADA            
            for (Sorvete i : Principal.sorveteDAO.listar()) {
                modelo.addElement(i);
            }
            lista.setModel(modelo);
            //----------------------------------------------
        }
    }                                         

    private void botaoRemoverActionPerformed(java.awt.event.ActionEvent evt) {                                             
        while (lista.getSelectedIndex() != -1) {
            Principal.sorveteDAO.apagar(lista.getSelectedValue());
            modelo.removeElementAt(lista.getSelectedIndex());
        }
    }                                            

    private void botaoEditarActionPerformed(java.awt.event.ActionEvent evt) {                                            
        if (lista.getSelectedIndex() != -1) {
            new Edicao(this, true, lista.getSelectedValue()).setVisible(true);
            repaint();
        }
    }                                           

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        try {
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(Principal.class.getName()).log(Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            Logger.getLogger(Principal.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            Logger.getLogger(Principal.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedLookAndFeelException ex) {
            Logger.getLogger(Principal.class.getName()).log(Level.SEVERE, null, ex);
        }

        /* Create and display the form */
        java.awt.EventQueue.invokeLater(new Runnable() {
            public void run() {
                new Principal().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JButton botaoEditar;
    private javax.swing.JButton botaoGravar;
    private javax.swing.JButton botaoRemover;
    private javax.swing.JTextField campoFabricacao;
    private javax.swing.JTextField campoSabor;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JTabbedPane jTabbedPane1;
    private javax.swing.JToolBar jToolBar1;
    private javax.swing.JList<Sorvete> lista;
    // End of variables declaration                   
}

Editado Maio 5, 2022 por luisgustavoerich