Problema com a arquitetura MVC em Java

Boa tarde, preciso de uma ajuda urgente!!

Estou usando a arquitetura MVC pela primeira vez, e não sei o que está errado no meu código. A interface gráfica roda, mas o cadastro não é salvo no banco de dados e não aparece a mensagem de cadastro concluído ou indeferido. Tampei as informações do BD com *, mas todas as informações estão corretas.

View:

package View;

public class CadastroView extends javax.swing.JFrame {
	

    /**
     * Creates new form Cadastro
     */
    public CadastroView() {
        initComponents();
        this.verSenha.setVisible(false);
         this.verSenhaConfirma.setVisible(false);
         setExtendedState(MAXIMIZED_BOTH);
    }

    /**
     * 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.
     */
    
    // <editor-fold defaultstate="collapsed" desc="Generated Code">//GEN-BEGIN:initComponents
    private void initComponents() {

        jLabel1 = new javax.swing.JLabel();
        jLabel4 = new javax.swing.JLabel();
        jPanel1 = new javax.swing.JPanel();
        jPanel2 = new javax.swing.JPanel();
        btnVoltaLogin = new javax.swing.JButton();
        jPanel3 = new javax.swing.JPanel();
        jLabel2 = new javax.swing.JLabel();
        jLabel5 = new javax.swing.JLabel();
        jLabel6 = new javax.swing.JLabel();
        txtNome = new javax.swing.JTextField();
        jLabel7 = new javax.swing.JLabel();
        txtSobrenome = new javax.swing.JTextField();
        jLabel8 = new javax.swing.JLabel();
        BoxGrau = new javax.swing.JComboBox<>();
        jLabel9 = new javax.swing.JLabel();
        txtNomeUsuario = new javax.swing.JTextField();
        jPanel4 = new javax.swing.JPanel();
        jLabel10 = new javax.swing.JLabel();
        pwdSenha = new javax.swing.JPasswordField();
        jLabel11 = new javax.swing.JLabel();
        pwdSenhaConfima = new javax.swing.JPasswordField();
        jFormattedTextField1 = new javax.swing.JFormattedTextField();
        verSenha = new javax.swing.JLabel();
        naoVerSenha = new javax.swing.JLabel();
        verSenhaConfirma = new javax.swing.JLabel();
        naoVerSenhaConfirma = new javax.swing.JLabel();

        jLabel1.setFont(new java.awt.Font("Arial Black", 1, 52)); // NOI18N
        jLabel1.setForeground(new java.awt.Color(96, 6, 69));
        jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.RIGHT);
        jLabel1.setText("LOGIN");

        jLabel4.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel4.setForeground(new java.awt.Color(82, 6, 59));
        jLabel4.setText("Nome de usuário: ");

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        jPanel1.setBackground(new java.awt.Color(222, 240, 236));

        jPanel2.setBackground(new java.awt.Color(190, 227, 219));

        btnVoltaLogin.setBackground(new java.awt.Color(171, 202, 194));
        btnVoltaLogin.setFont(new java.awt.Font("Segoe UI", 1, 24)); // NOI18N
        btnVoltaLogin.setForeground(new java.awt.Color(50, 75, 70));
        btnVoltaLogin.setText("CONTINUAR");
        btnVoltaLogin.setBorder(null);
        
        javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
        jPanel2.setLayout(jPanel2Layout);
        jPanel2Layout.setHorizontalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(btnVoltaLogin, javax.swing.GroupLayout.PREFERRED_SIZE, 206, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(648, 648, 648))
        );
        jPanel2Layout.setVerticalGroup(
            jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel2Layout.createSequentialGroup()
                .addGap(18, 18, 18)
                .addComponent(btnVoltaLogin, javax.swing.GroupLayout.PREFERRED_SIZE, 60, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap(22, Short.MAX_VALUE))
        );

        jPanel3.setBackground(new java.awt.Color(190, 227, 219));

        jLabel2.setFont(new java.awt.Font("Arial Black", 1, 52)); // NOI18N
        jLabel2.setForeground(new java.awt.Color(49, 73, 68));
        jLabel2.setHorizontalAlignment(javax.swing.SwingConstants.RIGHT);
        jLabel2.setText("CADASTRO");

        javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
        jPanel3.setLayout(jPanel3Layout);
        jPanel3Layout.setHorizontalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel3Layout.createSequentialGroup()
                .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addComponent(jLabel2, javax.swing.GroupLayout.PREFERRED_SIZE, 363, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(569, 569, 569))
        );
        jPanel3Layout.setVerticalGroup(
            jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel3Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jLabel2)
                .addContainerGap(19, Short.MAX_VALUE))
        );

        jLabel5.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel5.setForeground(new java.awt.Color(42, 62, 58));
        jLabel5.setText("Data de nascimento:");

        jLabel6.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel6.setForeground(new java.awt.Color(42, 62, 58));
        jLabel6.setText("Nome: ");

        txtNome.setBackground(new java.awt.Color(240, 255, 249));
        txtNome.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        txtNome.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Segoe UI", 0, 12), new java.awt.Color(255, 255, 255))); // NOI18N
        

        jLabel7.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel7.setForeground(new java.awt.Color(42, 62, 58));
        jLabel7.setText("Sobrenome: ");

        txtSobrenome.setBackground(new java.awt.Color(240, 255, 249));
        txtSobrenome.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        txtSobrenome.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Segoe UI", 0, 12), new java.awt.Color(255, 255, 255))); // NOI18N
        
        jLabel8.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel8.setForeground(new java.awt.Color(42, 62, 58));
        jLabel8.setText("Grau de escolaridade: ");

        BoxGrau.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        BoxGrau.setForeground(new java.awt.Color(34, 50, 47));
        BoxGrau.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "Escolha uma das opções:", "Ainda estou no Ensino Fundamental", "1º Ano do Ensino Médio", "2º Ano do Ensino Médio", "3º Ano do Ensino Médio", "Já me formei "}));
        

        jLabel9.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel9.setForeground(new java.awt.Color(42, 62, 58));
        jLabel9.setText("Confirmar senha:");

        txtNomeUsuario.setBackground(new java.awt.Color(240, 255, 249));
        txtNomeUsuario.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        txtNomeUsuario.setBorder(javax.swing.BorderFactory.createTitledBorder(null, "", javax.swing.border.TitledBorder.DEFAULT_JUSTIFICATION, javax.swing.border.TitledBorder.DEFAULT_POSITION, new java.awt.Font("Segoe UI", 0, 12), new java.awt.Color(255, 255, 255))); // NOI18N
        
        jPanel4.setBackground(new java.awt.Color(233, 246, 243));

        javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
        jPanel4.setLayout(jPanel4Layout);
        jPanel4Layout.setHorizontalGroup(
            jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 8, Short.MAX_VALUE)
        );
        jPanel4Layout.setVerticalGroup(
            jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGap(0, 0, Short.MAX_VALUE)
        );

        jLabel10.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel10.setForeground(new java.awt.Color(42, 62, 58));
        jLabel10.setText("Nome de usuário: ");

        pwdSenha.setBackground(new java.awt.Color(240, 255, 249));
        pwdSenha.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        pwdSenha.setBorder(javax.swing.BorderFactory.createTitledBorder(""));

        jLabel11.setFont(new java.awt.Font("Yu Gothic UI Semibold", 0, 27)); // NOI18N
        jLabel11.setForeground(new java.awt.Color(42, 62, 58));
        jLabel11.setText("Senha:");

        pwdSenhaConfima.setBackground(new java.awt.Color(240, 255, 249));
        pwdSenhaConfima.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N
        pwdSenhaConfima.setBorder(javax.swing.BorderFactory.createTitledBorder(""));

        jFormattedTextField1.setBackground(new java.awt.Color(240, 255, 249));
        try {
            jFormattedTextField1.setFormatterFactory(new javax.swing.text.DefaultFormatterFactory(new javax.swing.text.MaskFormatter(" ##/##/####")));
        } catch (java.text.ParseException ex) {
            ex.printStackTrace();
        }
        jFormattedTextField1.setFont(new java.awt.Font("Segoe UI", 0, 22)); // NOI18N

        verSenha.setIcon(new javax.swing.ImageIcon("C:\\Users\\user\\Desktop\\FERNANDA ESCOLA 2023\\POO\\ProjetoWinxStudies\\OlhoVerSenha.png")); // NOI18N
        verSenha.setText("jLabel3");
        

        naoVerSenha.setIcon(new javax.swing.ImageIcon("C:\\Users\\user\\Desktop\\FERNANDA ESCOLA 2023\\POO\\ProjetoWinxStudies\\OlhoNaoVerSenha.png")); // NOI18N
        naoVerSenha.setText("jLabel12");
        

        verSenhaConfirma.setIcon(new javax.swing.ImageIcon("C:\\Users\\user\\Desktop\\FERNANDA ESCOLA 2023\\POO\\ProjetoWinxStudies\\OlhoVerSenha.png")); // NOI18N
        verSenhaConfirma.setText("jLabel3");
        

        naoVerSenhaConfirma.setIcon(new javax.swing.ImageIcon("C:\\Users\\user\\Desktop\\FERNANDA ESCOLA 2023\\POO\\ProjetoWinxStudies\\OlhoNaoVerSenha.png")); // NOI18N
        naoVerSenhaConfirma.setText("jLabel12");
        

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addContainerGap())))
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addContainerGap()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jFormattedTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 406, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(txtSobrenome, javax.swing.GroupLayout.PREFERRED_SIZE, 682, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(BoxGrau, javax.swing.GroupLayout.PREFERRED_SIZE, 406, javax.swing.GroupLayout.PREFERRED_SIZE))
                        .addGap(54, 54, 54))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGap(83, 83, 83)
                                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                                    .addComponent(jLabel7, javax.swing.GroupLayout.PREFERRED_SIZE, 245, javax.swing.GroupLayout.PREFERRED_SIZE)
                                    .addComponent(jLabel6, javax.swing.GroupLayout.PREFERRED_SIZE, 245, javax.swing.GroupLayout.PREFERRED_SIZE)))
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGap(84, 84, 84)
                                .addComponent(jLabel5))
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addGap(81, 81, 81)
                                .addComponent(jLabel8)))
                        .addGap(436, 436, 436)))
                .addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(28, 28, 28)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(txtNomeUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, 634, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(pwdSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 501, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(verSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(naoVerSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE))
                            .addGroup(jPanel1Layout.createSequentialGroup()
                                .addComponent(pwdSenhaConfima, javax.swing.GroupLayout.PREFERRED_SIZE, 501, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(verSenhaConfirma, javax.swing.GroupLayout.PREFERRED_SIZE, 37, javax.swing.GroupLayout.PREFERRED_SIZE)
                                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                                .addComponent(naoVerSenhaConfirma, javax.swing.GroupLayout.PREFERRED_SIZE, 43, javax.swing.GroupLayout.PREFERRED_SIZE))))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(65, 65, 65)
                        .addComponent(jLabel10, javax.swing.GroupLayout.PREFERRED_SIZE, 245, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(67, 67, 67)
                        .addComponent(jLabel11, javax.swing.GroupLayout.PREFERRED_SIZE, 245, javax.swing.GroupLayout.PREFERRED_SIZE))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(66, 66, 66)
                        .addComponent(jLabel9, javax.swing.GroupLayout.PREFERRED_SIZE, 245, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addContainerGap(81, Short.MAX_VALUE))
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(52, 52, 52)
                    .addComponent(txtNome, javax.swing.GroupLayout.PREFERRED_SIZE, 689, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(801, Short.MAX_VALUE)))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(26, 26, 26)
                        .addComponent(jLabel6)
                        .addGap(95, 95, 95)
                        .addComponent(jLabel7)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(txtSobrenome, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 30, Short.MAX_VALUE)
                        .addComponent(jLabel5)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jFormattedTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 63, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(27, 27, 27)
                        .addComponent(jLabel8)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(BoxGrau, javax.swing.GroupLayout.PREFERRED_SIZE, 56, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 122, Short.MAX_VALUE))
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                        .addGap(18, 18, 18))
                    .addGroup(jPanel1Layout.createSequentialGroup()
                        .addGap(26, 26, 26)
                        .addComponent(jLabel10, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addComponent(txtNomeUsuario, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                        .addComponent(jLabel11, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addGap(2, 2, 2)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(pwdSenha, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(verSenha)
                            .addComponent(naoVerSenha))
                        .addGap(30, 30, 30)
                        .addComponent(jLabel9, javax.swing.GroupLayout.PREFERRED_SIZE, 46, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                        .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
                            .addComponent(pwdSenhaConfima, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(naoVerSenhaConfirma)
                            .addComponent(verSenhaConfirma))
                        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
                .addComponent(jPanel2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addContainerGap())
            .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                .addGroup(jPanel1Layout.createSequentialGroup()
                    .addGap(177, 177, 177)
                    .addComponent(txtNome, javax.swing.GroupLayout.PREFERRED_SIZE, 55, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addContainerGap(614, Short.MAX_VALUE)))
        );

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                .addContainerGap())
        );

        pack();
    }// </editor-fold>//GEN-END:initComponents
    
   
    

    /**
     * @param args the command line arguments
     */
    public static void main(String args[]) {
        /* Set the Nimbus look and feel */
        //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
        /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
         * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
         */
        try {
            for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
                if ("Nimbus".equals(info.getName())) {
                    javax.swing.UIManager.setLookAndFeel(info.getClassName());
                    break;
                }
            }
        } catch (ClassNotFoundException ex) {
            java.util.logging.Logger.getLogger(CadastroView.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(CadastroView.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(CadastroView.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(CadastroView.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        }
        //</editor-fold>

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

    // Variables declaration - do not modify//GEN-BEGIN:variables
    public  javax.swing.JComboBox<String> BoxGrau;
    public javax.swing.JButton btnVoltaLogin;
    public  javax.swing.JFormattedTextField jFormattedTextField1;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel10;
    private javax.swing.JLabel jLabel11;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JLabel jLabel7;
    private javax.swing.JLabel jLabel8;
    private javax.swing.JLabel jLabel9;
    private javax.swing.JPanel jPanel1;
    private javax.swing.JPanel jPanel2;
    private javax.swing.JPanel jPanel3;
    private javax.swing.JPanel jPanel4;
    public javax.swing.JLabel naoVerSenha;
    public javax.swing.JLabel naoVerSenhaConfirma;
    public javax.swing.JPasswordField pwdSenha;
    public static javax.swing.JPasswordField pwdSenhaConfima;
    public javax.swing.JTextField txtNome;
    public javax.swing.JTextField txtNomeUsuario;
    public  javax.swing.JTextField txtSobrenome;
    public  javax.swing.JLabel verSenha;
    public  javax.swing.JLabel verSenhaConfirma;
    // End of variables declaration//GEN-END:variables
}

Modelo.VO

package Model.VO;

public class UsuarioVO {
	
	private String nome;
	private String sobrenome;
    private String dataNascimento;
    private String nomeUsuario;
    private String senha;
    private String grauEscola;
	/**
	 * @return the nome
	 */
	public String getNome() {
		return nome;
	}
	/**
	 * @param nome the nome to set
	 */
	public void setNome(String nome) {
		this.nome = nome;
	}
	/**
	 * @return the sobrenome
	 */
	public String getSobrenome() {
		return sobrenome;
	}
	/**
	 * @param sobrenome the sobrenome to set
	 */
	public void setSobrenome(String sobrenome) {
		this.sobrenome = sobrenome;
	}
	/**
	 * @return the dataNascimento
	 */
	public String getDataNascimento() {
		return dataNascimento;
	}
	/**
	 * @param dataNascimento the dataNascimento to set
	 */
	public void setDataNascimento(String dataNascimento) {
		this.dataNascimento = dataNascimento;
	}
	/**
	 * @return the nomeUsuario
	 */
	public String getNomeUsuario() {
		return nomeUsuario;
	}
	/**
	 * @param nomeUsuario the nomeUsuario to set
	 */
	public void setNomeUsuario(String nomeUsuario) {
		this.nomeUsuario = nomeUsuario;
	}
	/**
	 * @return the senha
	 */
	public String getSenha() {
		return senha;
	}
	/**
	 * @param senha the senha to set
	 */
	public void setSenha(String senha) {
		this.senha = senha;
	}
	/**
	 * @return the grauEscola
	 */
	public String getGrauEscola() {
		return grauEscola;
	}
	/**
	 * @param grauEscola the grauEscola to set
	 */
	public void setGrauEscola(String grauEscola) {
		this.grauEscola = grauEscola;
	}

}

Modelo.DAO:

package Model.DAO;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;

import Model.VO.UsuarioVO;
import View.CadastroView;

public class CadastroDAO {
	
	public int check = 0;
	 PreparedStatement ps = null;
	 Connection conn;
	
	@SuppressWarnings({ })
	
	public void cadastrarUsuario(UsuarioVO usuario) {
	    try {
	      
	    	DriverManager.getConnection("jdbc:mysql://localhost:3306/bd_winxstudies", "****", "********");
	       
	        String cadastrar = "INSERT INTO usuario (nome, sobrenome, datanas, usuario, senha, grauescola) VALUES (?, ?, ?, ?, ?, ?)";
	        ps = conn.prepareStatement(cadastrar);
	        ps.setString(1, usuario.getNome());
	        ps.setString(2, usuario.getSobrenome());
	        ps.setString(3, usuario.getDataNascimento());
	        ps.setString(4, usuario.getNomeUsuario());
	        if (usuario.getSenha().equals(new String(CadastroView.pwdSenhaConfima.getPassword()))) {
	            ps.setString(5, usuario.getSenha());
	        }
	        ps.setString(6, usuario.getGrauEscola());
	        check = ps.executeUpdate();
	        conn.commit();
	        if (check > 0) {
	            System.out.println("Usuário cadastrado com sucesso!");
	        } else {
	            System.out.println("Falha ao cadastrar usuário.");
	        }
	    } catch (SQLException e) {
	        System.out.println("Erro ao cadastrar usuário: " + e.getMessage());
	    }
	    finally {
	        // Certifique-se de fechar a conexão e o statement
	        try {
	            if (ps != null) {
	                ps.close();
	            }
	            if (conn != null) {
	                conn.close();
	            }
	        } catch (SQLException e) {
	            e.printStackTrace();
	        }
	}
	
}
}

Vou deixar o resto em outro tópico por conta do limite de caracteres

Nessa linha, acredito que vc deveria ter atribuido a conexão criada à variável conn. Provavelmente uma exceção deve está sendo lançada quando esse código é executado.

Tentei e não funcionou mesmo assim, além disso, não apresenta nenhuma exceção quando o código roda

Do jeito que está seu código, é pra dar NullPointerException pq a variável conn estará null. Tente debugar para ver como a execução se comporta.