How to make a button read the text field number

Question

    /**
     * Creates new form Calculadora
     */
    public Calculadora() {
        initComponents();
    }

    /**
     * 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() {

        jPanel1 = new javax.swing.JPanel();
        j1 = new javax.swing.JTextField();
        j2 = new javax.swing.JTextField();
        jBotao = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());

        j1.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                j1ActionPerformed(evt);
            }
        });

        jBotao.setText("OK");
        jBotao.addActionListener(new java.awt.event.ActionListener() {
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                jBotaoActionPerformed(evt);
            }
        });

        javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
        jPanel1.setLayout(jPanel1Layout);
        jPanel1Layout.setHorizontalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                .addContainerGap(144, Short.MAX_VALUE)
                .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(jBotao, javax.swing.GroupLayout.PREFERRED_SIZE, 146, javax.swing.GroupLayout.PREFERRED_SIZE)
                    .addGroup(javax.swing.GroupLayout.Alignment.LEADING, jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.TRAILING)
                        .addComponent(j1, javax.swing.GroupLayout.PREFERRED_SIZE, 146, javax.swing.GroupLayout.PREFERRED_SIZE)
                        .addComponent(j2, javax.swing.GroupLayout.PREFERRED_SIZE, 146, javax.swing.GroupLayout.PREFERRED_SIZE)))
                .addGap(127, 127, 127))
        );
        jPanel1Layout.setVerticalGroup(
            jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(jPanel1Layout.createSequentialGroup()
                .addGap(68, 68, 68)
                .addComponent(j1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(33, 33, 33)
                .addComponent(j2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addGap(71, 71, 71)
                .addComponent(jBotao)
                .addContainerGap(94, Short.MAX_VALUE))
        );

        getContentPane().add(jPanel1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, -1, -1));

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

    private void jBotaoActionPerformed(java.awt.event.ActionEvent evt) {                                       
   
     
        
    }                                      

    private void j1ActionPerformed(java.awt.event.ActionEvent evt) {                                   
        // TODO add your handling code here:
    }                                  

                                      
    /**
     * @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(Calculadora.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (InstantiationException ex) {
            java.util.logging.Logger.getLogger(Calculadora.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (IllegalAccessException ex) {
            java.util.logging.Logger.getLogger(Calculadora.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
        } catch (javax.swing.UnsupportedLookAndFeelException ex) {
            java.util.logging.Logger.getLogger(Calculadora.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 Calculadora().setVisible(true);
            }
        });
    }

    // Variables declaration - do not modify                     
    private javax.swing.JTextField j1;
    private javax.swing.JTextField j2;[![][1]][1]
    private javax.swing.JButton jBotao;
    public javax.swing.JPanel jPanel1;
    // End of variables declaration                   
}


  [1]: https://i.stack.imgur.com/y82ga.png

Answer 1

private void jBotaoActionPerformed(java.awt.event.ActionEvent evt) {                                       
    int numero = Integer.parseInt(j1.getText()); //aqui a variavel numero é inteira e guarda o número digitado no campo de texto j1
    
    j2.setText(String.valueOf(numero)); //aqui  é uma demonstação do uso da variável inteira numero sendo convertida para String (String.valueOf(numero)) e sendo apresentada no campo j2, que poderia ser um Label.... fica apenas de exemplo
}