GUIFrame

public class GUIFrame extends javax.swing.JFrame {
    public GUIFrame() {
        initComponents();
    }
    @SuppressWarnings("unchecked")
    // <editor-fold defaultstate="collapsed" desc="Generated Code">
    private void initComponents() {

        Label = new javax.swing.JLabel();
        TextField = new javax.swing.JTextField();
        ComboBox = new javax.swing.JComboBox<>();
        Button = new javax.swing.JButton();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);

        Label.setText("Label");

        ComboBox.setModel(new javax.swing.DefaultComboBoxModel<>(new String[] { "1", "2", "3", "4" }));
        ComboBox.addItemListener(new java.awt.event.ItemListener() {
            public void itemStateChanged(java.awt.event.ItemEvent evt) {
                ComboBoxItemStateChanged(evt);
            }
        });

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

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
                .addContainerGap()
                .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addComponent(ComboBox, javax.swing.GroupLayout.Alignment.TRAILING, 0, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addComponent(TextField, javax.swing.GroupLayout.Alignment.TRAILING)
                    .addComponent(Label, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
                .addContainerGap())
            .addGroup(layout.createSequentialGroup()
                .addGap(163, 163, 163)
                .addComponent(Button)
                .addContainerGap(165, Short.MAX_VALUE))
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(layout.createSequentialGroup()
                .addContainerGap()
                .addComponent(Label)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(TextField, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(ComboBox, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 193, Short.MAX_VALUE)
                .addComponent(Button)
                .addContainerGap())
        );

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

    private void ComboBoxItemStateChanged(java.awt.event.ItemEvent evt) {
        // TODO add your handling code here:
        String selectedValue = ComboBox.getSelectedItem().toString();

    // Установка текста для Label в зависимости от выбранной цифры
        switch (selectedValue) {
            case "1":
                Label.setText("Текст для цифры 1");
                break;
            case "2":
                Label.setText("Текст для цифры 2");
                break;
            case "3":
                Label.setText("Текст для цифры 3");
                break;
            case "4":
                Label.setText("Текст для цифры 4");
                break;
            default:
                Label.setText("Другой текст");
                break;
        }
    }

    private void ButtonActionPerformed(java.awt.event.ActionEvent evt) {
        // TODO add your handling code here:
        String title = TextField.getText();
        setTitle(title);
    }

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

    // Variables declaration - do not modify
    private javax.swing.JButton Button;
    private javax.swing.JComboBox<String> ComboBox;
    private javax.swing.JLabel Label;
    private javax.swing.JTextField TextField;
    // End of variables declaration
}