Imprimir média de 2 nºs no NETBEANS usando onclick!

Programação Java
#1

Ola, sou iniciante em java, estou usando o NETBEANS e gostaria d saber qual sintaxe eu uso pra exibir um resultado numa caixa de dialogo?..

public class NewJFrame extends javax.swing.JFrame {

Integer N1, N2, media;
 String nome;  
 
    public NewJFrame() {
    initComponents();
    
    nome = (jTextField3.getText());
    N1 = Integer.parseInt(jTextField1.getText());
    N2 = Integer.parseInt(jTextField2.getText());
    media = ((N1 + N2)/2); 
}

private void initComponents() {
    jButton1 = new javax.swing.JButton();
    jTextField1 = new javax.swing.JTextField();
    jTextField2 = new javax.swing.JTextField();
    jTextField3 = new javax.swing.JTextField();

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
    jButton1.setText("jButton1");
    jButton1.addMouseListener(new java.awt.event.MouseAdapter() {
        public void mouseClicked(java.awt.event.MouseEvent evt) {
            msg(evt);
        }
    });

    org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(
        layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
        .add(layout.createSequentialGroup()
            .add(69, 69, 69)
            .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, 176, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                .add(layout.createSequentialGroup()
                    .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING, false)
                        .add(jTextField3)
                        .add(jTextField2, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, 59, Short.MAX_VALUE))
                    .add(24, 24, 24)
                    .add(jButton1)))
            .add(155, 155, 155))
    );
    layout.setVerticalGroup(
        layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
        .add(layout.createSequentialGroup()
            .add(30, 30, 30)
            .add(jTextField1, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
            .add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
                .add(layout.createSequentialGroup()
                    .add(16, 16, 16)
                    .add(jTextField2, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
                    .addPreferredGap(org.jdesktop.layout.LayoutStyle.RELATED)
                    .add(jTextField3, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE))
                .add(layout.createSequentialGroup()
                    .add(25, 25, 25)
                    .add(jButton1)))
            .addContainerGap(191, Short.MAX_VALUE))
    );
    pack();
}// </editor-fold>

private void msg(java.awt.event.MouseEvent evt) {
// TODO add your handling code here: ???

Se alguem puder me ajudar!!!

Obrigada!

#2

JOptionPane não resolve seu caso? Dá uma olhada na API!

#3