good encapsulation

This code is generated by NetBeans. Although it is very simple, it is a good way to understand encapsulation.

        jButtonAdd.setText("Add");        jButtonAdd.addActionListener(new java.awt.event.ActionListener() {            public void actionPerformed(java.awt.event.ActionEvent evt) {                jButtonAddActionPerformed(evt);            }        });private void jButtonAddActionPerformed(java.awt.event.ActionEvent evt) {        // TODO add your handling code here:    }