java - How to return the new value of a public String from a private void JButton? -

i have public string in 1 class , used other classes. value of string can acquired use of jbutton. code seems right still null returned button.

below class containing public string variable , code jbutton:

public class seminar_menu extends javax.swing.jframe {     connection conn = null;     resultset rs = null;     preparedstatement ps = null;     // public string mentioned in quesiton     public string seminar_choosen;     ......      //button code     private void jbutton3actionperformed(java.awt.event.actionevent evt) {                                                  conduct_seminar consem = new conduct_seminar();         seminar_menu semen = new seminar_menu();          string message = "conduct seminar?";         string title = "conduct";         int reply =             joptionpane.showconfirmdialog(null, message, title, joptionpane.yes_no_option);          if (reply == joptionpane.yes_option)         {              seminar_choosen = title_field.gettext();              consem.setvisible(true);             semen.setvisible(false);         }         }     ......  } 

i'm using jframe form way in netbeans. there other way of returning value of seminar_choosen?

public class example {   public static class myaction extends abstractaction {     string val;     public myaction(string val) {       this.val = val;     }     public void actionperformed(actionevent ae) {       system.out.println("value: " + val);     } } 

then

jbutton = new jbutton(new example(mystring));