java - Adding items to an already existing jlist from another class -

i have jlist (named jlist1) created using desing mode netbeans ide, , want add items list using secondary class parses big xml list , gets data it. problem dont understand how this, tried lot of different codes, tried model too, cant right. new java (and programming too), , dont understand if like
string[] ar = {"one", "two", "three"};
jlist jlist1 = new jlist(ar);
created new jlist instead of using created one, no ?

created using desing mode netbeans ide, 

• maybe not idea prisonier of code generated

• add new item defaultlistmodel

and want add items list using secondary class parses big xml list , gets data it.

• sounds have issue concurency in swing, updates visible swing gui must done on edt

• use swingworker#publish() long , hard job (which parses big xml list , gets data it.)

for example, add new item defaultlistmodel

import javax.swing.*; import java.awt.*; import java.awt.event.*;  public class testing extends jframe {      private static final long serialversionuid = 1l;     private defaultlistmodel listmodel = new defaultlistmodel();     private jlist list = new jlist(listmodel);     private int currentselectedrow = 0;     private int xx = 0;      public testing() {         setlocation(400, 300);         setdefaultcloseoperation(exit_on_close);         (int x = 0; x < 9; x++) {             listmodel.addelement("" + x);             xx++;         }         jscrollpane sp = new jscrollpane(list);         add(sp, borderlayout.center);         jbutton btn1 = new jbutton("reset model castingmodel");         add(btn1, borderlayout.north);         btn1.addactionlistener(new actionlistener() {             @override             public void actionperformed(actionevent ae) {                 list.clearselection();                 defaultlistmodel model = (defaultlistmodel) list.getmodel();                 model.removeallelements();                  // note swing gui default freeze if removed more                  // 999 elemets jlist or underlaying xxxlistmodel,                  // use repeatly actions swingtimer on short period                 (int x = 0; x < 9; x++) {                     model.addelement("" + (x + xx));                     xx++;                 }                 list.setmodel(model);             }         });          jbutton btn2 = new jbutton("reset model directly model");         add(btn2, borderlayout.south);         btn2.addactionlistener(new actionlistener() {             @override             public void actionperformed(actionevent ae) {                 list.clearselection();                 listmodel.removeallelements();                 (int x = 0; x < 9; x++) {                     listmodel.addelement("" + (x + xx));                     xx++;                 }             }         });         pack();     }      public static void main(string[] args) {         swingutilities.invokelater(new runnable() {             @override             public void run() {                 new testing().setvisible(true);             }         });     } }