java - How to update JList and JTextfield with database HSQLDB? -

i use eclipse , database hsqldb. have jframe 3 jpanel.

in first jpanel, have 3 jlist, category, brands , product.

in database, have table category (id, name) brands (id, name) product (id, product, price, description, quantity + foreign key on category , brands).

i started coding can not when select 1 item in jlist category , brand, have bring result in product (one item or multiple) , when select 1 item in jlist product, have bring result in jpanel informations (price, description , quantity).

below code of ihm

package ihm;  import javax.swing.*; import javax.swing.event.listselectionevent; import javax.swing.event.listselectionlistener;  import donnees.categories; import donnees.categoriescellrenderer; import donnees.categorieslistmodel; import donnees.marques; import donnees.marquescellrenderer; import donnees.marqueslistmodel; import donnees.produits; import donnees.produitscellrenderer; import donnees.produitslistmodel; import fabriques.fabcategories; import fabriques.fabmarques;  import java.awt.*; import java.sql.connection; import java.sql.drivermanager; import java.sql.sqlexception;  public class fenetre {  static connection conn;      public static void main(string[] args) throws classnotfoundexception, sqlexception {         class.forname("org.hsqldb.jdbcdriver");         conn=drivermanager.getconnection("jdbc:hsqldb:file:bdd/bdd","sa","");          fabcategories.getinstance().demarrerconnexion(conn);         fabmarques.getinstance().demarrerconnexion(conn);          jframe f = new jframe("gestion des produits");         f.setdefaultcloseoperation(windowconstants.exit_on_close);         container contentpane = f.getcontentpane();          contentpane.setlayout(new gridlayout(1,2,3, 3));          jpanelproduit jpanelproduit = new jpanelproduit();         jpanelinformations jpanelinformations = new jpanelinformations();         jpanelventes jpanelventes = new jpanelventes();          jpanelproduit.setbackground(color.green);         jpanelproduit.setbackground(color.yellow);         jpanelventes.setbackground(color.pink);          contentpane.add(jpanelproduit);         contentpane.add(jpanelinformations);         contentpane.add(jpanelventes);          f.setsize(700,700);         f.pack();         f.setvisible(true);     } }  class jpanelproduit extends jpanel implements listselectionlistener {      public jpanelproduit() throws sqlexception {         jpanel panelproduit = new jpanel();         setlayout(new gridlayout(5,2,5,5));          string labelcat = "categories";         string labelmark = "marques";             string labelprod = "produits";           jlist<categories> listcategories= new jlist<categories> ();         jlist<marques> listmarques= new jlist<marques> ();         jlist<produits> listproduits= new jlist<produits> ();          jscrollpane listcategoriesscrollpane = new jscrollpane (listcategories);                  add(new jlabel(labelcat));         add(new jscrollpane(listcategoriesscrollpane));         listcategories.setcellrenderer(new categoriescellrenderer());;         listcategories.setmodel(new categorieslistmodel());         listcategories.addlistselectionlistener((this));          add(new jlabel(labelmark));         jscrollpane listmarquesscrollpane = new jscrollpane (listmarques);                 add(new jscrollpane(listmarquesscrollpane));         listmarques.setcellrenderer(new marquescellrenderer());         listmarques.setmodel(new marqueslistmodel());         listmarques.addlistselectionlistener(this);          add(new jlabel(labelprod));         jscrollpane listproduitscrollpane = new jscrollpane (listproduits);                 add(new jscrollpane(listproduitscrollpane));         listproduits.addlistselectionlistener(this);      }      @override     public void valuechanged(listselectionevent arg0) {         // todo auto-generated method stub      } }  class jpanelinformations extends jpanel {      public jpanelinformations() {         //jpanel panelinformation = new jpanel(); remove new instance of panel         setlayout(new gridlayout(7,1,5,5));           jlabel labelinfo = new jlabel ("information");         jlabel labelprix = new jlabel ("prix");         jlabel labeldesc = new jlabel ("description");             jlabel labelquant = new jlabel ("quantite");             jtextfield fieldprix = new jtextfield (20);          jtextarea fielddesc = new jtextarea (20, 20);          jtextfield fieldquantite = new jtextfield (20);           add(labelinfo); //remove panelinformation.         add(labelprix);//remove panelinformation.         add(fieldprix);//remove panelinformation.         add(labeldesc);//remove panelinformation.         add(fielddesc);//remove panelinformation.         add(labelquant);//remove panelinformation.         add(fieldquantite);//remove panelinformation.     } }  class jpanelventes extends jpanel {      public jpanelventes() {         //jpanel panelventes = new jpanel(); remove new instance of jpanel         setlayout(new gridlayout(8,1,5,5));         jlabel labelvendre = new jlabel ("vendre");         jlabel labelqte = new jlabel ("quantite");         jlabel labelpromo = new jlabel ("promotion");         jlabel labeltot = new jlabel ("total");             jtextfield fieldqte = new jtextfield (20);          jtextfield fieldpromoeuros = new jtextfield (20);          jtextfield fieldpromopourcent = new jtextfield (20);          jtextfield fieldtotal = new jtextfield (20);            add (labelvendre); //remove panelventes         add (labelqte);//remove panelventes         add (fieldqte);//remove panelventes         add (labelpromo);//remove panelventes         add (fieldpromoeuros);//remove panelventes         add (fieldpromopourcent);//remove panelventes         add (labeltot);//remove panelventes         add (fieldtotal);//remove panelventes     } } 

i not fetch value of item weird value, such donnees.marques@3d5bac58

how display result in jlist brands

listcategories.addmouselistener(new mouseadapter() {             @override             public void mouseclicked(mouseevent arg0) {                 categories selectedcategories =      listcategories.getselectedvalue();                 system.out.println(selectedcategories);             }         });          listmarques.addmouselistener(new mouseadapter() {             @override             public void mouseclicked(mouseevent arg0) {                 marques selectedmarques = listmarques.getselectedvalue();                 system.out.println(selectedmarques);             }         });