java - Swing gui disappeared -

i working on simple gui options add,remove,write disk etc.. while coding program came problem gui start disappear , opening blank frame in design tab/editor(also in run time), tried undo multiple times , coming time point cannot undo anymore. posted code have. solution problem ?

   package nikola.lozanovski.bitola;     import java.awt.eventqueue;     import java.awt.font;     import java.awt.event.actionevent;     import java.awt.event.actionlistener;     import java.util.hashtable;     import javax.swing.jbutton;     import javax.swing.jframe;     import javax.swing.jlabel;     import javax.swing.joptionpane;     import javax.swing.jpanel;     import javax.swing.jtextfield;     import javax.swing.border.emptyborder;     public class vozenred extends jframe {         public vozenred() {         }         /**          *           */         private static final long serialversionuid = 1l;         private jpanel contentpane;         private jbutton delete;         private jbutton transporter;         private jtextfield idbox;         private jtextfield initialbox;         private jtextfield finalbox;         private jtextfield hbox;         private jtextfield pricebox;         private jtextfield agencybox;         private jtextfield savebox;         private jtextfield mbox;         private jtextfield deletebox;         private jtextfield destinationsbox;         /**          * launch application.          */         public static void main(string[] args) {             eventqueue.invokelater(new runnable() {                 public void run() {                     try {                         vozenred frame = new vozenred();                         frame.setvisible(true);                     } catch (exception e) {                         e.printstacktrace();                     }                 }             });         }         /**          * create frame.          * @return           */         public void pishi(){ //tried deleting here         hashtable<broj, elementi> h1=new hashtable<broj, elementi>();                 try                 {                 broj b=new broj(idbox.gettext());                 elementi elem=new elementi(initialbox.gettext(), finalbox.gettext(), hbox.gettext(), mbox.gettext(), pricebox.gettext(), agencybox.gettext());                 h1.put(b , elem);                 }                 catch(exception e)//i tried nullpointerexception still same                 {                     system.out.println("asd");//not realy meant                 }         } //deleting here, still no frame         public void vozenred1() {             settitle("transport me");             setdefaultcloseoperation(jframe.exit_on_close);             setbounds(100, 100, 502, 396);             contentpane = new jpanel();             contentpane.setborder(new emptyborder(5, 5, 5, 5));             setcontentpane(contentpane);             contentpane.setlayout(null);              jbutton initialdestination = new jbutton("initial destination");             initialdestination.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "input initial destination, i.e. home", "initial destination", 2);                 }             });             initialdestination.setbounds(255, 63, 194, 23);             contentpane.add(initialdestination);              jbutton finaldestination = new jbutton("final destination");             finaldestination.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "input final destination, i.e. home", "final destination", 2);                 }             });             finaldestination.setbounds(255, 97, 194, 23);             contentpane.add(finaldestination);              jbutton timedeparture = new jbutton("departure time");             timedeparture.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "input time, hours in first box, minutes in second box, i.e. 00:00", "departure time", 2);                 }             });             timedeparture.setbounds(255, 128, 194, 23);             contentpane.add(timedeparture);              jbutton ticketprice = new jbutton("ticket price");             ticketprice.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null,"input price, digits only, i.e. 100","ticketprice",2);                 }             });             ticketprice.setbounds(255, 159, 194, 23);             contentpane.add(ticketprice);              transporter = new jbutton("transport agency");             transporter.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null,"input transporter name, i.e. mytrans","transporter",2);                 }             });             transporter.setbounds(255, 190, 194, 23);             contentpane.add(transporter);              jbutton saveroute = new jbutton("save route");             saveroute.setbounds(255, 320, 194, 23);             contentpane.add(saveroute);              delete = new jbutton("delete");             delete.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                 }             });             delete.setbounds(255, 286, 194, 23);             contentpane.add(delete);              jbutton destinations = new jbutton("destinations");             destinations.setbounds(255, 252, 194, 23);             contentpane.add(destinations);              jlabel inputlabel = new jlabel("input elements");             inputlabel.setbounds(44, 11, 211, 14);             contentpane.add(inputlabel);              jlabel commandslabel = new jlabel("additional commands");             commandslabel.setbounds(44, 222, 201, 14);             contentpane.add(commandslabel);              jbutton identificationnumber = new jbutton("identification number");             identificationnumber.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent arg0) {                     joptionpane.showmessagedialog(null, "enter identification number , numbers, i.e. 0123","identificationnumber", 2);                 }             });             identificationnumber.setbounds(255, 29, 194, 23);             contentpane.add(identificationnumber);              jbutton clearall = new jbutton("clear all");             clearall.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     idbox.settext(null);                     initialbox.settext(null);                     finalbox.settext(null);                     hbox.settext(null);                     mbox.settext(null);                     pricebox.settext(null);                     agencybox.settext(null);                 }             });             clearall.setfont(new font("tahoma", font.bold, 11));             clearall.setbounds(255, 218, 194, 23);             contentpane.add(clearall);              jlabel lblhelpbuttons = new jlabel("help buttons");             lblhelpbuttons.setbounds(314, 11, 76, 14);             contentpane.add(lblhelpbuttons);              jbutton helpdestinations = new jbutton("");             helpdestinations.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "outputs destinations in new box","destinations", 2);                 }             });             helpdestinations.setbounds(459, 252, 17, 23);             contentpane.add(helpdestinations);              jbutton helpdelete = new jbutton("");             helpdelete.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "deletes selected identification","delete", 2);                 }             });             helpdelete.setbounds(459, 286, 17, 23);             contentpane.add(helpdelete);              jbutton helpsave = new jbutton("");             helpsave.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "choose directory save","save document", 2);                 }             });             helpsave.setbounds(459, 320, 17, 23);             contentpane.add(helpsave);              jbutton helpclearall = new jbutton("");             helpclearall.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     joptionpane.showmessagedialog(null, "clears boxes above","clear all", 2);                 }             });             helpclearall.setbounds(459, 218, 17, 23);             contentpane.add(helpclearall);              jbutton identificationhelpbutton = new jbutton("");             identificationhelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     idbox.settext(null);                 }             });             identificationhelpbutton.setbounds(10, 29, 17, 23);             contentpane.add(identificationhelpbutton);              jbutton initialdestinationhelpbutton = new jbutton("");             initialdestinationhelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     initialbox.settext(null);                 }             });             initialdestinationhelpbutton.setbounds(10, 60, 17, 23);             contentpane.add(initialdestinationhelpbutton);              jbutton finaldestinationhelpbutton = new jbutton("");             finaldestinationhelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent arg0) {                     finalbox.settext(null);                 }             });             finaldestinationhelpbutton.setbounds(10, 97, 17, 23);             contentpane.add(finaldestinationhelpbutton);                jbutton departuretimehelpbutton = new jbutton("");             departuretimehelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     hbox.settext(null);                     mbox.settext(null);                 }             });             departuretimehelpbutton.setbounds(10, 129, 17, 23);             contentpane.add(departuretimehelpbutton);              jbutton ticketpricehelpbutton = new jbutton("");             ticketpricehelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     pricebox.settext(null);                 }             });             ticketpricehelpbutton.setbounds(10, 159, 17, 23);             contentpane.add(ticketpricehelpbutton);              jbutton transporterhelpbutton = new jbutton("");             transporterhelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     agencybox.settext(null);                 }             });             transporterhelpbutton.setbounds(10, 190, 17, 23);             contentpane.add(transporterhelpbutton);              jlabel label = new jlabel("        :");             label.setbounds(113, 132, 39, 14);             contentpane.add(label);              jbutton savedocumentbutton = new jbutton("");             savedocumentbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     savebox.settext(null);                 }             });             savedocumentbutton.setbounds(10, 320, 17, 23);             contentpane.add(savedocumentbutton);              idbox = new jtextfield();               idbox.setbounds(44, 30, 201, 20);             contentpane.add(idbox);             idbox.setcolumns(10);              initialbox = new jtextfield();             initialbox.setcolumns(10);             initialbox.setbounds(44, 64, 201, 20);             contentpane.add(initialbox);              finalbox = new jtextfield();             finalbox.setcolumns(10);             finalbox.setbounds(44, 98, 201, 20);             contentpane.add(finalbox);              hbox = new jtextfield();             hbox.setcolumns(10);             hbox.setbounds(44, 129, 86, 20);             contentpane.add(hbox);              pricebox = new jtextfield();             pricebox.setcolumns(10);             pricebox.setbounds(44, 160, 201, 20);             contentpane.add(pricebox);              agencybox = new jtextfield();             agencybox.setcolumns(10);             agencybox.setbounds(44, 191, 201, 20);             contentpane.add(agencybox);              savebox = new jtextfield();             savebox.setcolumns(10);             savebox.setbounds(44, 321, 201, 20);             contentpane.add(savebox);              mbox = new jtextfield();             mbox.setcolumns(10);             mbox.setbounds(145, 129, 100, 20);             contentpane.add(mbox);              deletebox = new jtextfield();             deletebox.setcolumns(10);             deletebox.setbounds(44, 287, 201, 20);             contentpane.add(deletebox);              destinationsbox = new jtextfield();             destinationsbox.setcolumns(10);             destinationsbox.setbounds(44, 253, 201, 20);             contentpane.add(destinationsbox);              jbutton deletehelpbutton = new jbutton("");             deletehelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     deletebox.settext(null);                 }             });             deletehelpbutton.setbounds(10, 286, 17, 23);             contentpane.add(deletehelpbutton);              jbutton destinationhelpbutton = new jbutton("");             destinationhelpbutton.addactionlistener(new actionlistener() {                 public void actionperformed(actionevent e) {                     destinationsbox.settext(null);                 }             });             destinationhelpbutton.setbounds(10, 252, 17, 23);             contentpane.add(destinationhelpbutton);          }     } 

looks code never calls ui stuff in vozenred1().

you create vozenred object, calls empty constructor, set visible. never calling vozenred1().