java - My program has a Country and State combobox, and from the state combobox it only gets the first value no matter what you choose -

so created program assignment have, creates sequential file data students. made country , state combobox, depending on country comes corresponding states, in sequential file (which .dat file) no matter state choose, in sequential file, state first one.for example if choose australia , tasmania state , state in sequential file new south wales. here code in advance

public assignment1st()  {     super("create student file");      try{         output=new dataoutputstream(new fileoutputstream("studentrec.dat"));      }       catch ( ioexception e )  {            system.err.println( "file won't open properly/n" +              e.tostring( ) );            system.exit( 1 );     }      initialize();      //*******here starts country/state combobox build**************************************     string[] countries = {"-choose","australia","belgium","brazil","canada","georgia","greece",         "india","lithuania","macedonia"};     combobox_1 = new jcombobox<object>(countries);     combobox_1.addactionlistener(this);     combobox_1.setbounds(278, 142, 92, 20);     frame.getcontentpane().add(combobox_1);       //  create sub combo box multiple models     //state combobox      combobox_2 = new jcombobox<string>();     combobox_2.additem("-choose-");     combobox_2.setbounds(452, 142, 109, 20);     frame.getcontentpane().add(combobox_2);     combobox_2.setprototypedisplayvalue("xxxxxxxxxx");      string[] australia = { "new south wales", "tasmania", "queensland" ,"victoria"};     states.put(countries[1], australia);      string[] belgium = { "louxembourg", "hainaut", "flemish" };     states.put(countries[2], belgium);      string[] brazil = { "amazonas", "mato grosso" };     states.put(countries[3], brazil);      string[] canada = { "vancouver", "quebec" };     states.put(countries[4], canada);      string[] georgia = {"tbilisi", "s.ossetia" };     states.put(countries[5], georgia);      string[] greece = { "pelloponisos", "chalchidikis", "thesprotias" };     states.put(countries[6], greece);      string[] india = {  "jalpur", "kolkata", "new delhi" };     states.put(countries[7], india);      string[] lithuania = { "akmene", "kretinga", "varena" };     states.put(countries[8],lithuania);      string[] macedonia = {  "bitola", "struga", "veles" };     states.put(countries[9], macedonia);   } 

code imports data

   if ( studentid > 0 )  {                    //place comboboxez                   string sex=(string) combobox.getselecteditem();                 output.writeutf(sex);                  string country=(string) combobox_1.getselecteditem();                 output.writeutf(country);                   string state=(string) combobox_2.getselecteditem();                 output.writeutf(state);                    string month=(string) combobox_3.getselecteditem();                 output.writeutf(month);                  string day=(string) combobox_4.getselecteditem();                 output.writeutf(day);                  string year=(string) combobox_5.getselecteditem();                 output.writeutf(year);                   output.writeint(maths);                 output.writeint(buisness);                 output.writeint(programming);                 output.writeint(accounting);                 output.writeint(art);                 output.writeint(music); 

and actionperformed country state comboboxes

public void actionperformed( actionevent e )  {       //*************for state , country comboboxez*********************     string country = (string)combobox_1.getselecteditem();         object o = states.get( country );          if (o == null)         {             combobox_2.setmodel( new defaultcomboboxmodel<string>() );         }         else         {             combobox_2.setmodel( new defaultcomboboxmodel<string>( (string[])o ) );         }        //**********done state , country comboboxez********** 

this because part of code :

if (o == null) {     comboboxstate.setmodel( new defaultcomboboxmodel<string>() ); } else {     comboboxstate.setmodel( new defaultcomboboxmodel<string>( (string[])o ) ); } 

is before this:

if (e.getsource()==btnenter){     addrecord( ) ; } 

as such, combo box gets rearranged first, , record added.

if put second part before first one, works perfectly. that's it.

but, suggest check component caused action, , want do, else actions on components can cause operations expected other component perform. if want that, can experiment e.getactioncommand()