java - JFrame GUI addition method not working -

okay have gui takes text input (say 10) , can check box want add initial amount (four choices 10, 20, 50, 100). after trying display sum of items in text frame.

int firstmuffler = integer.parseint(inputmufflers.gettext());     int firsttire = integer.parseint(inputtires.gettext());     int firstbreaks = integer.parseint(inputbreaks.gettext());     int firstmirrors = integer.parseint(inputmirrors.gettext());     if (muf10.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 10));      }     else if (muf20.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 20));     }     else if (muf50.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 50));     }     else if (muf100.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 100));     }     else if (t10.isselected()){         finalstockt.settext(string.valueof(firsttire + 10));     }     else if (t20.isselected()){         finalstockt.settext(string.valueof(firsttire + 20));     }     else if (t50.isselected()){         finalstockt.settext(string.valueof(firsttire + 50));     }     else if (t100.isselected()){         finalstockt.settext(string.valueof(firsttire + 100));     }     else if (b10.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 10));     }     else if (b20.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 20));     }     else if (b50.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 50));     }     else if (b100.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 100));     }     else if (m10.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 10));     }     else if (m20.isselected()){         finalstockm.settext(string.valueof(firstmirrors+ 20));     }     else if (m50.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 50));     }     else if (m100.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 100));     }else{      } 

this have, can't figure out making not work. because outputs finalstockmuf text box , rest don't work. have fill out make work, zeros.

note: muf10, t10, etc. check boxes values. firsttire, firstmug, etc. first price input, without check boxes checked.

when use else if ladder, need remember 1 option, meets requirements, executed. in example, implemented code responsible collecting , inserting data from/to multiple objects in 1 else if ladder. in effect, first option satisfied condition worked, , rest ignored. therefore, should change code this:

    if (muf10.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 10));     }     else if (muf20.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 20));     }     else if (muf50.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 50));     }     else if (muf100.isselected()){         finalstockmuf.settext(string.valueof(firstmuffler + 100));     }       //break , beginning of new else if structure,      if (t10.isselected()){         finalstockt.settext(string.valueof(firsttire + 10));     }     else if (t20.isselected()){         finalstockt.settext(string.valueof(firsttire + 20));     }     else if (t50.isselected()){         finalstockt.settext(string.valueof(firsttire + 50));     }     else if (t100.isselected()){         finalstockt.settext(string.valueof(firsttire + 100));     }      //break , beginning of new else if structure,      if (b10.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 10));     }     else if (b20.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 20));     }     else if (b50.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 50));     }     else if (b100.isselected()){         finalstockb.settext(string.valueof(firstbreaks + 100));     }      //break , beginning of new else if structure,      if (m10.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 10));     }     else if (m20.isselected()){         finalstockm.settext(string.valueof(firstmirrors+ 20));     }     else if (m50.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 50));     }     else if (m100.isselected()){         finalstockm.settext(string.valueof(firstmirrors + 100));     } 

and should work fine. next problem numberformatexception: input string: "", thrown when input text field empty. solve use:

int firstmuffler = (!inputmufflers.gettext().equals("")) ? integer.parseint(inputmufflers.gettext()) : 0; 

...and similar solution every next jtextfield. code checks if jtextfield empty, , if is, gives 0 value firstmuffler. doesn't fill jtextfield '0'.

to fill output jtextfield not modified value of stock or input , output jtextfield '0' if there no input, enough add example:

    }else if(inputmufflers.gettext().equals("")){         inputmufflers.settext("0");         finalstockmuf.settext("0");     }else{         finalstockmuf.settext(inputmufflers.gettext());     } 

to end of every else if part. hope find answer useful.