swing - Java JTable combobox validation -

there 3 things trying here:

1. first trying make combo box show "not feed" when u lanuch program, @ moment when launches shows nothing, when click on combo box shows option "feed" , "not feed".

2. secondly trying validation combobox, when click jbutton next, validate if combobox "feed" if go next, else have pop saying "check again"

3. lastly, make cells on first 4 col uneditable , last column editable.

   public class dosagetablehelper  { private static jtable todotable; private static jscrollpane jpane; private static int counter=1; public static defaulttablemodel getelderlyfromquerydos(string timing,string position) throws sqlexception {     sqlobject = new sqlobject();     resultset rs = null;      if(timing.equalsignorecase("morning")){         preparedstatement stmt  = so.getpreparedstatementwithkey("select morningdosage et_elderly name = ?");         stmt.setstring(1,position);         stmt.executequery();         system.out.println(stmt);         rs = stmt.getresultset();     }     else if(timing.equalsignorecase("afternoon")){         preparedstatement stmt  = so.getpreparedstatementwithkey("select afternoondosage et_elderly name = ?");         stmt.setstring(1,position);         stmt.executequery();         system.out.println(stmt);         rs = stmt.getresultset();     }     else if(timing.equalsignorecase("noon")){         preparedstatement stmt  = so.getpreparedstatementwithkey("select noondosage et_elderly name = ?");         stmt.setstring(1,position);         stmt.executequery();         system.out.println(stmt);         rs = stmt.getresultset();     }     return (defaulttablemodel) buildtablemodel(rs); }    @suppresswarnings("unchecked") public static defaulttablemodel buildtablemodel(resultset rs) throws sqlexception {     arraylist<dosageobject> dosagelist=null;       system.out.println(rs);     try {         while(rs.next()){             bytearrayinputstream in = new bytearrayinputstream(rs.getbytes(1));             objectinputstream = new objectinputstream(in);             object retrievedosblob =(object) is.readobject();             if(retrievedosblob instanceof  arraylist<?>){                 dosagelist=((arraylist<dosageobject>) retrievedosblob);             }         }     } catch (classnotfoundexception e) {          e.printstacktrace();     } catch (ioexception e) {          e.printstacktrace();     }      // storing array list in array list future uses      vector<string> columnnames = new vector<string>();      columnnames.add("description");     columnnames.add("prescription");     columnnames.add("medication type");     columnnames.add("dosage");     columnnames.add("checked");      vector<vector<object>> data = new vector<vector<object>>();          for(int k=0;k<dosagelist.size();k++){         vector<object> vector = new vector<object>();         vector.add(dosagelist.get(k).getmeddescrip());         vector.add(dosagelist.get(k).getmedprescrip());         vector.add(dosagelist.get(k).getmedtype());         vector.add(dosagelist.get(k).getmeddosage());          data.add(vector);     }       defaulttablemodel dtm = new defaulttablemodel(data, columnnames) {         private static final long serialversionuid = 4234183862785566645l;          @override         public boolean iscelleditable(int rowindex, int columnindex) {             return !( rowindex == 1 && columnindex == 1 );         }       };     return dtm; }   // debug-able main method public static void main(string[] args) throws sqlexception {     arraylist<string> namelist= new arraylist<string>();     namelist.add("lee ching chong");     namelist.add("lim kuay siak");     namelist.add("lee ching chong");      todotable =new jtable(getelderlyfromquerydos("morning",namelist.get(0)));       string[] values = new string[] { "not feed", "feed" };     tablecolumn col = todotable.getcolumnmodel().getcolumn(4);     col.setcelleditor(new mycomboboxeditor(values));     col.setcellrenderer(new mycomboboxrenderer(values));      jpane = new jscrollpane(todotable);     jpanel panel = new jpanel();     jframe frame = new jframe();     frame.setbounds(0, 0, 700, 543);     panel.add(jpane);     frame.getcontentpane().add(new jscrollpane(panel));      jbutton btnnext = new jbutton("next");     panel.add(btnnext);     frame.setvisible(true);     btnnext.addactionlistener(new actionlistener() {          public void actionperformed(actionevent e) {             try {                 todotable.setmodel(dosagetablehelper.getelderlyfromquerydos("morning",namelist.get(counter)));                 string[] values = new string[] { "not feed", "feed" };                 tablecolumn col = todotable.getcolumnmodel().getcolumn(4);                 col.setcelleditor(new mycomboboxeditor(values));                 col.setcellrenderer(new mycomboboxrenderer(values));             } catch (sqlexception e1) {                 // todo auto-generated catch block                 e1.printstacktrace();             }                counter++;          }      });  }    } @suppresswarnings("rawtypes") class mycomboboxrenderer extends jcombobox implements tablecellrenderer {  private static final long serialversionuid = 1319299961084034009l;  @suppresswarnings("unchecked") public mycomboboxrenderer(string[] items) {     super(items); }  public component gettablecellrenderercomponent(jtable table, object value, boolean isselected,         boolean hasfocus, int row, int column) {     if (isselected) {         setforeground(table.getselectionforeground());         super.setbackground(table.getselectionbackground());     } else {         setforeground(table.getforeground());         setbackground(table.getbackground());     }     setselecteditem(value);     return this; } } class mycomboboxeditor extends defaultcelleditor {  private static final long serialversionuid = -1702063500403826596l;  @suppresswarnings({ "rawtypes", "unchecked" }) public mycomboboxeditor(string[] items) {     super(new jcombobox(items)); } } 

sample output:

1. read oracle tutorial - how use tables - part use jcombobox tablecelleditor,

   • explanation jtable has 2 separate funcionalities tablecelleditor editing value stored in xxxtablemodel , tablecellrenderer painting value stored in xxxtablemodel,

   • after editing (event, notifiers implemented in apis) storing selected value tablecelleditor (jcombobox) xxxtablemodel using xxxtablemodel.setvalueat, store "feed" or "not feed", not jcombobox object, tablecellrenderer painting model view

   • by default works automatically using defaulttablemodel, there required override reduced numbers of methods (getcolumnclass, iscellediteble, in case setvalueat too)

2. there 2 ways (1st. required override xxxtablemodel.setvalueat)

   • jbutton disabled (programatically) untill value changed blank "feed" or "not feed", required loop inside model, note after code line super.setvalueat() executed, value editor stored model

   • action jbutton loops inside model (primitive, easiest, themost efficient validations, simple , direct code, without bugs inside xxxtablemodel.setvalueat)

3. required override xxxtablemodel.setvalueat , set, change iscelleditable(row, column) correct value, need create separate array iscelleditable, models events, don't change array outside, method xxxtablemodel.setvalueat can notifier

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• use defaulttablemodel if possible (to avoids missinterpretations in code required override abstracttablemodel, methods, listeners , models notifiers - firexxxxxx)

• code ordering inside model important, firstly to store value model, call changes, validations, additional code, code based on value stored in model

• i'm sure every 3 points here few times, including working code examples in sscce / mcve forms