java - Remove columns from table view javafx -

i have table view in javafx , add dynamically columns because don't know number of columns. want when click in button rows , columns of tableview removed. have code below. want before add new data in table remove columns it. tried lot of things found online nothing worked. thanks.

public void handleeventsclick(){     string tablename = (string) events.getselectionmodel().getselecteditem();      observablelist<observablelist> transitionevents = fxcollections.observablearraylist();      tablecolumns = new tablecolumn[traev.size()];      int trevsize = 0;      for(int = 0; < traev.size();i++){         arraylist<transitionsubsequencepair> tep = traev.get(i);           tablecolumn tc = new tablecolumn("trev:" + i);         tablecolumns[i] = tc;             final int j = i;             tc.setcellvaluefactory(new callback<celldatafeatures<observablelist,string>,observablevalue<string>>(){                                     public observablevalue<string> call(celldatafeatures<observablelist, string> param) {                                                                                                                   return new simplestringproperty(param.getvalue().get(j).tostring());                                         }                                 });             eventstableview.getcolumns().addall(tc);     }      observablelist<string> row = fxcollections.observablearraylist();     row.clear();     for(int = 0; < traev.size();i++){         arraylist<transitionsubsequencepair> tep = traev.get(i);           arraylist<string> seentables = new arraylist<string>();         for(transitionsubsequencepair tre: tep){             system.out.println(tre.gettable());             string lala = "";             if(tre.gettable().equals(tablename) && (!seentables.contains(tre.gettable()) || seentables.isempty())){                 system.out.println(i);                 lala += tre.gettransition() + ":" + tre.getsubsequence() + ",";                 row.add(lala);                 seentables.add(tre.gettable());             }             system.out.println("--"+lala);         }       }     transitionevents.add(row);       eventstableview.setitems(transitionevents); // add data tableview   } 

to remove data:

eventstableview.getitems().clear(); 

to remove columns:

eventstableview.getcolumns().clear();