java - Best way of opening a file (and ensuring file is chosen) -

i have 2 seperate methods of opening file.

the first uses filechoser additional file type filter.

jfilechooser infilename = new jfilechooser();  filenameextensionfilter filter = new filenameextensionfilter("pcf & txt files", "pcf", "txt");  infilename.setfilefilter(filter);     component parent = null; int returnval = infilename.showopendialog(parent);` 

the second uses joptionpane has loop ensure directory chosen exists

string filepath; file directory;  do{   filepath = joptionpane.showinputdialog("please enter directory");    directory = new file(filepath);      if (directory.exists()==false){      joptionpane.showmessagedialog(null,"error directory");     }  }while(directory.exists()==false); 

i'm looking best of both here. able choose file, using file filter , loop function should directory not valid.

i've tried switching around variable names , various functions in different places cant seem loop (".exists" function) work.

you need modify jfilechooser code use loop.

jfilechooser infilename = new jfilechooser();  file file; boolean valid = false; while (!valid) {   int returnval = infilename.showopendialog(null);   if (returnval == jfilechooser.approve_option) {     file = infilename.getselectedfile();     valid = file.isdirectory();   else {     valid = returnval == jfilechooser.cancel_option;   } } 

its worth mentioning kind of thing might better achieved using;

jfilechooser.setfileselectionmode(jfilechooser.directories_only);