Can't Read File After Building in java -

hey guys i've program read file

public static string readfileasstring(string filename){     bufferedreader reader;     try {         reader = new bufferedreader(new filereader(filename));         string line;         stringbuilder sb = new stringbuilder();         while ((line = reader.readline()) != null){             sb.append(line + "\n");         }         reader.close();         return sb.tostring();     } catch (filenotfoundexception ex) {         joptionpane.showmessagedialog(null, "file not found","error",joptionpane.error_message);     } catch (ioexception ex) {           logger.getlogger(tsst.class.getname()).log(level.severe, null, ex);     }       return null;   } 

and constructor

public tsst() {     initcomponents();     joptionpane.showmessagedialog(null, readfileasstring("test.txt"),"succes",joptionpane.default_option); } 

and file in application project if run file netbeans it's work normaly got need if build application got jar file , run got error file not found , same in writing

public static void writefile(string canonicalfilename, string text){   file file = new file (canonicalfilename);   bufferedwriter out;        try {          out = new bufferedwriter(new filewriter(file));          out.write(text);          out.close();      } catch (ioexception ex) {          logger.getlogger(tsst.class.getname()).log(level.severe, null, ex);      } } 

you're working netbeans thing after build application folder creat called dist here put test.txt