java - Read text file to arrayList and sort -

this snippet of txt file "q.txt".

12.54778255173505 :      ^finishedline 15.416218875438748 :    ^finishedline 16.245508427720914 :  ^finishedline 9.595696051997852 :   &^finishedline 11.971100145959943 : ! '^finishedline 11.678678199807727 : " $^finishedline 14.905855346233682 : # %^finishedline 15.98343143372184 : $ "^finishedline 16.053542916378102 : % #^finishedline 

i need sort text file "q.txt" contains double , string. has been separated using " : " , @ end of each phrase there ("^finishedline"). when run this, coming "numberformatexception: empty string" error.

  public class sorting {        public static void sort() throws ioexception {          scanner s = new scanner(new file("q.txt"));         arraylist<qpair> set = new arraylist<>();         string line = "";         while (s.hasnext()) {           string[] parts = line.split(" : ");           set.add(new qpair(double.parsedouble(parts[0]), parts[1]));           s.usedelimiter("^finishedline");          }         s.close();        system.out.println(set);      }      private static class qpair{       private double d;       private string s;       public qpair(double d, string s){         this.d = d;         this.s = s;            }        public double getdouble(){         return d;       }        public string getstring(){         return s;       }      }      private static class qpaircompare implements comparator<qpair>{       public int compare(qpair x, qpair y){         return (int) (x.getdouble() - y.getdouble());        }     }    } 

as far can see: setting line empty string. enter while loop without changing line. split empty string @ :. admit had try out sure: yields array of 1 element, empty string. try parse empty string array double.

and tell numberformatexception: empty string. sounds agreement me.

i hope can figure out code line missing , should insert it?