java - Sorting a string of numbers with negative integers -

i have searched lot 2 days , not successful ,

now have strings 7 integer numbers ( both + , - ) separated comma .

i have written sample code explain .

        arraylist<string> str = new arraylist<string>();          str.add("9,-9,21,23,28,29,35");         str.add("18,18,-21,28,28,32,34");         str.add("-11,-11,22,28,29,-30,31");         str.add("8,-8,26,31,31,31,31");         str.add("8,8,26,-32,25,29,35");         str.add("10,9,-21,45,25,29,35");         str.add("-11,59,21,25,25,-29,35");         str.add("12,-9,21,55,25,29,15");         str.add("9,9,21,25,25,-29,35");         str.add("7,9,21,25,-35,25,35");         str.add("4,-39,21,-15,25,-29,35");         str.add("9,9,21,25,27,29,-35");         str.add("10,9,21,35,25,39,15");         str.add("8,-9,21,-25,25,29,-35");         str.add("18,-9,21,-23,25,29,-35");          collections.sort(str); 

this not return correct sorted array . tests first digit of numbers , proceed sorting .

but want , sorting must based on first numbers in string . if numbers same ( there 3 9 in first numbers of string arrays ), should check second numbers in those(tied strings alone) , sort accordingly , on .

the result should as

9 , -9 , 21 , 23 , 28 , 29 , 35 9 , 9 , 21 , 25 , 25 , -29 , 35 9 , 9 , 21 , 25 , 27 , 29 , -35 

is there method sort in method . please let me know if , related answers welcomed .

thanks in advance .

use comparing method comparator sort(list list, comparator c):

collections.sort(str, new comparator<string>(){                         public int compare(string str1, string str2){       int result = 0;       int = 0;       string [] s1 = str1.split(",");       string [] s2 = str2.split(",");       while ((i < s1.length) && (i < s2.length) && (result == 0)){         result = (integer.parseint(s1[i]) - integer.parseint(s2[i]));         i++;               }       return (result);     } });