java - Array Out of Bounce Exception for Jar, but not Eclipse -

when convert java project jar file, arrayindexoutofbounds exception of -2 occurs in line 3 of section of code:

for (int = 0; < copy.get(copy.size() - 2).size(); i++) {     if (!copy.get(copy.size() - 2).get(i).tostring().equals(" ")) {         startlocations[index] = integer.parseint(copy.get(copy.size() - 2).get(i).tostring());         index++;     } } 

i find strange because program runs fine in eclipse, , size of copy, 2d arraylist tempoarily holding grid of maze 9. code fails when convert jar , run cmd. here full relevant code below. files in correct locations.

string filename = "maze.txt"; string line = null; arraylist < arraylist < square >> grid = new arraylist < arraylist < square >> ();  try {     // setup filereader, bufferedreader, , linereader     filereader filereader = new filereader(filename);     bufferedreader bufferedreader = new bufferedreader(filereader);      int row = 0;      // lines inside maze file     while ((line = bufferedreader.readline()) != null) {         arraylist < square > linelist = new arraylist < square > ();          (int = 0; < line.length(); i++) {             string letter = character.tostring(line.charat(i));              if (letter.equals("l")) {                 linelist.add(new lockedsquare(row, i, letter));             } else {                 linelist.add(new square(row, i, letter));             }              row++;         }          grid.add(linelist);     }      // cut down grid maze      arraylist < arraylist < square >> copy = grid;      int length = grid.size();      grid = new arraylist < arraylist < square >> ();      (int = 0; < length - 2; i++) {         grid.add(copy.get(i));     }      // start position      int[] startlocations = new int[2];      int index = 0;      (int = 0; < copy.get(copy.size() - 2).size(); i++) {         if (!copy.get(copy.size() - 2).get(i).tostring().equals(" ")) {             startlocations[index] = integer.parseint(copy.get(copy.size() - 2).get(i).tostring());             index++;         }     }      int playerx = startlocations[0];     int playery = startlocations[1]; } // exceptions catch (filenotfoundexception e) {     system.out.println("error: maze.txt not found"); } catch (ioexception ex) {     system.out.println("error reading maze.txt"); } 

this happening because jar file unable find maze.txt .

change string filename = "maze.txt"; string filename = <absolute-path-for-maze.txt> ; , should through in jar