Help, the last part of my file goes missing

Question

I am adjusting my file so it fits a certain length. for example, 20 characters per line (the length is not fixed). I broke down the file into words and put it in an Arraylist(al), I check the length of the line and add a word if it is not over the limit then put the line in another ArrayList(adjLines) if the next word will cause it to exceed the limit. It is doing the job except for the last line where some words get cut-off so I'm wondering, what did I overlook in my code???
StringBuilder str = new StringBuilder(maxLength);
          String temp = "";
          int idx = 0;
          while(idx < al.size())
               temp = al.get(idx);
               if ((str.length() + temp.length()) <= maxLength) // FIX ADJUSTMENTS HERE!!!!!!!!!!
                    str.append(temp + " ");
                    idx++;
               else
                    adjLines.add(str.toString().trim());
                    str.delete(0,str.capacity());
             adjLines.add(temp)

Answer 1

Change the last line toadjLines.add(str.toString().trim());db