Method compare

Result.java:9–36

(String box1, String box2)

    public static List<String> sortBoxes(List<String> boxList) {          
        Comparator<String> comparator = new Comparator<String>() {             
            @Override             
            public int compare(String box1, String box2) {                 
                // split each junction box into two parts identifier, content                 
                String[] split1 = box1.split(" ", 2);                 
                String[] split2 = box2.split(" ", 2);  

                boolean isDigit1 = Character.isDigit(split1[1].charAt(0));                 
                boolean isDigit2 = Character.isDigit(split2[1].charAt(0));                  
                
                // case 1). both boxes are letter-boxes                 
                if (!isDigit1 && !isDigit2) {                     
                    // first compare the content                     
                    int cmp = split1[1].compareTo(split2[1]);                     
                    if (cmp != 0)                         
                        return cmp;                     
                    // boxes of same content, compare the identifiers                     
                    return split1[0].compareTo(split2[0]);                 
                }                  
                // case 2). one of boxes is digit                 
                if (!isDigit1 && isDigit2)                     
                // the letter box comes before digit-boxes                     
                    return -1;                 
                else if (isDigit1 && !isDigit2)                     
                    return 1;                 
                else                     
                // case 3). both boxes are digit                     
                    return 0;             
            }         
        }; 
                 
        Collections.sort(boxList, comparator);