code: private List<Integer> getSplitPositions(String text) {
          ArrayList<Integer> splitPositions = new ArrayList<>();
          int position;
          int currentPosition = 0;
  
          while (true) {
              int indexOfMaru = text.indexOf("。", currentPosition);
              int indexOfTen = text.indexOf("、", currentPosition);
  
              if (indexOfMaru < 0 || indexOfTen < 0) {
                  position = Math.max(indexOfMaru, indexOfTen);
              } else {
                  position = Math.min(indexOfMaru, indexOfTen);
              }
  
              if (position >= 0) {
                  splitPositions.add(position);
                  currentPosition = position + 1;
              } else {
                  break;
              }
          }
  
          return splitPositions;
      }
docs: Split input text at 句読点, which is 。 and 、
  
  @param text
  @return list of split position