@Override public ArrayList<ArrayList<String>> convertToRowWise(DataSet dataSet) { ArrayList<ArrayList<String>> columnDataArrayList = new ArrayList<ArrayList<String>>(); ArrayList<ArrayList<String>> rowArrayList = new ArrayList<ArrayList<String>>(); for (int index = 0; index < dataSet.getColumns().size(); index++) { columnDataArrayList.add( dataSet.getData().get(dataSet.getColumns().get(index).getId()).getValues()); } for (int i = 0; i < columnDataArrayList.size(); i++) { ArrayList<String> colwisewRow = columnDataArrayList.get(i); for (int j = 0; j < colwisewRow.size(); j++) { if (i == 0) { ArrayList<String> temp = new ArrayList<String>(); rowArrayList.add(temp); } rowArrayList.get(j).add(colwisewRow.get(j)); } } return rowArrayList; }