public void init(BytesRefArrayWritable cols) { for (int i = 0; i < prjColIDs.length; ++i) { int fieldIndex = prjColIDs[i]; if (fieldIndex < cols.size()) { fieldInfoList[fieldIndex].init(cols.unCheckedGet(fieldIndex)); } else { // select columns that actually do not exist in the file. fieldInfoList[fieldIndex].init(null); } } }