computeIfAbsent-JZTXT

Map<String, Map<Integer, SalePriceLine>> ouLineMap = new HashMap<>(ouCodes.size());
for (int i = 0; i < lineList.size(); i++) {
SalePriceLine line = lineList.get(i);
ouLineMap.computeIfAbsent(line.getOuCode(), key -> new HashMap<>(16)).put(i, line);
}