Java tutorial
// Copyright 2015 HSL <https://www.hsl.fi> // This program is dual-licensed under the EUPL v1.2 and AGPLv3 licenses. package fi.hsl.parkandride.core.service; import fi.hsl.parkandride.core.back.RequestLogRepository; import fi.hsl.parkandride.core.domain.RequestLogKey; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.springframework.scheduling.annotation.Scheduled; import java.util.Map; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.atomic.LongAdder; import static java.util.stream.Collectors.toMap; public class BatchingRequestLogService { private static final Logger logger = LoggerFactory.getLogger(BatchingRequestLogService.class); private Map<RequestLogKey, LongAdder> requestLogBatch = new ConcurrentHashMap<>(); private final RequestLogRepository requestLogRepository; public BatchingRequestLogService(RequestLogRepository requestLogRepository) { this.requestLogRepository = requestLogRepository; } public void increment(RequestLogKey key) { final RequestLogKey roundedTimestamp = key.roundTimestampDown(); requestLogBatch.computeIfAbsent(roundedTimestamp, k -> new LongAdder()).increment(); } @Scheduled(cron = "${requestlog.cron:0 */5 * * * *}") public void updateRequestLogs() { logger.info("Update request logs"); final Map<RequestLogKey, LongAdder> previousMap = this.requestLogBatch; clearLogStash(); final Map<RequestLogKey, Long> requestCounts = previousMap.keySet().stream() .collect(toMap(key -> key, key -> previousMap.get(key).sum())); requestLogRepository.batchIncrement(requestCounts); } public void clearLogStash() { requestLogBatch = new ConcurrentHashMap<>(); } }