java如何計算響應時長rt

import com.google.common.base.Stopwatch;

開始計時

Stopwatch stopwatch = Stopwatch.createStarted();

停止計時

stopwatch.stop();

計算出來的rt就是 

stopwatch.elapsed(TimeUnit.MILLISECONDS)

日誌輸出樣例

schedulingLogger.info("refresh[{}], gray:[{}], resultMap.size:[{}], elapsed(ms):[{}]",
    dbEventMessage.getDbEnum().getTableName(), gray, positionTagAndTerminalMap.size(), 
    stopwatch.elapsed(TimeUnit.MILLISECONDS));