計算時間／效能

Posted by Bruce Tsai

狀況：用 System.currentTimeMillis()

long start = System.currentTimeMillis(); 
long time = System.currentTimeMillis() - start;

正確做法

• 常用的計時類別
  • com.google.common.base.Stopwatch
  • org.apache.commons.lang3.time.StopWatch
  • org.springframework.util.StopWatch

StopWatch stopwatch = new StopWatch();
stopwatch.start();
stopwatch.stop();
System.out.println(stopwatch);