計算程序從開始到結束使用了多少時間,是經常要做的事。
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class StopWatch {
private final static Logger LOG = LoggerFactory.getLogger(StopWatch.class);
// 程序開始運行的時間
private final long start;
public StopWatch() {
start = System.currentTimeMillis();
}
public double elapsedTime() {
long now = System.currentTimeMillis();
return (now - start) / 1000.0;
}
public void logElapsedTime(){
LOG.info("used time "+elapsedTime()+"s");
}
}