Spring计时器StopWatch
用法代码 返回结果是毫秒
一毫秒等于千分之一秒(0.001秒)。因此,如果你有一个以毫秒为单位的时间值,你可以通过将这个值除以1000来将其转换为秒。例如,500毫秒等于0.5秒。
import org.springframework.util.StopWatch;import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;public class AppTest3 {public static void main(String[] args) {StopWatch sw = new StopWatch();
List<String> list = new ArrayList<>();List<CompletableFuture<Void>> futures = new ArrayList<>();for (int i = 0; i < 1000; i++) {int finalI = i;CompletableFuture<Void> future = CompletableFuture.runAsync(() -> {synchronized (list){list.add("Hello"+ finalI);}});futures.add(future);}sw.start(" 数据库查询");
sw.stop();CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).join();System.out.println("Actual length: " + list.size());for (String s : list) {System.out.println(s);}sw.start(" 数据转换");
sw.stop();System.out.println(sw.prettyPrint()); }
}
直接结果

Spring StopWatch(多段统计)
StopWatch sw = new StopWatch();
sw.start(" 数据库查询");
sw.stop(); sw.start(" 数据转换");
sw.stop(); System.out.println(sw.prettyPrint());