判断某一段语句执行需要多少时间

  首先添加maven依赖如下

 

<dependency>
    <groupId>com.google.guava</groupId>
    <artifactId>guava</artifactId>
    <version>12.0</version>
</dependency>

 

 

具体代码使用方式如下:

		Stopwatch stopwatch = new Stopwatch().start();

                //do something test

                for (int i = 0; i < 1000000; i++) {

                }

                long nanos = stopwatch.elapsed(TimeUnit.NANOSECONDS);

                System.out.println(nanos);