Java TimeUnit toNanos()方法及示例

TimeUnit类 的 toNanos() 方法用于获取TimeUnit对象所代表的时间，作为1970年1月1日UTC午夜后的纳秒数。

语法：

public long toNanos(long duration)

参数： 该方法接受一个强制性参数 duration ，即以毫秒为单位的持续时间。

返回值： 该方法返回 转换后的持续时间 为纳秒。

以下程序说明了TimeUnit toNanos()方法的实现：

程序1：

// Java program to demonstrate
// toNanos() method of TimeUnit Class
 
import java.util.concurrent.*;
import java.util.Date;
 
class GFG {
    public static void main(String args[])
    {
        // Get current time in milliseconds
        long timeInMilliSec = new Date().getTime();
 
        // Create a TimeUnit object
        TimeUnit time = TimeUnit.MILLISECONDS;
 
        // Convert milliseconds to NanoSeconds
        // using toNanos() method
        System.out.println("Time " + timeInMilliSec
                           + " milliSeconds in NanoSeconds = "
                           + time.toNanos(timeInMilliSec));
    }
}

输出

Time 1539585501608 milliSeconds in NanoSeconds = 1539585501608000000

程序2：

// Java program to demonstrate
// toNanos() method of TimeUnit Class
 
import java.util.concurrent.*;
import java.util.Calendar;
 
class GFG {
    public static void main(String args[])
    {
        // Get current time in milliseconds
        long timeInMilliSec = Calendar
                                  .getInstance()
                                  .getTimeInMillis();
 
        // Create a TimeUnit object
        TimeUnit time = TimeUnit.MILLISECONDS;
 
        // Convert milliseconds to NanoSeconds
        // using toNanos() method
        System.out.println("Time " + timeInMilliSec
                           + " milliSeconds in NanoSeconds = "
                           + time.toNanos(timeInMilliSec));
    }
}

输出

Time 1539585503771 milliSeconds in NanoSeconds = 1539585503771000000