Java Date toInstant()方法及示例

Java中Date类的 toInstant() 方法用于将一个Date对象转换为一个Instant对象。在转换过程中会创建一个Instant，用来表示时间轴上与该Date相同的点。

语法

public Instant toInstant()

参数： 该方法不接受任何参数。

返回值： 该方法返回一个 Instant ，代表时间轴上与该Date相同的点。

下面的程序说明了toInstant()方法在Java中的应用：

例1 :

// Java code to demonstrate
// toInstant() method of Date class
  
import java.util.Date;
import java.util.Calendar;
import java.time.Instant;
  
public class GfG {
    public static void main(String args[])
    {
        // Creating a Calendar object
        Calendar c1 = Calendar.getInstance();
  
        // Set Month
        // MONTH starts with 0 i.e. ( 0 - Jan)
        c1.set(Calendar.MONTH, 00);
  
        // Set Date
        c1.set(Calendar.DATE, 30);
  
        // Set Year
        c1.set(Calendar.YEAR, 2019);
  
        // Creating a date object
        // with specified time.
        Date dateOne = c1.getTime();
  
        Instant inst = dateOne.toInstant();
  
        System.out.println(
            "Original Date: "
            + dateOne.toString());
        System.out.println(
            "Instant: " + inst);
    }
}

输出:

Original Date: Wed Jan 30 06:01:46 UTC 2019
Instant: 2019-01-30T06:01:46.730Z

例2 :

// Java code to demonstrate
// clone() method of Date class
  
import java.util.Date;
import java.util.Calendar;
import java.time.Instant;
  
public class GfG {
    public static void main(String args[])
    {
        // Creating a Calendar object
        Calendar c1 = Calendar.getInstance();
  
        // Set Month
        // MONTH starts with 0 i.e. ( 0 - Jan)
        c1.set(Calendar.MONTH, 06);
  
        // Set Date
        c1.set(Calendar.DATE, 12);
  
        // Set Year
        c1.set(Calendar.YEAR, 1996);
  
        // Creating a date object
        // with specified time.
        Date dateOne = c1.getTime();
  
        Instant inst = dateOne.toInstant();
  
        System.out.println(
            "Original Date: "
            + dateOne.toString());
        System.out.println(
            "Instant: " + inst);
    }
}

输出:

Original Date: Fri Jul 12 06:01:49 UTC 1996
Instant: 1996-07-12T06:01:49.766Z

参考资料: https://docs.oracle.com/javase/8/docs/api/java/util/Date.html#toInstant-