Java Instant isAfter()方法及示例

Instant类的 isAfter() 方法用于检查这个瞬间是否在作为参数传递的瞬间之后。该方法返回一个布尔值，显示相同的情况。

语法

public boolean isAfter(Instant otherInstant)

参数： 这个方法需要一个参数 otherInstant ，它是与这个瞬间比较的另一个瞬间。它不应该是空的。

返回： 如果这个时刻在指定的时刻之后，该方法返回 true 。否则，它返回false。

异常： 如果作为参数传递的otherInstant为空，该方法会抛出 NullPointerException 。

下面的程序说明了isAfter()方法。

程序1 :

// Java program to demonstrate
// Instant.isAfter() method
  
import java.time.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a Instant object
        Instant instant1
            = Instant.parse("2018-12-30T19:34:50.63Z");
  
        // create other Instant
        Instant instant2
            = Instant.parse("2018-12-29T09:24:00.63Z");
  
        // print instances
        System.out.println("Instance 1: " + instant1);
        System.out.println("Instance 2: " + instant2);
  
        // check if instant1 is after instant2
        // using isAfter()
        boolean value = instant1.isAfter(instant2);
  
        // print result
        System.out.println("Is Instant1 after Instant2: "
                           + value);
    }
}

输出:

Instance 1: 2018-12-30T19:34:50.630Z
Instance 2: 2018-12-29T09:24:00.630Z
Is Instant1 after Instant2: true

程序2

// Java program to demonstrate
// Instant.isAfter() method
  
import java.time.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a Instant object
        Instant instant1
            = Instant.parse("2018-10-30T19:34:50.63Z");
  
        // create other Instant
        Instant instant2 = Instant.now();
  
        // print instances
        System.out.println("Instance 1: " + instant1);
        System.out.println("Instance 2: " + instant2);
  
        // check if instant1 is after instant2
        // using isAfter()
        boolean value = instant1.isAfter(instant2);
  
        // print result
        System.out.println("Is Instant1 after Instant2: "
                           + value);
    }
}

输出:

Instance 1: 2018-10-30T19:34:50.630Z
Instance 2: 2018-11-27T04:52:08.970Z
Is Instant1 after Instant2: false

程序3： 显示由isAfter()抛出的异常。

// Java program to demonstrate
// Instant.isAfter() method
  
import java.time.*;
  
public class GFG {
    public static void main(String[] args)
    {
  
        // create a Instant object
        Instant instant1
            = Instant.parse("2018-10-30T19:34:50.63Z");
  
        // create other Instant
        Instant instant2 = null;
  
        try {
  
            // print instances
            System.out.println("Instance 1: " + instant1);
            System.out.println("Instance 2: " + instant2);
  
            // check if instant1 is after instant2
            // using isAfter()
            boolean value = instant1.isAfter(instant2);
        }
        catch (Exception e) {
            // print result
            System.out.println("Exception: " + e);
        }
    }
}

输出:

Instance 1: 2018-10-30T19:34:50.630Z
Instance 2: null
Exception: java.lang.NullPointerException

**参考资料: ** https://docs.oracle.com/javase/10/docs/api/java/time/Instant.html#isAfter(java.time.instant)