Java 中的 Instant isBefore()方法，示例

原文:https://www . geesforgeks . org/instant-is before-method-in-Java-with-examples/

isBefore() 方法的即时类检查这个即时时间线位置是否在作为参数传递的即时之前。如果该时刻时间线位置在作为参数传递的时刻之前，则该方法将返回 true 或 false。比较是基于瞬间的时间线位置。

语法:

public boolean isBefore(Instant otherInstant)

参数:该方法取一个参数 otherInstant ，作为比较的另一个时刻。它不应为空。

返回:如果该时刻在指定时刻之前，则该方法返回真。

异常:如果 otherInstant 为空，该方法抛出空指针异常。

下面的程序说明了 isBefore()方法:

程序 1:

// Java program to demonstrate
// Instant.isBefore() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a Instant object
        Instant instant1
            = Instant.parse("2018-12-30T09:24:54.63Z");

        // create other Instant
        Instant instant2
            = Instant.parse("2018-12-31T01:34:00.63Z");

        // 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.isBefore(instant2);

        // print result
        System.out.println("Is Instant1 before Instant2: "
                           + value);
    }
}

输出:

Instance 1: 2018-12-30T09:24:54.630Z
Instance 2: 2018-12-31T01:34:00.630Z
Is Instant1 before Instant2: true

程序二:

// Java program to demonstrate
// Instant.isBefore() method

import java.time.*;

public class GFG {
    public static void main(String[] args)
    {

        // create a Instant object
        Instant instant1
            = Instant.parse("2018-11-27T09:24:54.63Z");

        // 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.isBefore(instant2);

        // print result
        System.out.println("Is Instant1 before Instant2: "
                           + value);
    }
}

输出:

Instance 1: 2018-11-27T09:24:54.630Z
Instance 2: 2018-11-27T04:55:36.127Z
Is Instant1 before Instant2: false

程序 3: 显示 isBefore 抛出的异常()

// Java program to demonstrate
// Instant.isBefore() 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.isBefore(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

参考文献:https://docs . Oracle . com/javase/10/docs/API/Java/time/instant . html # isb before(Java . time . instant)

版权属于：月萌API www.moonapi.com，转载请注明出处

本文链接：https://www.moonapi.com/news/21749.html