Java即时类| plus（）方法与示例

即时类plus()方法 (Instant Class plus() method)

Syntax:

句法：

    public Instant plus(TemporalAmount t_amt);
public Instant plus(long amt, TemporalUnit t_unit);

plus() method is available in java.time package.
plus()方法在java.time包中可用。
plus(TemporalAmount t_amt) method is used to add the given amount to this Instant and return the Instant.
plus(TemporalAmount t_amt)方法用于将给定金额添加到此Instant并返回Instant。
plus(long amt, TemporalUnit t_unit) method is used to add the given amount in the given unit to this Instant and return the Instant.
plus(long amt，TemporalUnit t_unit)方法用于将给定单位的给定金额添加到此Instant并返回Instant。
These methods may throw an exception at the time of performing addition.
这些方法在执行加法时可能会引发异常。
- ArithmeticException: This exception may throw when the calculated result exceeds the limit to represent this object.ArithmeticException ：当计算结果超出表示此对象的限制时，可能引发此异常。
- UnsupportedTemporalTypeException: This exception may throw when the given unit is unsupported.UnsupportedTemporalTypeException ：当不支持给定单元时，可能引发此异常。
- DateTimeException: This exception may throw when getting any error during addition.DateTimeException ：在添加过程中出现任何错误时，可能引发此异常。
These are non-static methods and it is accessible with class objects and if we try to access these methods with the class name then we will get an error.
这些是非静态方法，可通过类对象访问，如果尝试使用类名访问这些方法，则会收到错误消息。

Parameter(s):

参数：

In the first case, "plus(TemporalAmount t_amt)",
在第一种情况下，“ plus(TemporalAmount t_amt)”
- TemporalAmount t_amt – represents the amount to be added to this Instant.
- TemporalAmount t_amt –表示要添加到此Instant的数量。
In the second case, "plus(long amt, TemporalUnit t_unit)",
在第二种情况下，“ plus(long amt，TemporalUnit t_unit)”，
- long amt – represents the amount in units to be added to this Instant.
- long amt –表示要添加到此Instant的单位数量。
- TemporalUnit t_unit – represents the unit to measure the given amount.
- TemporalUnit t_unit –代表测量给定数量的单位。

Return value:

返回值：

In both the cases, the return type of the method is Instant,

在这两种情况下，方法的返回类型均为Instant 。

In the first case, it returns the Instant that holds the value added the given amount to this Instant.
在第一种情况下，它返回包含将给定金额添加到此Instant的值的Instant。
In the second case, it returns the Instant that holds the value added the given amount in unit to this Instant.
在第二种情况下，它会返回即时值，该值保存将给定值添加到此即时值中的值。

Example:

例：

// Java program to demonstrate the example 
// of plus() method of Instant
import java.time.*;
import java.time.temporal.*;
public class PlusOfInstant {
public static void main(String args[]) {
long amt = 2;
// Instantiates two Instant and
// a Duration object
Instant ins1 = Instant.parse("2006-04-03T05:10:15.00Z");
Instant ins2 = Instant.now();
Duration du = Duration.ofSeconds(2);
// Display ins1,ins2
System.out.println("Instant ins1 and ins2: ");
System.out.println("ins1: " + ins1);
System.out.println("ins2: " + ins2);
System.out.println("amt to add: " + amt);
System.out.println("du to add: " + du);
System.out.println();
// Here, this method adds the given amount
// in the given unit with this Instant and
// returns the Instant i.e. here we are
// adding 2 hours with Instant ins1
Instant plus_val = ins1.plus(amt, ChronoUnit.HOURS);
// Display plus_val
System.out.println("ins1.plus(amt,ChronoUnit.HOURS): " + plus_val);
// Here, this method adds the given amount
// with this Instant and returns the Instant 
// i.e. here we are adding 2 seconds
// with Instant ins2
plus_val = ins2.plus(du);
// Display plus_val
System.out.println("ins2.plus(du): " + plus_val);
}
}

Output

输出量

Instant ins1 and ins2: 
ins1: 2006-04-03T05:10:15Z
ins2: 2020-05-28T07:28:15.161687Z
amt to add: 2
du to add: PT2Sins1.plus(amt,ChronoUnit.HOURS): 2006-04-03T07:10:15Z
ins2.plus(du): 2020-05-28T07:28:17.161687Z