getlong_Java LocalDateTime类| 带示例的getLong（）方法

getlong

LocalDateTime类的getLong()方法 (LocalDateTime Class getLong() method)

getLong() method is available in java.time package.
getLong()方法在java.time包中可用。
getLong() method is used to get the value as long for the given temporal field from this date-time object.
getLong()方法用于从该日期时间对象获取给定时间字段的值。
getLong() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
getLong()方法是一个非静态方法，只能通过类对象访问，如果尝试使用类名称访问该方法，则会收到错误消息。
getLong() method may throw an exception at the time of returning value as long.
只要返回值的时间长， getLong()方法就可能引发异常。
- DateTimeException – This exception may throw when the given field couldn’t be generated.
- UnsupportedTemporalTypeException – This exception may throw when the given field is unsupported.
- ArithmeticException – This exception may throw when the calculated result exceeds the limit.

Syntax:

句法：

    public long getLong(TemporalField t_field);

Parameter(s):

参数：

TemporalField t_field – represents the field of the returned value.
TemporalField t_field –代表返回值的字段。

Return value:

返回值：

The return type of this method is long, it returns the value for the given field as long from this date-time.

此方法的返回类型为long ，它从该日期时间开始一直返回给定字段的值。

Example:

例：

// Java program to demonstrate the example 
// of getLong(TemporalField t_field) method 
// of LocalDateTime
import java.time.*;
import java.time.temporal.*;
public class GetLongOfLocalDateTime {
public static void main(String args[]) {
// Instantiates two LocalDateTime
LocalDateTime da_ti1 = LocalDateTime.parse("2005-10-05T10:10:10");
LocalDateTime da_ti2 = LocalDateTime.now();
// Display da_ti1, da_ti2
System.out.println("LocalDateTime da_ti1 and da_ti2: ");
System.out.println("da_ti1: " + da_ti1);
System.out.println("da_ti2: " + da_ti2);
System.out.println();
// Here, this method returns the given 
// field value from this date-time (da_ti1)
// i.e. here MONTH_OF_YEAR field value will
// be returned from this date-time object
// da_ti1
long get_val = da_ti1.getLong(ChronoField.MONTH_OF_YEAR);
// Display get_val
System.out.print("da_ti1.getLong(ChronoField.MONTH_OF_YEAR): ");
System.out.println(get_val);
// Here, this method returns the given field
// value from this date-time (da_ti2) i.e. here
// MICRO_OF_SECOND field value will be returned
// from this date-time object da_ti2
get_val = da_ti2.getLong(ChronoField.MICRO_OF_SECOND);
// Display get_val
System.out.print("da_ti2.getLong(ChronoField.MICRO_OF_SECOND): ");
System.out.println(get_val);
}
}

Output

输出量

LocalDateTime da_ti1 and da_ti2: 
da_ti1: 2005-10-05T10:10:10
da_ti2: 2020-06-05T03:01:53.798565da_ti1.getLong(ChronoField.MONTH_OF_YEAR): 10
da_ti2.getLong(ChronoField.MICRO_OF_SECOND): 798565