Java中的 SimpleTimeZone inDaylightTime() 方法及示例

Java中SimpleTimeZone 类的inDaylightTime( Date ) 方法用于检查和验证给定日期是否处于夏令时。

句法：

public boolean inDaylightTime(Date date)

参数：该方法接受一个Date类型的参数date，即要验证的给定日期。

返回值：如果传递的日期相对于夏令时无效，则该方法返回布尔值 True，否则该方法返回布尔值 False。

下面的程序说明了在Java中使用 inDaylightTime() 方法：
示例 1：

// Java code to demonstrate
// inDaylightTime() method
  
import java.util.*;
  
public class SimpleTimeZone_Demo {
    public static void main(String[] args)
    {
        // Creating a time zone object
        SimpleTimeZone simtimeobj
            = new SimpleTimeZone(540, "GMT");
  
        // Creating date object
        Date dt = new Date();
  
        // Verifying daylight
        boolean bool_daylight
            = simtimeobj.inDaylightTime(dt);
  
        // Checking the value of day light
        System.out.println("Is it in day"
                           + " light saving time? "
                           + bool_daylight);
    }
}

输出：

Is it in day light saving time? false

示例 2：

// Java code to demonstrate
// inDaylightTime() method
  
import java.util.*;
  
public class SimpleTimeZone_Demo {
    public static void main(String[] args)
    {
        // Creating a time zone object
        SimpleTimeZone simtimeobj
            = new SimpleTimeZone(400, "AUS");
  
        // 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 dt = c1.getTime();
  
        // Verifying daylight
        boolean bool_daylight
            = simtimeobj.inDaylightTime(dt);
  
        // Checking the value of day light
        System.out.println("Is it in day"
                           + " light saving time? "
                           + bool_daylight);
    }
}

输出：

Is it in day light saving time? false

参考： https: Java/util/SimpleTimeZone.html#inDaylightTime-java.util.Date-