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📜  Java8 ZoneId类

📅  最后修改于: 2020-10-01 06:37:52             🧑  作者: Mango

Java ZoneId类

Java ZoneId类指定时区标识符，并提供在Instant和LocalDateTime之间进行转换的规则。它继承了Object类并实现了Serializable接口。

Java ZoneId类声明

我们来看一下java.time.ZoneId类的声明。

public abstract class ZoneId extends Object implements Serializable

Java ZoneId的方法

Method Description
String getDisplayName(TextStyle style, Locale locale) It is used to get the textual representation of the zone, such as ‘India Time’ or ‘+05:30’.
abstract String getId() It is used to get the unique time-zone ID.
static ZoneId of(String zoneId) It is used to obtain an instance of ZoneId from an ID ensuring that the ID is valid and available for use.
static ZoneId systemDefault() It is used to get the system default time-zone.
boolean equals(Object obj) It is used to check if this time-zone ID is equal to another time-zone ID.

Java ZoneId类示例

import java.time.*;
public class ZoneIdExample1 {
  public static void main(String... args) {
    ZoneId zoneid1 = ZoneId.of("Asia/Kolkata");
    ZoneId zoneid2 = ZoneId.of("Asia/Tokyo");
    LocalTime id1 = LocalTime.now(zoneid1);
    LocalTime id2 = LocalTime.now(zoneid2);
    System.out.println(id1);
    System.out.println(id2);
    System.out.println(id1.isBefore(id2));  
  }
}

输出：

14:28:58.230
17:58:58.230
true

Java ZoneId类示例：systemDefault()

import java.time.ZoneId;
public class ZoneIdExample2 {
  public static void main(String[] args) {
    ZoneId zone = ZoneId.systemDefault();   
    System.out.println(zone);
  } 
}

输出：

Asia/Kolkata

Java ZoneId类示例：getId()

import java.time.ZoneId;
public class ZoneIdExample3 {
  public static void main(String[] args) {
    ZoneId z = ZoneId.systemDefault();
    String s = z.getId();
    System.out.println(s);
  } 
}

输出：

Asia/Kolkata

Java ZoneId类示例：getDisplayName()

import java.util.Locale;
import java.time.ZoneId;
import java.time.format.TextStyle;
public class ZoneIdExample4 {
  public static void main(String[] args) {
    ZoneId z = ZoneId.systemDefault();
    System.out.println(z.getDisplayName(TextStyle.FULL, Locale.ROOT));
  } 
}

输出：

India Time