如何在Joda Time/Java8中列出时区偏移量、时区ID和长名称？

Question

Joda Time的时区ID可以简单地用以下代码段显示。

Set<String> zoneIds = DateTimeZone.getAvailableIDs();

for(String zoneId:zoneIds) {
    System.out.println(zoneId);
}

但是，如何显示相应的时区偏移量、时区ID和长名称，使列表看起来如下所示？

(GMT-10:00) Pacific/Honolulu, Hawaii Standard Time
(GMT-10:00) Pacific/Johnston, Hawaii Standard Time
(GMT-10:00) Pacific/Fakaofo, Tokelau Time
(GMT-10:00) HST, Hawaii Standard Time

Set<String> zoneIds = DateTimeZone.getAvailableIDs();

for (String zoneId : zoneIds) {
    int offset = DateTimeZone.forID(zoneId).getOffset(new DateTime());
    String longName = TimeZone.getTimeZone(zoneId).getDisplayName();

    System.out.println("(" + offset + ") " + zoneId + ", " + longName);
}

(-36000000) Pacific/Honolulu, Hawaii Standard Time
(-36000000) Pacific/Johnston, Hawaii Standard Time
(-36000000) Pacific/Fakaofo, Tokelau Time
(-36000000) HST, Hawaii Standard Time

Answer 1

下面的方法起作用了。

import java.util.Set;
import java.util.TimeZone;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

Set<String> zoneIds = DateTimeZone.getAvailableIDs();
DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("ZZ");

for (String zoneId : zoneIds) {
    String offset = dateTimeFormatter.withZone(DateTimeZone.forID(zoneId)).print(0);
    String longName = TimeZone.getTimeZone(zoneId).getDisplayName();

    System.out.println("(" + offset + ") " + zoneId + ", " + longName);
}

可能还有其他更好的方法，我现在还不知道。

或

import java.util.Set;
import org.joda.time.DateTimeUtils;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

Set<String> zoneIds = DateTimeZone.getAvailableIDs();
DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("ZZ");

for (String zoneId : zoneIds) {
    String offset = dateTimeFormatter.withZone(DateTimeZone.forID(zoneId)).print(0);
    String longName = DateTimeZone.forID(zoneId).getName(DateTimeUtils.currentTimeMillis());

    System.out.println("(" + offset + ") " + zoneId + ", " + longName);
}

public String getName(long instant, Locale locale)

import java.util.Set;
import org.joda.time.DateTimeUtils;
import org.joda.time.DateTimeZone;
import org.joda.time.format.DateTimeFormat;
import org.joda.time.format.DateTimeFormatter;

Set<String> zoneIds = DateTimeZone.getAvailableIDs();
DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("ZZ");

for (String zoneId : zoneIds) {
    String offset = dateTimeFormatter.withZone(DateTimeZone.forID(zoneId)).print(0);
    String shortName = DateTimeZone.forID(zoneId).getShortName(DateTimeUtils.currentTimeMillis());

    System.out.println("(" + offset + ") " + zoneId + ", " + shortName);
}

public String getShortName(long instant, Locale locale)

import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.TextStyle;
import java.util.Locale;
import java.util.Set;

Set<String> zoneIds = ZoneId.getAvailableZoneIds();

for (String zoneId : zoneIds) {
    ZoneId zone = ZoneId.of(zoneId);
    ZonedDateTime zonedDateTime = ZonedDateTime.now(zone);

    ZoneOffset offset = zonedDateTime.getOffset();
    String longName = zone.getDisplayName(TextStyle.FULL, Locale.ENGLISH);

    System.out.println("(" + offset + ") " + zoneId + ", " + longName);
}

zone.getDisplayName(TextStyle.full,locale.English)将显示“印度时间”之类的长名称。然而，这不是一个全名，不像乔达时代。

下面将显示给定名称的全名，如“印度标准时间”（无论在适用的地方）。

DateTimeFormatter pattern = DateTimeFormatter.ofPattern("zzzz");
String longName = pattern.format(ZonedDateTime.now(ZoneId.of(zoneId)));

下面将显示给定区域的区域偏移量，如GMT+05:30（注意模式的大写）。

DateTimeFormatter pattern = DateTimeFormatter.ofPattern("ZZZZ");
String longName = pattern.format(ZonedDateTime.now(ZoneId.of(zoneId)));

DateTimeFormatter pattern = DateTimeFormatter.ofPattern("zzz");
String longName = pattern.format(ZonedDateTime.now(ZoneId.of(zoneId)));

https://docs.oracle.com/javase/8/docs/api/java/time/format/datetimeformatter.html