格式化时区显示名称（例如 UTC + 01:00）

Question

我有一个微调器，我可以从中选择所需的时区。当我select一个时区时，显示相关的当前时间。在微调器中，我想在这个配置中设置时区：例如America/Los_Angeles (UTC-07:00)。相反，我看到以下内容： America/Los_Angeles (UTC-28800000)。这是代码：

String[]TZ = TimeZone.getAvailableIDs();
String NameAndUTC ="";
for(int i = 0; i < TZ.length; i++)
{    
NameAndUTC = TimeZone.getTimeZone(TZ[i]).getID() + " (UTC" + 
             (TimeZone.getTimeZone(TZ[i]).getRawOffset() == 0 ? "+00:00" : 
             TimeZone.getTimeZone(TZ[i]).getRawOffset()) + ")";
}

Answer 1

我建议您从过时的 error-prone java.util date-time API 切换到 modern java.time date-time API. Learn more about the modern date-time API from Trail: Date Time.

如果您的 Android API 级别仍然不符合 Java8，请检查 and Java 8+ APIs available through desugaring。

使用 Java 现代 date-time API:

import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;

public class Main {
    public static void main(String[] args) {
        // Get the set of all time zone IDs.
        Set<String> allZones = ZoneId.getAvailableZoneIds();

        // Create a List using the set of zones and sort it. Now, you can display the
        // sorted list in the spinner
        List<String> zoneList = new ArrayList<String>(allZones);
        Collections.sort(zoneList);

        // Select a value from the spinner e.g.
        String s = "America/Los_Angeles";

        // Get the Zone Id using the selected value from the spinner
        ZoneId zone = ZoneId.of(s);

        // Date and time at the zone selected from the spinner
        ZonedDateTime zdt = ZonedDateTime.now(zone);

        // Define a formatter as per your display requirement e.g.
        DateTimeFormatter formatter = DateTimeFormatter.ofPattern("EEE MMM dd yyyy HH:mm:ss VV '(UTC'XXX')'");

        // Display the date time
        System.out.println(zdt.format(formatter));
    }
}

输出：

Thu Sep 03 2020 14:47:11 America/Los_Angeles (UTC-07:00)

格式化时区显示名称（例如 UTC + 01:00）

Formatting time zone display names (e.g. UTC + 01:00)

timezone

android

utc