Quarkus GraalVM本机图像日期时间格式和本地化

Question

我尝试在java中使用本地化以本地样式打印日期。我已经使用数字和货币制作了类似的功能，但我未能将相同的行为应用到日期。

正如我在几天前发布此主题时所了解的，GraalVM Quarkus Locale在本机模式下，使用本机模式下的本地化需要使用创建一个“@AutomaticFeature”。

这个技巧适用于数字和货币：

@AutomaticFeature
public class NativeNumberFormatFeature implements Feature {

    @Override
    public void beforeAnalysis(BeforeAnalysisAccess access) {
        ImageSingletons
                .lookup(RuntimeClassInitializationSupport.class)
                .initializeAtBuildTime(NumberFormatSupport.class, this.getClass().getName());

        ImageSingletons.add(NumberFormatSupport.class, new NumberFormatSupport());
    }

}

public class NumberFormatSupport {

    private Map<Locale, NumberFormat> numberInstancesByLocale;
    private Map<Locale, Map<String, NumberFormat>> currencyInstancesByLocale;

    public NumberFormatSupport() {
        numberInstancesByLocale = new HashMap<>();
        currencyInstancesByLocale = new HashMap<>();
        for (Locale locale : Locale.getAvailableLocales()) {
            numberInstancesByLocale.put(locale, NumberFormat.getNumberInstance(locale));
            currencyInstancesByLocale.put(locale, new HashMap<>());
            for (Currency currency : Currency.getAvailableCurrencies()) {
                currencyInstancesByLocale.get(locale).put(currency.getCurrencyCode(), NumberFormat.getCurrencyInstance(locale));
                currencyInstancesByLocale.get(locale).get(currency.getCurrencyCode()).setCurrency(currency);
            }
        }
    }

    public NumberFormat getNumberFormat(Locale locale) {
        return (NumberFormat) numberInstancesByLocale.get(locale).clone();
    }

    public NumberFormat getCurrencyFormat(Locale locale, Currency currency) {
        return (NumberFormat) currencyInstancesByLocale.get(locale).get(currency.getCurrencyCode()).clone();
    }

}

但它不适用于DateTimeFormatter：

@AutomaticFeature
public class NativeDateFormatterFeature implements Feature {

    @Override
    public void beforeAnalysis(BeforeAnalysisAccess access) {
        ImageSingletons
                .lookup(RuntimeClassInitializationSupport.class)
                .initializeAtBuildTime(DateFormatterSupport.class, this.getClass().getName());

        ImageSingletons.add(DateFormatterSupport.class, new DateFormatterSupport());
    }
}

public class DateFormatterSupport {

    private Map<Locale, DateTimeFormatter> dateTimeFormatterByLocale;

    public DateFormatterSupport() {
        dateTimeFormatterByLocale = Arrays.stream(Locale.getAvailableLocales()).collect(Collectors.toMap(
            Function.identity(),
            l -> DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(l)));
    }

    public DateTimeFormatter get(Locale locale) {
        return dateTimeFormatterByLocale.get(locale);
    }

}

在开发模式下一切正常，但在原生模式下，语言环境被忽略。风格总是一样的，月份名称没有翻译。我在谷歌上寻找解决方案，但我没有找到任何东西，所以我在StackOverflow上询问。

如果需要，我随时为您服务。

你好，斯特凡。

Answer 1

我不明白为什么，但以下解决方案有效：

public class DateFormatterSupport {

    private Map<Locale, DateTimeFormatter> dateTimeFormatterByLocale;

    public DateFormatterSupport() {
        dateTimeFormatterByLocale = Arrays.stream(Locale.getAvailableLocales()).collect(Collectors.toMap(
            Function.identity(),
            l -> DateTimeFormatter.ofLocalizedDate(FormatStyle.MEDIUM).withLocale(l)));

        Arrays.stream(Locale.getAvailableLocales()).forEach(locale -> {
            dateTimeFormatterByLocale.get(locale).format(LocalDate.now());
        });
    }

    public DateTimeFormatter get(Locale locale) {
        return dateTimeFormatterByLocale.get(locale);
    }

}