TestUtils.java

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 * version 2 for more details (a copy is included in the LICENSE file that
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 * 2 along with this work; if not, write to the Free Software Foundation,
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import java.text.DecimalFormatSymbols;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.Locale;

import java.util.Locale.Builder;

/**
 * TestUtils provides utility methods to get a locale-dependent attribute.
 * For example,
 *   - whether or not a non-Gregorian calendar is used
 *   - whether or not non-ASCII digits are used
 *
 * This class was developed to help testing for internationalization &
 * localization and is not versatile.
 */
public class TestUtils {

    /**
     * Returns true if the give locale uses Gregorian calendar.
     */
    public static boolean usesGregorianCalendar(Locale locale) {
        return Calendar.getInstance(locale).getClass() == GregorianCalendar.class;
    }

    /**
     * Returns true if the given locale uses ASCII digits.
     */
    public static boolean usesAsciiDigits(Locale locale) {
        return DecimalFormatSymbols.getInstance(locale).getZeroDigit() == '0';
    }

    /**
     * Returns true if the given locale has a special variant which is treated
     * as ill-formed in BCP 47.
     *
     * BCP 47 requires a variant subtag to be 5 to 8 alphanumerics or a
     * single numeric followed by 3 alphanumerics.
     * However, note that this methods doesn't check a variant so rigorously
     * because this is a utility method for testing. Intended special variants
     * are: JP, NY, and TH, which can be commonly provided by
     * Locale.getAvailableLocales().
     *
     */
    public static boolean hasSpecialVariant(Locale locale) {
        String variant = locale.getVariant();
        return !variant.isEmpty()
                   && "JP".equals(variant) || "NY".equals(variant) || "TH".equals(variant);
    }

}